uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   4 RATVICEHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKARDTLHHVFEASVVNIAQA 83
Cdd:cd04667    2 RATVICRRGDRILLVARRGGRWLLPGGKIEPGESPLEAAIRELKEETGLAALSLLYLFEHEGPHKLHHVFLAEAPDGGRP 81

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 814584484  84 RPCNEIIDCRWHAYSAMDELDTTDTTRHIVKSFLRR 119
Cdd:cd04667   82 RPGNEIARCRWVSADQLRDLNLSRATRLIVRRYLRR 117

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   4 RATVICEHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKARDTLHHVFEASVVNIAQA 83
Cdd:cd04667    2 RATVICRRGDRILLVARRGGRWLLPGGKIEPGESPLEAAIRELKEETGLAALSLLYLFEHEGPHKLHHVFLAEAPDGGRP 81

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 814584484  84 RPCNEIIDCRWHAYSAMDELDTTDTTRHIVKSFLRR 119
Cdd:cd04667   82 RPGNEIARCRWVSADQLRDLNLSRATRLIVRRYLRR 117

NUDIX domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484    7 VICEHEGHILFVR----KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELK----------ARDTLHHV 72
Cdd:pfam00293   9 VLLNEKGRVLLVRrskkPFPGWWSLPGGKVEPGETPEEAARRELEEETGLEPELLELLGSLHylapfdgrfpDEHEILYV 88

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 814584484   73 FEASVVNIAQARPCNEIIDCRWHAYSAMDELDTTDTTRHIVKSF 116
Cdd:pfam00293  89 FLAEVEGELEPDPDGEVEEVRWVPLEELLLLKLAPGDRKLLPWL 132

nucleoside triphosphatase YtkD; The functional assignment to the proteins of this family is contentious, with papers disagreeing in both interpretation and enzyme assay results. This protein belongs to the nudix family and shares some sequence identity with E. coli MutT but appears not to be functionally interchangeable with it. [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484    7 VICEHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQ----ELKARDTLHHVFEASVVNIAQ 82
Cdd:TIGR02705  29 VIPRYKDQWLLTEHKRRGLEFPGGKVEPGETSKEAAIREVMEETGAIVKELHYIGqyevEGESTDFVKDVYFAEVSALES 108

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   4 RATVICEHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKARDTLHHVFEASVVNIAQA 83
Cdd:cd04667    2 RATVICRRGDRILLVARRGGRWLLPGGKIEPGESPLEAAIRELKEETGLAALSLLYLFEHEGPHKLHHVFLAEAPDGGRP 81

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 814584484  84 RPCNEIIDCRWHAYSAMDELDTTDTTRHIVKSFLRR 119
Cdd:cd04667   82 RPGNEIARCRWVSADQLRDLNLSRATRLIVRRYLRR 117

NUDIX hydrolase superfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   5 ATVICEHEGHILFVRKARS----KWALPGGKVERDERPVGAAERELEEETGLNVDGLLYL------QELKARDTLHHVFE 74
Cdd:cd02883    4 GAVVFDDEGRVLLVRRSDGpgpgGWELPGGGVEPGETPEEAAVREVREETGLDVEVLRLLgvyefpDPDEGRHVVVLVFL 83

                         90       100
                 ....*....|....*....|.
gi 814584484  75 ASVVNIAQARPC-NEIIDCRW 94
Cdd:cd02883   84 ARVVGGEPPPLDdEEISEVRW 104

NUDIX domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484    7 VICEHEGHILFVR----KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELK----------ARDTLHHV 72
Cdd:pfam00293   9 VLLNEKGRVLLVRrskkPFPGWWSLPGGKVEPGETPEEAARRELEEETGLEPELLELLGSLHylapfdgrfpDEHEILYV 88

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 814584484   73 FEASVVNIAQARPCNEIIDCRWHAYSAMDELDTTDTTRHIVKSF 116
Cdd:pfam00293  89 FLAEVEGELEPDPDGEVEEVRWVPLEELLLLKLAPGDRKLLPWL 132

RNA pyrophosphohydrolase; The initiation of mRNA degradation often requires deprotection of its 5' end. In eukaryotes, the 5'-methylguanosine (cap) structure is principally removed by the NUDIX family decapping enzyme Dcp2, yielding a 5'-monophosphorylated RNA that is a substrate for 5' exoribonucleases. In bacteria, the 5'-triphosphate group of primary transcripts is also converted to a 5' monophosphate by a NUDIX protein called RNA pyrophosphohydrolase (RppH), allowing access to both endo- and 5' exoribonucleases. NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   5 ATVICEHEGHILFVR-KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKARDTLHH----VFEASVVN 79
Cdd:cd04665    3 VVVIARYKGKWLFTRhKERRGWEFPGGKREPGETIEEAARRELYEETGAVIFELKPLGQYSVHGKGQEffgaVYYAEVKS 82

                         90       100
                 ....*....|....*....|....*
gi 814584484  80 IAQARPCNEIIDCRWhaysaMDELD 104
Cdd:cd04665   83 FEPILPYFETAEVRL-----FDELP 102

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 814584484   7 VICEHEGHILFVRKARS----KWALPGGKVERDERPVGAAERELEEETGLNVDGLLYL 60
Cdd:cd04681   11 VIIRNEGEILFVRRAKEpgkgKLDLPGGFVDPGESAEEALRRELREELGLKIPKLRYL 68

bifunctional NMN adenylyltransferase/ADP-ribose pyrophosphatase and similar proteins; Bacterial NadM-Nudix is a bifunctional enzyme containing a nicotinamide mononucleotide (NMN) adenylyltransferase (NMNAT) and an ADP-ribose pyrophosphatase (ADPRase) domain. NMNAT was initially identified as an NAD+ synthase that catalyzes the reversible conversion of NMN to NAD+ in the final step of both the de novo biosynthesis and salvage pathways in most organisms across all three kingdoms of life ADPRase is a member of the NUDIX family proteins, catalyzes the metal-induced and concerted general acid-base hydrolysis of ADP ribose (ADPR) into AMP and ribose-5'-phosphate (R5P). Additional members in this cd include bacterial transcriptional regulator, NrtR, which represses the transcription of NAD biosynthetic genes in vitro and adenosine diphosphate ribose (ADPR), as well as NadQ, a NUDIX-like ATP-responsive regulator of NAD biosynthesis. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belong to this superfamily requires a divalent cation, such as Mg2+ or Mn2+ for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, U=I, L or V) which functions as metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   8 ICEHEGHILFVRKARS----KWALPGGKVERDERPVGAAERELEEETGLNVdglLYLQELKA-----RDTLHHVFeaSVV 78
Cdd:cd18873   12 FDDGELKVLLIKRKNEpfkgGWALPGGFVREDETLEDAARRELREETGLKD---IYLEQLGTfgdpdRDPRGRVI--SVA 86

                         90       100
                 ....*....|....*....|....
gi 814584484  79 NIA-------QARPCNEIIDCRWH 95
Cdd:cd18873   87 YLAlvpeedlAPKAGDDAAEARWF 110

ADP-ribose pyrophosphatase, UDP-glucose pyrophosphatase, and similar proteins; ADP-ribose pyrophosphatase (ADPRase) ( NUDIX (Nucleoside diphosphate-linked moiety X)) motif 5; Nudt5) catalyzes the hydrolysis of ADP-ribose and a variety of additional ADP-sugar conjugates to AMP and ribose-5-phosphate. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. UDP-glucose pyrophosphatase (UGPPase) (EC 3.6.1.45; also known as nucleoside diphosphate-linked moiety X)) motif 14; Nudt14) hydrolyzes the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. In mammals, UDP-glucose is the glucosyl donor for the synthesis of the storage polysaccharide glycogen. UGPPase, as a regulator of UDP-glucose, could play a regulatory role, but it has been shown to prefer ADP-ribose over UDP-glucose. Like other members of the NUDIX hydrolase superfamily, it requires a divalent cation, such as Mg2+, for its activity. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484  12 EGHILFV---RKARSK--WALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKA----RDTLHHVFEASVVNIAQ 82
Cdd:cd03424   13 DGKVVLVrqyRHPVGRvlLELPAGKIDPGEDPEEAARRELEEETGYTAGDLELLGSFYPspgfSDERIHLFLAEDLTPVS 92

                         90
                 ....*....|....
gi 814584484  83 ARPC--NEIIDCRW 94
Cdd:cd03424   93 EQALdeDEFIEVVL 106

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 814584484   7 VICEHEGHILF---VRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGL 57
Cdd:cd18875    8 MIYDGEDRVLVldrVKKDWGGYTFPGGHVEPGESFVDSVIREVKEETGLTIKNP 61

mRNA decapping enzyme 2; mRNA decapping enzyme 2 (Dcp2p; EC 3.6.1.62), nucleoside diphosphate linked moiety X))-type motif 20/Nudt20, is required for degradation of mRNAs, both in normal mRNA turnover, and in nonsense-mediated mRNA decay (NMD). Its catalytic subunit, and Dcp1p are the two components of the decapping enzyme complex. Decapping is a key step in both general and nonsense-mediated 5'->3' mRNA-decay pathways. Dcp2p contains an all-alpha helical N-terminal domain and a C-terminal domain which has the NUDIX fold. While decapping is not dependent on the N-terminus of Dcp2p, it does affect its efficiency. Dcp1p binds the N-terminal domain of Dcp2p stimulating the decapping activity of Dcp2p. Decapping permits the degradation of the transcript and is a site of numerous control inputs. It is responsible for nonsense-mediated decay as well as AU-rich element (ARE)-mediated decay. In addition, it may also play a role in the levels of mRNA. Enzymes belonging to the NUDIX hydrolase superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V).

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484  14 HILFVR--KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLL----YLQELKARDTL-----HHVFEASVVNiAQ 82
Cdd:cd03672   15 KVLLVKgwKSNSSWGFPKGKINKDESDADCAIREVYEETGFDISDLIndkdYIELTINGQRVrlyiiPGVPEDTPFE-PQ 93

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*
gi 814584484  83 ARpcNEIIDCRWHaysAMDELDTTDTTRHI-------VKSFLRRL 120
Cdd:cd03672   94 TR--KEISKIEWF---DIDDLPKNKKKKGKnsnkfymVNPFVKPL 133

MutT homolog-1 (MTH1); MutT homolog-1 (MTH1; EC 3.6.1.- ), also called nucleoside diphosphate-linked moiety X)) motif 1 (Nudt1), is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 814584484  13 GHILFVRKAR----SKWALPGGKVERDERPVGAAERELEEETGLNVdgllylQELKARDTLHHVFEASVVNI 80
Cdd:cd03427   13 DRVLLGLKKRgfgaGKWNGFGGKVEPGETIEEAAVRELEEEAGLTA------TELEKVGRLKFEFPDDPEAM 78

diadenosine hexaphosphate (Ap6A) hydrolase; Diadenosine hexaphosphate (Ap6A) hydrolase is a member of the NUDIX hydrolase superfamily. Ap6A hydrolase specifically hydrolyzes diadenosine polyphosphates, but not ATP or diadenosine triphosphate, and it generates ATP as the product. Ap6A, the most preferred substrate, hydrolyzes to produce two ATP molecules, which is a novel hydrolysis mode for Ap6A. These results indicate that Ap6A hydrolase is a diadenosine polyphosphate hydrolase. It requires the presence of a divalent cation, such as Mn2+, Mg2+, Zn2+, and Co2+, for activity. Members of the NUDIX hydrolase superfamily are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484  15 ILFVRKARS-KWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQE------LKARDTLHHV--FEASVVNIAQARP 85
Cdd:cd03673   18 VLLIHRPRYdDWSLPKGKLEPGETPEEAAVREVEEETGLRVRLGRPLGTtrytytRKGKGILKKVhyWLMRALGGEFLPQ 97

                         90       100       110
                 ....*....|....*....|....*....|....
gi 814584484  86 CNEIID-CRWHAYSAMDELDTTDTTRHIVKSFLR 118
Cdd:cd03673   98 PEEEIDeVRWLPPDEARRLLTYPSDREVLDAALE 131

CDP-Choline Pyrophosphatase and similar proteins; Members include: CDP-Choline Pyrophosphatase, ADP-ribose pyrophosphatase, and UDP-X diphosphatase. CDP-choline pyrophosphatase catalyzes the hydrolysis of CDP-choline to produce CMP and phosphocholine. ADP-ribose pyrophosphatase catalyzes the hydrolysis of ADP-ribose to AMP and ribose-5-P. UDP-X diphosphatase hydrolyzes UDP-N-acetylmuramic acid and UDP-N-acetylmuramoyl-L-alanine. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 814584484   3 IRATVIceHEGHILFVR-KARSKWALPGGKVERDERPVGAAERELEEETGLNV 54
Cdd:cd04672    5 VRAAVF--KDGKILLVReKSDGRWTLPGGWADVGLSPAENAVKEVREESGYEV 55

CDP-choline pyrophosphatase; CDP-choline pyrophosphatase catalyzes the hydrolysis of CDP-choline to produce CMP and phosphocholine. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   1 MKIRAtVICEHEGHILFVR-KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELKARD-----TLHHVFE 74
Cdd:cd18890    3 VDIRA-VVFNDKEEILLVKeKEDGKWTLPGGWADVGYTPTEVAAKEVEEETGLEVSPKKLLAILDKRKhphppQPTYVYK 81

                         90       100       110
                 ....*....|....*....|....*....|....*....
gi 814584484  75 ASV---VNIAQARPCNEIIDCRWHAYSAMDELDTTDTTR 110
Cdd:cd18890   82 LFIlceIEGGELKPSFETGEVRFFSENELPELSTDRVTE 120

Antisense Basic Fibroblast Growth Factor; Antisense Basic Fibroblast Growth Factor (ASFGF2; EC 3.6.1.-), also known as nucleoside diphosphate-linked moiety X)) motif 6/Nudt6, and similar proteins including peroxisomal coenzyme A diphosphatase/Nudt7 and mitochondrial coenzyme A diphosphatase/Nudt8. The Nudt6 gene overlaps and lies on the opposite strand from FGF2 gene, and is thought to be the FGF2 antisense gene. The two genes are independently transcribed, and their expression shows an inverse relationship, suggesting that this antisense transcript may regulate FGF2 expression. This gene has also been shown to have hormone-regulatory and antiproliferative actions in the pituitary that are independent of FGF2 expression. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   5 ATVICEHEGHILFVR---KARSKWALPGGKVERDERPVGAAERELEEETGLNV--DGLLYLqelkaRDTLHHVFEAS--- 76
Cdd:cd04670    6 GGLVINENNEVLVVQekyGGPGGWKLPGGLVDPGEDIGEAAVREVFEETGIDTefVSILGF-----RHQHPGRFGKSdly 80

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|...
gi 814584484  77 ------VVNIAQARPC-NEIIDCRWhaysaMD--ELDTTDTTRHIVKSFLRRL 120
Cdd:cd04670   81 fvcrlrPLSDEEIKICpEEIAEAKW-----MPleEYLKQPNVSQINKLVAKLL 128

ADP-ribose pyrophosphatase and similar proteins; ADP-ribose pyrophosphatase (ADPRase; EC 3.6.1.13) catalyzes the hydrolysis of ADP-ribose to AMP and ribose-5-P. Like other members of the NUDIX hydrolase superfamily of enzymes, it is thought to require a divalent cation, such as Mg2+, for its activity. It also contains a 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. In humans, there are four distinct ADPRase activities, three putative cytosolic (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). ADPRase-m is also known as NUDT9. It can be distinugished from the cytosolic ADPRase by a N-terminal target sequence unique to mitochondrial ADPRase. NUDT9 functions as a monomer.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   3 IRATVICEHEGHILFVRKARSK---WALPGGKVERDERPVGAAERELEEETGLNVD--GLLYLQE----LKARDTLHHVF 73
Cdd:cd18880    2 IRAKAIIIEDGKLLLVKHRDEGgifYILPGGGQEHGETLPEALKRECLEETGLDVEvgDLLFVREyigpNKPVHQVELFF 81

                 ....*
gi 814584484  74 EASVV 78
Cdd:cd18880   82 LCTLE 86

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 814584484   5 ATVICEHEGHILFVRKARS-KWALPGGKVERDERPVGAAERELEEETGLNV 54
Cdd:cd04676   21 AAVILNEDGRILLQRKGGLgLWSLPAGAIEPGEHPAEAVIREVREETGLLV 71

UDP-X diphosphatase; UDP-X diphosphatase hydrolyzes UDP-N-acetylmuramic acid and UDP-N-acetylmuramoyl-L-alanine, the last step of the Mur pathway of peptidoglycan biosynthesis. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   2 KIRATVICEHEGHILFVRKARSK-WALPGGKVERDERPVGAAERELEEETGLNVDgllyLQELKA-RDTLHH-------- 71
Cdd:cd18891    2 KVDVRAFIQNENKVLLVQDKHTKeWALPGGFAEVGLSPKENILKEVKEETGLHVE----VERLLAvFDTDLRqdipqsfq 77

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|..
gi 814584484  72 ----VFEASVVNIaQARPCNEIIDCRWHAYSAMDELDTTDTT 109
Cdd:cd18891   78 yykfIFACKILDG-EFQENSETSDLQYFSLDQLPNLSLKRTT 118

nucleoside triphosphatase YtkD; The functional assignment to the proteins of this family is contentious, with papers disagreeing in both interpretation and enzyme assay results. This protein belongs to the nudix family and shares some sequence identity with E. coli MutT but appears not to be functionally interchangeable with it. [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484    7 VICEHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQ----ELKARDTLHHVFEASVVNIAQ 82
Cdd:TIGR02705  29 VIPRYKDQWLLTEHKRRGLEFPGGKVEPGETSKEAAIREVMEETGAIVKELHYIGqyevEGESTDFVKDVYFAEVSALES 108

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   7 VICEHEGHILFVRKA-RSKWALPGGKVERDERPVGAAERELEEETGLN--VDGLLYLQELKAR--------DTLHHVFEA 75
Cdd:cd18879   24 VVLRDAGRVLLVRRAdNGRWTPVTGIVEPGEQPADAAVREVLEETGVDveVERLASVGASPPVtypngdqcQYLDLTFRC 103

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 814584484  76 SVVNiAQARPCN-EIIDCRWHAYSAMDELDTTDTTR 110
Cdd:cd18879  104 RPVG-GEARVNDdESLEVGWFPVDALPPMLPRFRRR 138

Adp-ribose pyrophosphatase (ADPRase) found in Thermus thermophilus, and similar proteins; ADP-ribose pyrophosphatase (ADPRase) such as found in extreme thermophile Thermus thermophilus (TtADPRase) catalyzes the hydrolysis of ADPR to AMP and ribose 5'-phosphate in the presence of Mg2+ and Zn2+ ions. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. UDP-glucose pyrophosphatase (UGPPase) (EC 3.6.1.45; also known as nucleoside diphosphate-linked moiety X)) motif 14; Nudt14) hydrolyzes the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. In mammals, UDP-glucose is the glucosyl donor for the synthesis of the storage polysaccharide glycogen. UGPPase, as a regulator of UDP-glucose, could play a regulatory role, but it has been shown to prefer ADP-ribose over UDP-glucose. Like other members of the NUDIX hydrolase superfamily, it requires a divalent cation, such as Mg2+, for its activity. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   7 VICEHEGHILFVRKAR-----SKWALPGGKVERDERPVGAAERELEEETGLNVDgLLYLQELKAR----DTLHHVFEASV 77
Cdd:cd24160   26 VLALREGRMLFVRQMRpavgaATLEIPAGLIDPGETPEEAARRELAEETGLSGD-LTYLTRFYVSpgfcDEKLHVFLAEN 104

                         90       100
                 ....*....|....*....|
gi 814584484  78 VNIAQARPC-NEIIDCRWHA 96
Cdd:cd24160  105 LREVEAHPDeDEAIEVVWMR 124

MutT pyrophosphohydrolase; The MutT pyrophosphohydrolase is a prototypical NUDIX hydrolase that catalyzes the hydrolysis of nucleoside and deoxynucleoside triphosphates (NTPs and dNTPs) by substitution at a beta-phosphorus to yield a nucleotide monophosphate (NMP) and inorganic pyrophosphate (PPi). This enzyme requires two divalent cations for activity; one coordinates the phosphoryl groups of the NTP/dNTP substrate, and the other coordinates to the enzyme. It also contains the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as metal binding and catalytic site. MutT pyrophosphohydrolase is important in preventing errors in DNA replication by hydrolyzing mutagenic nucleotides such as 8-oxo-dGTP (a product of oxidative damage), which can mispair with template adenine during DNA replication, to guanine nucleotides.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   8 ICEHEGHILFVRKARSK-----WALPGGKVERDERPVGAAERELEEETGLNVDGLLYLQELK-ARDTLH---HVFEASVV 78
Cdd:cd03425    7 IIVDDGRVLIAQRPEGKhlaglWEFPGGKVEPGETPEQALVRELREELGIEVEVGEPLGTVEhDYPDFHvrlHVYLCTLW 86

                         90       100       110
                 ....*....|....*....|....*....|....*..
gi 814584484  79 N-IAQARPCNEIidcRWHAYSAMDELDTTDTTRHIVK 114
Cdd:cd03425   87 SgEPQLLEHQEL---RWVTPEELDDLDWLPADIPIVE 120

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 814584484  12 EGHILFVR--KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLY--LQE 62
Cdd:cd18874   13 DGKVLLVRshKWNDLYGIPGGKVEWGETLEEALKREVKEETGLDITDIRFilVQE 67

MutT homolog-1 and similar proteins; MutT homolog-1 (MTH1), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 1/Nudt1, is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 814584484  12 EGHILFVRKARSK----WALPGGKVERDERPVGAAERELEEETGLNV 54
Cdd:cd04679   12 DGRLLLVLRLRAPeaghWGLPGGKVDWLETVEDAVRREILEELGLEI 58

8-oxo-dGTP diphosphatase MutT;

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 814584484   1 MK---IRATVICEHEGHILFVRKAR-----SKWALPGGKVERDERPVGAAERELEEETGLNV 54
Cdd:PRK10776   1 MKklqIAVGIIRNPNNEIFITRRAAdahmaGKWEFPGGKIEAGETPEQALIRELQEEVGITV 62

diadenosine tetraphosphate; Diadenosine tetraphosphate (Ap4A; EC 3.6.1.17), also called NUDIX (nucleoside diphosphate-linked moiety X)) motif 2/Nudt2, is a member of the NUDIX hydrolase superfamily. Ap4A hydrolases are well represented in a variety of prokaryotic and eukaryotic organisms. Phylogenetic analysis reveals two distinct subgroups where plant enzymes fall into one subfamily and fungi/animals/archaea enzymes, represented by this subfamily, fall into another. Bacterial enzymes are found in both subfamilies. Ap4A is a potential by-product of aminoacyl tRNA synthesis, and accumulation of Ap4A has been implicated in a range of biological events, such as DNA replication, cellular differentiation, heat shock, metabolic stress, and apoptosis. Ap4A hydrolase cleaves Ap4A asymmetrically into ATP and AMP. It is important in the invasive properties of bacteria and thus presents a potential target for inhibition of such invasive bacteria. Besides the signature NUDIX motif (G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val) that functions as a metal binding and catalytic site, and a required divalent cation, Ap4A hydrolase is structurally similar to the other members of the NUDIX hydrolase superfamily with some degree of variation. Several regions in the sequences are poorly defined and substrate and metal binding sites are only predicted based on kinetic studies.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   8 ICEHEGHILFVRKARSK-WALPGGKVERDERPVGAAERELEEETGLNVDGLLYlqelKARDTLHHVFEASV---VN--IA 81
Cdd:cd03428   12 RDNGEIEFLLLQHSYGGhWDFPKGHVEPGESELETALRETKEETGLTVDDLPP----GFRETLTYSFKEGVektVVyfLA 87

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*
gi 814584484  82 QARPC------NEIIDCRWHAYSAMDELDTTDTTRHIVKSFLRRL 120
Cdd:cd03428   88 ELTPDvevklsEEHQDYKWLPYEEALQLLTYENIKELLKEANEYL 132

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 814584484   7 VICEHEGHILFVRKARSKWA---LPGGKVERDERPVGAAERELEEETGL 52
Cdd:cd04663    7 VTRGRNRELLVFEHPDFPEAglqVPKGTVEPGESPEEAALRELAEETGL 55

ADP-ribose pyrophosphatase; ADP-ribose pyrophosphatase (ADPRase; EC 3.6.1.13) catalyzes the hydrolysis of ADP-ribose to AMP and ribose-5-P. Like other members of the NUDIX hydrolase superfamily of enzymes, it is thought to require a divalent cation, such as Mg2+, for its activity. It also contains a 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. In humans, there are four distinct ADPRase activities, three putative cytosolic (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). ADPRase-m is also known as NUDT9. It can be distinugished from the cytosolic ADPRase by a N-terminal target sequence unique to mitochondrial ADPRase. NUDT9 functions as a monomer.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   3 IRATVIceHEGHILFVRKARSKWALPGGKVERDERPVGAAERELEEETGLNV--DGLLYLQelkarDTLHHVFEASVVNI 80
Cdd:cd18889    5 TRAAIF--KDDKILLVQEKDGRWSLPGGWVDVNQSIKENTIKEAKEEAGLDVepKRIIAVL-----DRNKHNKPPYAYGI 77

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|.
gi 814584484  81 AQA-----------RPCNEIIDCRWHAYSAMDELDTTDTTR 110
Cdd:cd18889   78 YKIfvlcellggefQPNIETIESGYFSLDELPPLSEEKNTK 118

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 814584484   7 VICEHEGHILFVRKARS-----KWALPGGKVERDERPVGAAERELEEETGLNVDGllylQELKARDTLHHV 72
Cdd:cd04683    5 LLLVRGDEVLLLRRANTgyddgWWHLPAGHVEAGETVRAAAVREAKEELGVEIDP----EDLRLVHTMHRR 71

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 814584484   4 RATVICEHEGHILFVRKARSK---WALPGGKVERDERPVGAAERELEEETGLNV-DGLLYLQELKARDTLHHVFEASVV 78
Cdd:cd04669    2 RAVLVIYDDDKLLLIRRTKPGeeyYVFPGGGIEPGETPEEAALREAVEELGLDVaVTLITLILRVLNDGTQHYFLARVI 80

dihydroneopterin hydrolase; DHNTP pyrophosphatase (DHNTPase) catalyzes the hydrolysis of dihydroneopterin triphosphate (DHNTP) to dihydroneopterin monophosphate (DHNMP) and pyrophosphate,the second step in the pterin branch of the folate synthesis pathway in bacteria. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484  30 GKVERDERPVGAAERELEEETGLNVDGLLYLQEL-------------KARDTLHHVFEASVVNIAQARPCNEIIDCRWHA 96
Cdd:cd04664   33 GGIEDGETPWQAALRELKEETGLDPLELQLIDLNvsnfyeifddwrpGVTVNTEHVFAVEVPEEQPIRLSPEHTDYRWLP 112

                         90       100
                 ....*....|....*....|
gi 814584484  97 YSAMDELDTTDTTRHIVKSF 116
Cdd:cd04664  113 YEEAAELLFWPSNREALREL 132

MutT homolog-1 and similar proteins; MutT homolog-1 (MTH1), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 1/Nudt1, is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 814584484   3 IRATVIceHEGHILFVR-KARSKWALPGGKVERDERPVGAAERELEEETGLNVDGLLYL----QELKARDTLH----HVF 73
Cdd:cd18883    3 ARGVII--SDEHLLLARvKGDDKTFLPGGHIEIGESAEIALVRELREELGLSCKVGRYLgaveNQWQDKEVIHvelnHLF 80

                 ....
gi 814584484  74 EASV 77
Cdd:cd18883   81 EVEL 84

translation initiation factor IF-2B alpha subunit; Eukaryotic translation initiation factor 2B subunit alpha (EIF2B1) is one of five subunits of eukaryotic translation initiation factor 2B (EIF2B), a GTP exchange factor for eukaryotic initiation factor 2 and an essential regulator for protein synthesis. Mutations in this gene and the genes encoding other EIF2B subunits have been associated with leukoencephalopathy with vanishing white matter. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.