title: Thiamin biosynthesis in prokaryotes.
abstract: Twelve genes involved in thiamin biosynthesis in prokaryotes have been identified and overexpressed. Of these, six are required for the thiazole biosynthesis (thiFSGH, thil, and dxs), one is involved in the pyrimidine biosynthesis (thiC), one is required for the linking of the thiazole and the pyrimidine (thiE), and four are kinase genes (thiD, thiM, thiL, and pdxK). The specific reactions catalyzed by ThiEF, Dxs, ThiDM, ThiL, and PdxK have been reconstituted in vitro and ThiS thiocarboxylate has been identified as the sulfur source. The X-ray structures of thiamin phosphate synthase and 5-hydroxyethyl-4-methylthiazole kinase have been completed. The genes coding for the thiamin transport system (thiBPQ) have also been identified. Remaining problems include the cloning and characterization of thiK (thiamin kinase) and the gene(s) involved in the regulation of thiamin biosynthesis. The specific reactions catalyzed by ThiC (pyrimidine formation), and ThiGH and ThiI (thiazole formation) have not yet been identified.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA. tpb2@cornell.edu
authors.forename: T P
authors.initials: TP
authors.lastname: Begley
authors.forename: D M
authors.initials: DM
authors.lastname: Downs
authors.forename: S E
authors.initials: SE
authors.lastname: Ealick
authors.forename: F W
authors.initials: FW
authors.lastname: McLafferty
authors.forename: A P
authors.initials: AP
authors.lastname: Van Loon
authors.forename: S
authors.initials: S
authors.lastname: Taylor
authors.forename: N
authors.initials: N
authors.lastname: Campobasso
authors.forename: H J
authors.initials: HJ
authors.lastname: Chiu
authors.forename: C
authors.initials: C
authors.lastname: Kinsland
authors.forename: J J
authors.initials: JJ
authors.lastname: Reddick
authors.forename: J
authors.initials: J
authors.lastname: Xi
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D011387:Prokaryotic Cells / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism; D013831:Thiamine / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D013831:Thiamine