Nitrilase superfamily, including nitrile- or amide-hydrolyzing enzymes and amide-condensing enzymes; This superfamily (also known as the C-N hydrolase superfamily) contains hydrolases that break carbon-nitrogen bonds; it includes nitrilases, cyanide dihydratases, aliphatic amidases, N-terminal amidases, beta-ureidopropionases, biotinidases, pantotheinase, N-carbamyl-D-amino acid amidohydrolases, the glutaminase domain of glutamine-dependent NAD+ synthetase, apolipoprotein N-acyltransferases, and N-carbamoylputrescine amidohydrolases, among others. These enzymes depend on a Glu-Lys-Cys catalytic triad, and work through a thiol acylenzyme intermediate. Members of this superfamily generally form homomeric complexes, the basic building block of which is a homodimer. These oligomers include dimers, tetramers, hexamers, octamers, tetradecamers, octadecamers, as well as variable length helical arrangements and homo-oligomeric spirals. These proteins have roles in vitamin and co-enzyme metabolism, in detoxifying small molecules, in the synthesis of signaling molecules, and in the post-translational modification of proteins. They are used industrially, as biocatalysts in the fine chemical and pharmaceutical industry, in cyanide remediation, and in the treatment of toxic effluent. This superfamily has been classified previously in the literature, based on global and structure-based sequence analysis, into thirteen different enzyme classes (referred to as 1-13). This hierarchy includes those thirteen classes and a few additional subfamilies. A putative distant relative, the plasmid-borne TraB family, has not been included in the hierarchy.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1669946503  38 YVAAVYEHPSILSLNPlalisrqEALELMNQNLDIYEQQVMTAAQKDVQIIVFPEDGIHGFNFTRTSIYPFLDFMPsPQV 117
Cdd:cd07567     1 YIAAVVEHHPILSPDP-------DALQIMEKNLDIYEEIIKSAAKQGADIIVFPEDGLTGFIFTRFVIYPFLEDVP-DPE 72

                          90
                  ....*....|....*.
gi 1669946503 118 VRWNPCLEPHRFNDTE 133
Cdd:cd07567    73 VNWNPCLDPDRFDYTE 88

biotinidase and vanins (class 4 nitrilases); These secondary amidases participate in vitamin recycling. Biotinidase (EC 3.5.1.12) has both a hydrolase and a transferase activity. It hydrolyzes free biocytin or small biotinyl-peptides produced during the proteolytic degradation of biotin-dependent carboxylases, to release free biotin (vitamin H), and it can transfer biotin to acceptor molecules such as histones. Biotinidase deficiency in humans is an autosomal recessive disorder characterized by neurological and cutaneous symptoms. This subgroup includes the three human vanins, vanin1-3. Vanins are ectoenzymes, Vanin-1, and -2 are membrane associated, vanin-3 is secreted. They are pantotheinases (EC 3.5.1.92, pantetheine hydrolase), which convert pantetheine, to pantothenic acid (vitamin B5) and cysteamine (2-aminoethanethiol, a potent anti-oxidant). They are potential targets for therapeutic intervention in inflammatory disorders. Vanin-1 deficient mice lacking free cysteamine are less susceptible to intestinal inflammation, and expression of vanin-1 and -3 is induced as part of the inflammatory-regenerative differentiation program of human epidermis. This subgroup belongs to a larger nitrilase superfamily comprised of nitrile- or amide-hydrolyzing enzymes and amide-condensing enzymes, which depend on a Glu-Lys-Cys catalytic triad. This superfamily has been classified in the literature based on global and structure based sequence analysis into thirteen different enzyme classes (referred to as 1-13), this subgroup corresponds to class 4. Members of this superfamily generally form homomeric complexes, the basic building block of which is a homodimer.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1669946503  38 YVAAVYEHPSILSLNPlalisrqEALELMNQNLDIYEQQVMTAAQKDVQIIVFPEDGIHGFNFTRTSIYPFLDFMPsPQV 117
Cdd:cd07567     1 YIAAVVEHHPILSPDP-------DALQIMEKNLDIYEEIIKSAAKQGADIIVFPEDGLTGFIFTRFVIYPFLEDVP-DPE 72

                          90
                  ....*....|....*.
gi 1669946503 118 VRWNPCLEPHRFNDTE 133
Cdd:cd07567    73 VNWNPCLDPDRFDYTE 88

biotinidase and vanins (class 4 nitrilases); These secondary amidases participate in vitamin recycling. Biotinidase (EC 3.5.1.12) has both a hydrolase and a transferase activity. It hydrolyzes free biocytin or small biotinyl-peptides produced during the proteolytic degradation of biotin-dependent carboxylases, to release free biotin (vitamin H), and it can transfer biotin to acceptor molecules such as histones. Biotinidase deficiency in humans is an autosomal recessive disorder characterized by neurological and cutaneous symptoms. This subgroup includes the three human vanins, vanin1-3. Vanins are ectoenzymes, Vanin-1, and -2 are membrane associated, vanin-3 is secreted. They are pantotheinases (EC 3.5.1.92, pantetheine hydrolase), which convert pantetheine, to pantothenic acid (vitamin B5) and cysteamine (2-aminoethanethiol, a potent anti-oxidant). They are potential targets for therapeutic intervention in inflammatory disorders. Vanin-1 deficient mice lacking free cysteamine are less susceptible to intestinal inflammation, and expression of vanin-1 and -3 is induced as part of the inflammatory-regenerative differentiation program of human epidermis. This subgroup belongs to a larger nitrilase superfamily comprised of nitrile- or amide-hydrolyzing enzymes and amide-condensing enzymes, which depend on a Glu-Lys-Cys catalytic triad. This superfamily has been classified in the literature based on global and structure based sequence analysis into thirteen different enzyme classes (referred to as 1-13), this subgroup corresponds to class 4. Members of this superfamily generally form homomeric complexes, the basic building block of which is a homodimer.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1669946503  38 YVAAVYEHPSILSLNPlalisrqEALELMNQNLDIYEQQVMTAAQKDVQIIVFPEDGIHGFNFTRTSIYPFLDFMPsPQV 117
Cdd:cd07567     1 YIAAVVEHHPILSPDP-------DALQIMEKNLDIYEEIIKSAAKQGADIIVFPEDGLTGFIFTRFVIYPFLEDVP-DPE 72

                          90
                  ....*....|....*.
gi 1669946503 118 VRWNPCLEPHRFNDTE 133
Cdd:cd07567    73 VNWNPCLDPDRFDYTE 88