Biosynthesis of Histidine.
Biosynthesis of Histidine.
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DOI：
10.1128/ecosalplus.3.6.1.9
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发表时间：
2009-08
期刊：
影响因子：
--
通讯作者：
Ramos-Montañez S
中科院分区：
文献类型：
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作者：
Winkler ME;Ramos-Montañez S
组氨酸在大肠杆菌和鼠伤寒沙门氏菌中的生物合成是研究生物合成途径中中间产物的流动与编码催化途径中各步骤的酶的基因控制之间关系的重要模型系统。本文提供了一个全面的审查组氨酸生物合成途径和酶，包括调节中间体的流量通过的途径和机制，调节组氨酸生物合成酶的量。此外，本文还综述了组氨酸生物合成操纵子的结构和调控，包括转录加工、Rho因子依赖的“经典”极性以及组氨酸操纵子衰减控制的现有模型。重点放在最近取得进展的领域。值得注意的是，大多数催化组氨酸生物合成的酶最近已经结晶，并且它们的结构已经确定。许多组氨酸生物合成中间体是不稳定的，并且组氨酸生物合成酶催化一些化学上不寻常的反应。因此，这些研究导致了对途径本身的相当多的机理性见解，并提供了对几个基本过程的深入生化理解，如反馈控制，变构相互作用和代谢物通道。近年来，在pp（p）Gpp刺激hisoperon转录的机制、RNA聚合酶引起转录暂停的分子基础和途径进化等方面也取得了相当大的进展。随着新的基因组学、代谢组学、蛋白质组学和结构学方法在组氨酸生物合成途径和其他细菌中控制组氨酸生物合成基因的机制研究中的融合，这些领域的进展将继续下去。
The biosynthesis of histidine inEscherichia coliandSalmonella typhimuriumhas been an important model system for the study of relationships between the flow of intermediates through a biosynthetic pathway and the control of the genes encoding the enzymes that catalyze the steps in a pathway. This article provides a comprehensive review of the histidine biosynthetic pathway and enzymes, including regulation of the flow of intermediates through the pathway and mechanisms that regulate the amounts of the histidine biosynthetic enzymes. In addition, this article reviews the structure and regulation of the histidine (his) biosynthetic operon, including transcript processing, Rho-factor-dependent “classical” polarity, and the current model ofhisoperon attenuation control. Emphasis is placed on areas of recent progress. Notably, most of the enzymes that catalyze histidine biosynthesis have recently been crystallized, and their structures have been determined. Many of the histidine biosynthetic intermediates are unstable, and the histidine biosynthetic enzymes catalyze some chemically unusual reactions. Therefore, these studies have led to considerable mechanistic insight into the pathway itself and have provided deep biochemical understanding of several fundamental processes, such as feedback control, allosteric interactions, and metabolite channeling. Considerable recent progress has also been made on aspects ofhisoperon regulation, including the mechanism of pp(p)Gpp stimulation ofhisoperon transcription, the molecular basis for transcriptional pausing by RNA polymerase, and pathway evolution. The progress in these areas will continue as sophisticated new genomic, metabolomic, proteomic, and structural approaches converge in studies of the histidine biosynthetic pathway and mechanisms of control ofhisbiosynthetic genes in other bacterial species.