Anaerobic 5-Hydroxybenzimidazole Formation from Aminoimidazole Ribotide: An Unanticipated Intersection of Thiamin and Vitamin B<sub>12</sub> Biosynthesis
作者:Angad P. Mehta、Sameh H. Abdelwahed、Michael K. Fenwick、Amrita B. Hazra、Michiko E. Taga、Yang Zhang、Steven E. Ealick、Tadhg P. Begley
DOI:10.1021/jacs.5b03576
日期:2015.8.26
(thiC) revealed a paralogue of thiC (bzaF) clustered with anaerobic vitamin B12 biosynthetic genes. Here we demonstrate that BzaF is a radical S-adenosylmethionine enzyme that catalyzes the remarkable conversion of aminoimidazole ribotide (AIR) to 5-hydroxybenzimidazole (5-HBI). We identify the origin of key product atoms and propose a reaction mechanism. These studies represent the first step in solving
A “Radical Dance” in Thiamin Biosynthesis: Mechanistic Analysis of the Bacterial Hydroxymethylpyrimidine Phosphate Synthase
作者:Abhishek Chatterjee、Amrita B. Hazra、Sameh Abdelwahed、David G. Hilmey、Tadhg P. Begley
DOI:10.1002/anie.201003419
日期:2010.11.8
Tricky things with ThiC: Hydroxymethylpyrimidinephosphate (HMP‐P) synthase (ThiC) catalyzes one of the most complex rearrangement reactions in primary metabolism. Deuteration experiments show that under reducing conditions, in the presence of aminoimidazole ribonucleotide, the 5′‐deoxyadenosyl radical generated at the active site of ThiC reacts directly with the substrate and performs two iterative