MutT homolog 2; MutT Homolog 2 (MTH2; EC 3.6.1.9), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 15/Nudt15, may catalyze the hydrolysis of nucleoside diphosphates, triphosphates including dGTP, dTTP, dCTP, their oxidized forms like 8-oxo-dGTP, and prodrug thiopurine derivatives 6-thio-dGTP and 6-thio-GTP. MTH2 may also play a role in DNA synthesis and cell cycle progression by stabilizing PCNA. 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 754169469  24 KHPRCVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKENYHYVTILMKGEVDv 103
Cdd:cd04678   11 NDDGKVLLGRRKGSHGAGTWALPGGHLEFGESFEECAAREVLEETGLEIRNVRFLTVTNDVFEEEGKHYVTIFVLAEVD- 89

                         90
                 ....*....|....*.
gi 754169469 104 tHDSEPKNVEPEKNES 119
Cdd:cd04678   90 -DGEPEENMEPDKCEG 104

MutT homolog 2; MutT Homolog 2 (MTH2; EC 3.6.1.9), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 15/Nudt15, may catalyze the hydrolysis of nucleoside diphosphates, triphosphates including dGTP, dTTP, dCTP, their oxidized forms like 8-oxo-dGTP, and prodrug thiopurine derivatives 6-thio-dGTP and 6-thio-GTP. MTH2 may also play a role in DNA synthesis and cell cycle progression by stabilizing PCNA. 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 754169469  24 KHPRCVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKENYHYVTILMKGEVDv 103
Cdd:cd04678   11 NDDGKVLLGRRKGSHGAGTWALPGGHLEFGESFEECAAREVLEETGLEIRNVRFLTVTNDVFEEEGKHYVTIFVLAEVD- 89

                         90
                 ....*....|....*.
gi 754169469 104 tHDSEPKNVEPEKNES 119
Cdd:cd04678   90 -DGEPEENMEPDKCEG 104

ADP-ribose pyrophosphatase YjhB, NUDIX family [Nucleotide transport and metabolism];

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEkenYHYVTILMKGEV 101
Cdd:COG1051   20 VLLVRRADEPGKGLWALPGGKVEPGETPEEAALRELREETGLEVEVLELLGVFDHPDR---GHVVSVAFLAEV 89

MutT homolog 2; MutT Homolog 2 (MTH2; EC 3.6.1.9), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 15/Nudt15, may catalyze the hydrolysis of nucleoside diphosphates, triphosphates including dGTP, dTTP, dCTP, their oxidized forms like 8-oxo-dGTP, and prodrug thiopurine derivatives 6-thio-dGTP and 6-thio-GTP. MTH2 may also play a role in DNA synthesis and cell cycle progression by stabilizing PCNA. 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 754169469  24 KHPRCVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKENYHYVTILMKGEVDv 103
Cdd:cd04678   11 NDDGKVLLGRRKGSHGAGTWALPGGHLEFGESFEECAAREVLEETGLEIRNVRFLTVTNDVFEEEGKHYVTIFVLAEVD- 89

                         90
                 ....*....|....*.
gi 754169469 104 tHDSEPKNVEPEKNES 119
Cdd:cd04678   90 -DGEPEENMEPDKCEG 104

ADP-ribose pyrophosphatase YjhB, NUDIX family [Nucleotide transport and metabolism];

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEkenYHYVTILMKGEV 101
Cdd:COG1051   20 VLLVRRADEPGKGLWALPGGKVEPGETPEEAALRELREETGLEVEVLELLGVFDHPDR---GHVVSVAFLAEV 89

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 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKENYHYVTILMKGEVDvthDSE 108
Cdd:cd04679   15 LLLVLRLRAPEAGHWGLPGGKVDWLETVEDAVRREILEELGLEIELTRLLCVVDQIDAADGEHWVAPVYLAEIF---SGE 91

                 ....*...
gi 754169469 109 PKNVEPEK 116
Cdd:cd04679   92 PRLMEPEK 99

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 754169469  23 CKHPRCVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKEN----YHYV 93
Cdd:cd04673    8 VFRDGRVLLVRRGNPPDAGLWSFPGGKVELGETLEDAALRELREETGLEAEVVGLLTVVDVIERDEAgrvrFHYV 82

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVN-SFIEKENYHYVTI 95
Cdd:cd03427   15 VLLGLKKRGFGAGKWNGFGGKVEPGETIEEAAVRELEEEAGLTATELEKVGRLKfEFPDDPEAMDVHV 82

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 754169469  29 VLLGKRKgSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVnSFIEKENYHYVTILMKGE 100
Cdd:cd18875   16 VLVLDRV-KKDWGGYTFPGGHVEPGESFVDSVIREVKEETGLTIKNPELCGIK-QWINPDGERYIVFLYKTD 85

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 754169469  45 LPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIEKENY---HYVTIlmkgevDVTHDSEPKNVEP 114
Cdd:cd18874   30 IPGGKVEWGETLEEALKREVKEETGLDITDIRFILVQESINSEEFHkpaHFVFV------DYLARTDSSEVVL 96

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
                 ....*....|....*....|....*....|....*....|....*....|
gi 754169469  28 CVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAalHLKNVHF 77
Cdd:cd18873   18 KVLLIKRKNEPFKGGWALPGGFVREDETLEDAARRELREET--GLKDIYL 65

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 754169469  27 RCVLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNSFIE---KENYHYVTILMKGEVDV 103
Cdd:cd04686   12 DKLLLIRKTRGPYQGRYDLPGGSQEFGESLEDALKREFAEETGMTVTSYDNLGVYDFFVPwsdKELGDVHHIGVFYDVEL 91

                         90
                 ....*....|....*.
gi 754169469 104 THDSEPKNVEPEKNES 119
Cdd:cd04686   92 LDNNISELLQFEGQDS 107

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 754169469  30 LLGKRKgsVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLK 73
Cdd:cd04690   14 LLLVRK--RGTDAFYLPGGKREPGETPLQALVRELKEELGLDLD 55

NADH pyrophosphatase; NADH pyrophosphatase, also known as NUDIX (nucleoside diphosphate linked moiety X)) motif 13/Nudt13, is thought to have NADH pyrophosphatase activity, be involved in NADH metabolic process and NADP catabolic process, catalyzing the cleavage of NADH into reduced nicotinamide mononucleotide (NMNH) and AMP, and located in mitochondrion. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity. Members of this family are also recognized by 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. A block of 8 conserved amino acids downstream of the NUDIX motif is thought to give NADH pyrophosphatase its specificity for NADH. NADH pyrophosphatase forms a dimer.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 754169469  29 VLLGKRKGSVGaGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFAS 79
Cdd:cd03429   15 ILLARQPRWPP-GRYSLLAGFVEPGETLEEAVRREVKEEVGLRVKNVRYVG 64

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 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVN 82
Cdd:cd04511   15 VLLCRRAIEPRKGYWTLPAGFMELGETTEQGAARETREEAGARVEIGSLYAVYS 68

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
                 ....*....|....*....|....*....|..
gi 754169469  39 GAGSFQLPGGHLEFGETWEECAQRETWEEAAL 70
Cdd:cd04674   27 GHGELALPGGYIEYGETWQEAAVRELREETGV 58

plant diadenosine tetraphosphate (Ap4A) hydrolase and similar proteins; Diadenosine tetraphosphate (Ap4A) hydrolase is a member of the NUDIX hydrolase superfamily. Members of this family are well represented in a variety of prokaryotic and eukaryotic organisms. Phylogenetic analysis reveals two distinct subgroups where plant enzymes fall into one group (represented by this subfamily) and fungi/animals/archaea enzymes 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 the inhibition of such invasive bacteria. Besides the signature NUDIX motif (G[X5]E[X7]REUXEEXGU where U is Ile, Leu, or Val), Ap4A hydrolase is structurally similar to the other members of the NUDIX hydrolase superfamily with some degree of variations. 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 754169469  29 VLLGKRKGSvgAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVnsfieKENYHY 92
Cdd:cd03671   17 VLVGRRIDV--PGAWQFPQGGIDEGEDPEEAALRELYEETGLSPEDVEIIAET-----PDWLTY 73

uncharacterized NUDIX hydrolase subfamily; Contains a crystal structure of the NUDIX hydrolase from Nitrosomonas europaea, which has an unknown function. 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
                 ....*....|....*....|....*....|..
gi 754169469  46 PGGHLEFGETWEECAQRETWEEAALHLKNVHF 77
Cdd:cd03675   29 PAGHLEPGESLLEAAIRETLEETGWEVEPTAL 60

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
                 ....*....|....*....|....*....|....*....|....*
gi 754169469  29 VLLGKRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLK 73
Cdd:cd04691   14 VLLVKRAYGPGKGRWTLPGGFVEEGETLDEAIVREVLEETGIDAK 58

NADH pyrophosphatase NudC, Nudix superfamily [Nucleotide transport and metabolism];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 754169469  29 VLLGkRKGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVH-FAS 79
Cdd:COG2816  171 ILLA-RQARWPPGRYSLLAGFVEPGETLEQAVRREVFEEVGVRVKNVRyVGS 221

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
                 ....*....|....*....|....*....|...
gi 754169469  45 LPGGHLEFGETWEECAQRETWEEAALHLKNVHF 77
Cdd:cd03424   33 LPAGKIDPGEDPEEAARRELEEETGYTAGDLEL 65

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 754169469  45 LPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVV-NSFIEKENYHyVTILMKGEVDVTHDsePKNVEPEKNES 119
Cdd:cd18883   26 LPGGHIEIGESAEIALVRELREELGLSCKVGRYLGAVeNQWQDKEVIH-VELNHLFEVELQDL--HTSDTPESQEP 98

diadenosine 5',5'''-P1,P6-hexaphosphate hydrolase type 2 and similar proteins; Diadenosine 5',5'''-P1,P6-hexaphosphate hydrolase type 2 (DIPP2), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 4; Nudt4, and other proteins including DIPP1/Nudt3, DIPP3a;APS2/Nudt10 and DIPP3beta;APS1/Nudt11. DIPP regulates the turnover of diphosphoinositol polyphosphates. The turnover of these high-energy diphosphoinositol polyphosphates represents a molecular switching activity with important regulatory consequences. Molecular switching by diphosphoinositol polyphosphates may contribute to regulating intracellular trafficking. Several alternatively spliced transcript variants have been described, but the full-length nature of some variants has not been determined. Isoforms DIPP2alpha and DIPP2beta are distinguishable from each other solely by DIPP2beta possessing one additional amino acid due to intron boundary skidding in alternate splicing. 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 754169469  45 LPGGHLEFGETWEECAQRETWEEAAlhlknvhfasVVNSFIEKE--NYHYVTILMKGEVDVTHDSEPKNVE------PEK 116
Cdd:cd04666   30 LPKGGPEKGETPAEAAAREAWEEAG----------VRGKVLKRPlgVYRYRKRLKGRGLPCRVHVFPLEVTeelddwPEK 99

                 ....*.
gi 754169469 117 NESKRI 122
Cdd:cd04666  100 HERKRR 105

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 754169469  45 LPGGHLEFGETWEECAQRETWEEAALHLKnVHFASVVNSFIEKENY-HYVTILMkgEVDVTHDSEPKNVEPEKN 117
Cdd:cd18880   29 LPGGGQEHGETLPEALKRECLEETGLDVE-VGDLLFVREYIGPNKPvHQVELFF--LCTLEGGELTLGSDPDLN 99

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 754169469  27 RCVLLGKRKGsvGAGSFQLPGGHLEFGETWEECAQRETWEEAALHLK 73
Cdd:cd04676   28 DGRILLQRKG--GLGLWSLPAGAIEPGEHPAEAVIREVREETGLLVK 72

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 754169469  29 VLLGKRKG-SVGAGSFQLPGGHLEFGETWEECAQRETWEEAAL 70
Cdd:cd18877   34 VLLQHRAWwTHQGGTWALPGGARDSGETPEAAALRETEEETGL 76

nucleoside diphosphate-linked moiety X)) motif 17; Nucleoside diphosphate-linked moiety X)) motif 17 (EC 3.6.1.-) encoded by the NUDT17 gene on chromosome 1q21.1 and encodes an enzyme thought to hydrolyse some nucleoside diphosphate derivatives. 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
                 ....*....|....*....|....*....|....*....|....*..
gi 754169469  28 CVLLGKR--KGSVGAGSFQLPGGHLEFGETWEECAQRETWEEAALHL 72
Cdd:cd04694   15 RVLLTRRakHMRTFPGVWVPPGGHVELGESLLEAGLRELQEETGLEV 61

uncharacterized NUDIX hydrolase subfamily; Contains a crystal structure of the NUDIX hydrolase from Enterococcus faecalis, which has an unknown function. 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
                 ....*....|....*....|....*....|
gi 754169469  38 VGAGSFQLPGGHLEFGETWEECAQRETWEE 67
Cdd:cd04684   34 TPNGGYFLPGGGIEPGETPEEALHREVLEE 63

DR1025 and similar proteins; DR1025 from Deinococcus radiodurans, a member of the NUDIX hydrolase superfamily, show nucleoside triphosphatase and dinucleoside polyphosphate pyrophosphatase activities. Like other enzymes belonging to this superfamily, it requires a divalent cation, in this case 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 and catalytic site. In general, 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 754169469  29 VLLGKRKGSVG----AGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHF 77
Cdd:cd04700   27 ILLVQEKGISGhpekAGLWHIPSGAVEDGENPQDAAVREACEETGLRVRLVKF 79

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
                 ....*....|....*....|....*..
gi 754169469  46 PGGHLEFGETWEECAQRETWEEAALHL 72
Cdd:cd04685   33 PGGGVEPGESPEQAAVRELREETGLRL 59

8-oxo-DGDP phosphatase; 8-oxo-DGDP phosphatase (8DGDPP; EC 3.6.1.55), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 18/Nudt18; 2-hydroxy-DADP phosphatase; 7,8-dihydro-8-oxoguanine phosphatase, hydrolyzes 8-oxo-7,8-dihydroguanine (8-oxo-Gua)-containing deoxyribo- and ribonucleoside diphosphates to the monophosphates. 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
                 ....*....|....*....|....*....|....
gi 754169469  40 AGSFQLPGGHLEFGETWEECAQRETWEEAALHLK 73
Cdd:cd04671   25 RGKWYLPAGRVEPGESIVEAAKREVKEETGLKCE 58

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
                 ....*....|....*....|....*....
gi 754169469  44 QLPGGHLEFGETWEECAQRETWEEAALHL 72
Cdd:cd04680   26 YLPGGGVDKGETAEEAARRELREEAGVVL 54

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 754169469  29 VLLGKRKGSvgaGSFQLPGGHLEFGETWEECAQRETWEEAALHLKNVHFASVVNS 83
Cdd:cd18879   32 VLLVRRADN---GRWTPVTGIVEPGEQPADAAVREVLEETGVDVEVERLASVGAS 83