Saccharomyces cerevisiae THI4p is a suicide thiamine thiazole synthase.
Thiamine pyrophosphate 1 is an essential cofactor in all living systems. Its biosynthesis involves the separate syntheses of the pyrimidine 2 and thiazole 3 precursors, which are then coupled. Two biosynthetic routes to the thiamine thiazole have been identified. In prokaryotes, five enzymes act on three substrates to produce the thiazole via a complex oxidative condensation reaction, the mechanistic details of which are now well established. In contrast, only one gene product is involved in thiazole biosynthesis in eukaryotes (THI4p in Saccharomyces cerevisiae). Here we report the preparation of fully active recombinant wild-type THI4p, the identification of an iron-dependent sulphide transfer reaction from a conserved cysteine residue of the protein to a reaction intermediate and the demonstration that THI4p is a suicide enzyme undergoing only a single turnover.
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Abhishek
A
Chatterjee
N Dinuka
ND
Abeydeera
Shridhar
S
Bale
Pei-Jing
PJ
Pai
Pieter C
PC
Dorrestein
David H
DH
Russell
Steven E
SE
Ealick
Tadhg P
TP
Begley
D000595:Amino Acid Sequence; D055162:Biocatalysis; D019759:Carbon-Nitrogen Lyases / Q000737:chemistry / Q000378:metabolism*; D017124:Conserved Sequence; D003545:Cysteine / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D011994:Recombinant Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism; D013831:Thiamine / Q000378:metabolism*; D013835:Thiamine Pyrophosphate / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism*
D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D013440:Sulfides; C089358:THI4 protein, S cerevisiae; D013844:Thiazoles; D013455:Sulfur; D007501:Iron; D019759:Carbon-Nitrogen Lyases; D003545:Cysteine; D013835:Thiamine Pyrophosphate; D013831:Thiamine