Biosynthesis of the thiazole moiety of thiamin pyrophosphate (vitamin B1).
While most of the proteins required for the biosynthesis of thiamin pyrophosphate have been known for more than a decade, the reconstitution of this biosynthesis in a defined biochemical system has been difficult due to the novelty of the chemistry involved. Here we demonstrate the first successful enzymatic synthesis of the thiazole moiety of thiamin from glycine, cysteine, and deoxy-D-xylulose-5-phosphate using overexpressed Bacillus subtilis ThiF, ThiS, ThiO, ThiG, and a NifS-like protein. This has facilitated the identification of the biochemical function of each of the proteins involved: ThiF catalyzes the adenylation of ThiS; NifS catalyzes the transfer of sulfur from cysteine to the acyl adenylate of ThiS; ThiO catalyzes the oxidation of glycine to the corresponding imine; and ThiG catalyzes the formation of the thiazole phosphate ring. The complex oxidative cyclization reaction involved in the biosynthesis of the thiamin thiazole has been greatly simplified by replacing ThiF, ThiS, ThiO, and NifS with defined biosynthetic intermediates in a reaction where ThiG is the only required enzyme.
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Joo-Heon
JH
Park
Pieter C
PC
Dorrestein
Huili
H
Zhai
Cynthia
C
Kinsland
Fred W
FW
McLafferty
Tadhg P
TP
Begley
D001412:Bacillus subtilis / Q000235:genetics; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D021241:Spectrometry, Mass, Electrospray Ionization; D013831:Thiamine / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
D013831:Thiamine