Eser Bekir E, Zhang Xuan, Chanani Prem K, Begley Tadhg P, Ealick Steven E
Department of Medical Biochemistry, Emine-Bahaeddin Nakıboglu School of Medicine, Zirve University , Gaziantep 27260, Turkey.
Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
J Am Chem Soc. 2016 Mar 23;138(11):3639-42. doi: 10.1021/jacs.6b00445. Epub 2016 Mar 11.
Bacteria and yeast utilize different strategies for sulfur incorporation in the biosynthesis of the thiamin thiazole. Bacteria use thiocarboxylated proteins. In contrast, Saccharomyces cerevisiae thiazole synthase (THI4p) uses an active site cysteine as the sulfide source and is inactivated after a single turnover. Here, we demonstrate that the Thi4 ortholog from Methanococcus jannaschii uses exogenous sulfide and is catalytic. Structural and biochemical studies on this enzyme elucidate the mechanistic details of the sulfide transfer reactions.
细菌和酵母在硫胺噻唑生物合成中采用不同的硫掺入策略。细菌使用硫代羧化蛋白。相比之下，酿酒酵母噻唑合酶（THI4p）使用活性位点半胱氨酸作为硫化物来源，并且在单次周转后失活。在这里，我们证明来自詹氏甲烷球菌的Thi4直系同源物使用外源硫化物并且具有催化活性。对该酶的结构和生化研究阐明了硫化物转移反应的机制细节。
