title: Vitamin B6 enzymes participating in selenium amino acid metabolism.
abstract: Various vitamin B6 enzymes play important roles in mammalian and microbial metabolism of selenium amino acids. Selenocysteine is synthesized from selenohomocysteine by catalysis of cystathionine beta-synthase and cystathionine gamma-lyase, which both require pyridoxal phosphate. Selenocysteine beta-lyase, a new B6-enzyme, exclusively catalyzes beta-elimination of selenocysteine, and occurs in mammalian systems and bacteria. Methionine gamma-lyase, cysteine desulfurase, cysteine sulfinate desulfinase, and D-selenocystine alpha,beta-lyase, which are B6-enzymes, act on cysteine, cysteine sulfinate, D-cystine, and their derivatives, and their selenium counterparts indiscriminately. Their reaction mechanisms are comparatively described.
authors.affiliation: Department of Biotechnology, Faculty of Engineering, Kansai University, Suita, Osaka-Fu, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Soda
authors.forename: T
authors.initials: T
authors.lastname: Oikawa
authors.forename: N
authors.initials: N
authors.lastname: Esaki
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D008190:Lyases / Q000378:metabolism; D008322:Mammals; D008956:Models, Chemical; D016566:Organoselenium Compounds / Q000378:metabolism*; D011736:Pyridoxine / Q000378:metabolism*; D017279:Selenocysteine / Q000378:metabolism* / Q000031:analogs & derivatives
chemical_list: D016566:Organoselenium Compounds; D017279:Selenocysteine; D008190:Lyases; D003541:Cystathionine beta-Synthase; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase; C108137:cysteine sulfinate desulfinase; D003542:Cystathionine gamma-Lyase; C021558:L-methionine gamma-lyase; C054740:D-selenocystine alpha, beta-lyase; D003545:Cysteine; D011736:Pyridoxine; C002979:selenomethylselenocysteine