Saccharomyces cerevisiae THI4p is a suicide thiamine thiazole synthase.
Saccharomyces cerevisiae THI4p is a suicide thiamine thiazole synthase.
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DOI：
10.1038/nature10503
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发表时间：
2011-10-26
期刊：
影响因子：
64.8
通讯作者：
Begley, Tadhg P.
中科院分区：
文献类型：
--
作者：
Chatterjee, Abhishek;Abeydeera, N. Dinuka;Bale, Shridhar;Pai, Pei-Jing;Dorrestein, Pieter C.;Russell, David H.;Ealick, Steven E.;Begley, Tadhg P.
焦磷酸硫胺1（图1A）是所有生命系统中必不可少的辅助因子。它的生物合成涉及嘧啶2和噻唑3前体的单独合成，然后它们被偶联。已经确定了两种生物合成硫胺素噻唑的途径。在原核生物中，五种酶作用于三种底物，通过复杂的氧化缩合反应产生噻唑，其机理细节现已确定。相比之下，真核生物中只有一个基因产物参与噻唑的生物合成（酿酒酵母菌中的THI4p）。鉴定了三种腺苷化代谢物（图1B中的结构5、12和17），并与THI4p共纯化，提供了该蛋白催化的反应途径的三个分子快照。此外，还鉴定出两个部分活性突变体（C204A和H200N），它们催化NAD（烟酰胺腺嘌呤二核苷酸）6和甘氨酸9转化为高级中间体12。图1B概述了与这些观察结果一致的噻唑形成机制。然而，噻唑硫的来源仍然难以捉摸，这使我们无法破译导致腺苷化噻唑5的后续步骤。在这里，我们报道了完全活性重组野生型THI4p的制备，鉴定了从蛋白质到反应中间体的铁依赖硫化物转移反应，并证明THI4p是一种仅经历一次翻转的自杀酶。
Thiamin pyrophosphate 1 (Figure 1A) 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 thiamin 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). Identification of three adenylated metabolites (structures 5, 12 and 17 in Figure 1B), co-purifying with THI4p, provided three molecular snapshots of the reaction pathway catalyzed by this protein. In addition, two partially active mutants were identified (C204A and H200N), which catalyzed the conversion of NAD (nicotinamide adenine dinucleotide) 6 and glycine 9 to an advanced intermediate 12. A mechanism for thiazole formation, consistent with these observations, is outlined in Figure 1B. However, the source of the thiazole sulfur remained elusive, precluding us from deciphering the subsequent steps leading to the adenylated thiazole 5. Here we report the preparation of fully active recombinant wild type THI4p, the identification of an iron-dependent sulfide transfer reaction from the protein to a reaction intermediate and the demonstration that THI4p is a suicidal enzyme undergoing only a single turnover.
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影响因子：
16.6
作者：
Jurgenson CT;Begley TP;Ealick SE
通讯作者：
Ealick SE
DOI：
10.1073/pnas.82.9.2688
发表时间：
1985-01-01
影响因子：
11.1
作者：
DEMPLE, B;SEDGWICK, B;LINDAHL, T
通讯作者：
LINDAHL, T
影响因子：
15
作者：
Hazra, Amrita B.;Han, Ying;Chatterjee, Abhishek;Zhang, Yang;Lai, Rung-Yi;Ealick, Steven E.;Begley, Tadhg P.
通讯作者：
Begley, Tadhg P.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
15
作者：
Chatterjee, Abhishek;Jurgenson, Christopher T.;Begley, Tadhg P.
通讯作者：
Begley, Tadhg P.