vicinal oxygen chelate (VOC) family; The vicinal oxygen chelate (VOC) superfamily is composed of structurally related proteins with paired beta.alpha.beta.beta.beta motifs that provide a metal coordination environment with two or three open or readily accessible coordination sites to promote direct electrophilic participation of the metal ion in catalysis. VOC is found in a variety of structurally related metalloproteins, including the type I extradiol dioxygenases, glyoxalase I and a group of antibiotic resistance proteins. A bound metal ion is required for protein activities for the members of this superfamily. A variety of metal ions have been found in the catalytic centers of these proteins including Fe(II), Mn(II), Zn(II), Ni(II) and Mg(II). Type I extradiol dioxygenases catalyze the incorporation of both atoms of molecular oxygen into aromatic substrates, which results in the cleavage of aromatic rings. They are key enzymes in the degradation of aromatic compounds. Type I extradiol dioxygenases include class I and class II enzymes. Class I and II enzymes show sequence similarity; the two-domain class II enzymes evolved from a class I enzyme through gene duplication. Glyoxylase I catalyzes the glutathione-dependent inactivation of toxic methylglyoxal, requiring zinc or nickel ions for activity. The antibiotic resistance proteins in this family use a variety of mechanisms to block the function of antibiotics. Bleomycin resistance protein (BLMA) sequesters bleomycin's activity by directly binding to it. Whereas, three types of fosfomycin resistance proteins employ different mechanisms to render fosfomycin inactive by modifying the fosfomycin molecule. Although the proteins in this superfamily are functionally distinct, their structures are similar. The difference among the three dimensional structures of the three types of proteins in this superfamily is interesting from an evolutionary perspective. Both glyoxalase I and BLMA show domain swapping between subunits. However, there is no domain swapping for type 1 extradiol dioxygenases.

                         10        20
                 ....*....|....*....|
gi 446673499   5 IDHIGIAVRDIDSTIRFYEN 24
Cdd:cd07249    1 LDHIGIAVPDLDEALKFYED 20

Methylmalonyl-CoA epimerase (MMCE); MMCE, also called methylmalonyl-CoA racemase (EC 5.1.99.1) interconverts (2R)-methylmalonyl-CoA and (2S)-methylmalonyl-CoA. MMCE has been found in bacteria, archaea, and in animals. In eukaryotes, MMCE is an essential enzyme in a pathway that converts propionyl-CoA to succinyl-CoA, and is important in the breakdown of odd-chain length fatty acids, branched-chain amino acids, and other metabolites. In bacteria, MMCE participates in the reverse pathway for propionate fermentation, glyoxylate regeneration, and the biosynthesis of polyketide antibiotics. MMCE is closely related to glyoxalase I and type I extradiol dioxygenases.

                         10        20
                 ....*....|....*....|
gi 446673499   5 IDHIGIAVRDIDSTIRFYEN 24
Cdd:cd07249    1 LDHIGIAVPDLDEALKFYED 20

Glyoxalase/Bleomycin resistance protein/Dioxygenase superfamily;

                          10        20
                  ....*....|....*....|..
gi 446673499    4 TIDHIGIAVRDIDSTIRFYENC 25
Cdd:pfam00903   1 RIDHVALRVGDLEKSLDFYTDV 22

Methylmalonyl-CoA epimerase (MMCE); MMCE, also called methylmalonyl-CoA racemase (EC 5.1.99.1) interconverts (2R)-methylmalonyl-CoA and (2S)-methylmalonyl-CoA. MMCE has been found in bacteria, archaea, and in animals. In eukaryotes, MMCE is an essential enzyme in a pathway that converts propionyl-CoA to succinyl-CoA, and is important in the breakdown of odd-chain length fatty acids, branched-chain amino acids, and other metabolites. In bacteria, MMCE participates in the reverse pathway for propionate fermentation, glyoxylate regeneration, and the biosynthesis of polyketide antibiotics. MMCE is closely related to glyoxalase I and type I extradiol dioxygenases.

                         10        20
                 ....*....|....*....|
gi 446673499   5 IDHIGIAVRDIDSTIRFYEN 24
Cdd:cd07249    1 LDHIGIAVPDLDEALKFYED 20

4-hydroxyphenylpyruvate dioxygenase and related hemolysins [Amino acid transport and metabolism, General function prediction only];

                         10        20
                 ....*....|....*....|....*.
gi 446673499   1 MKKTIDHIGIAVR--DIDSTIRFYEN 24
Cdd:COG3185  143 GLTRIDHIGIAVPrgDLDEWVLFYED 168

Glyoxalase/Bleomycin resistance protein/Dioxygenase superfamily;

                          10        20
                  ....*....|....*....|..
gi 446673499    4 TIDHIGIAVRDIDSTIRFYENC 25
Cdd:pfam00903   1 RIDHVALRVGDLEKSLDFYTDV 22

Catechol-2,3-dioxygenase [Secondary metabolites biosynthesis, transport and catabolism];

                         10        20
                 ....*....|....*....|
gi 446673499   5 IDHIGIAVRDIDSTIRFYEN 24
Cdd:COG2514    4 LGHVTLRVRDLERSAAFYTD 23

vicinal oxygen chelate (VOC) family; The vicinal oxygen chelate (VOC) superfamily is composed of structurally related proteins with paired beta.alpha.beta.beta.beta motifs that provide a metal coordination environment with two or three open or readily accessible coordination sites to promote direct electrophilic participation of the metal ion in catalysis. VOC is found in a variety of structurally related metalloproteins, including the type I extradiol dioxygenases, glyoxalase I and a group of antibiotic resistance proteins. A bound metal ion is required for protein activities for the members of this superfamily. A variety of metal ions have been found in the catalytic centers of these proteins including Fe(II), Mn(II), Zn(II), Ni(II) and Mg(II). Type I extradiol dioxygenases catalyze the incorporation of both atoms of molecular oxygen into aromatic substrates, which results in the cleavage of aromatic rings. They are key enzymes in the degradation of aromatic compounds. Type I extradiol dioxygenases include class I and class II enzymes. Class I and II enzymes show sequence similarity; the two-domain class II enzymes evolved from a class I enzyme through gene duplication. Glyoxylase I catalyzes the glutathione-dependent inactivation of toxic methylglyoxal, requiring zinc or nickel ions for activity. The antibiotic resistance proteins in this family use a variety of mechanisms to block the function of antibiotics. Bleomycin resistance protein (BLMA) sequesters bleomycin's activity by directly binding to it. Whereas, three types of fosfomycin resistance proteins employ different mechanisms to render fosfomycin inactive by modifying the fosfomycin molecule. Although the proteins in this superfamily are functionally distinct, their structures are similar. The difference among the three dimensional structures of the three types of proteins in this superfamily is interesting from an evolutionary perspective. Both glyoxalase I and BLMA show domain swapping between subunits. However, there is no domain swapping for type 1 extradiol dioxygenases.

                         10
                 ....*....|....*...
gi 446673499   7 HIGIAVRDIDSTIRFYEN 24
Cdd:cd06587    1 HVALRVPDLDASVAFYEE 18

methylmalonyl-CoA epimerase; Members of this protein family are the enzyme methylmalonyl-CoA epimerase (EC 5.1.99.1), also called methylmalonyl-CoA racemase. This enzyme converts (2R)-methylmalonyl-CoA to (2S)-methylmalonyl-CoA, which is then a substrate for methylmalonyl-CoA mutase (TIGR00642). It is known in bacteria, archaea, and as a mitochondrial protein in animals. It is closely related to lactoylglutathione lyase (TIGR00068), which is also called glyoxylase I, and is also a homodimer.

                          10        20
                  ....*....|....*....|
gi 446673499    5 IDHIGIAVRDIDSTIRFYEN 24
Cdd:TIGR03081   2 IDHVGIAVPDLEEAAKFYED 21