Saraogi Ishu, Shan Shu-ou
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Biochim Biophys Acta. 2014 Aug;1843(8):1433-41. doi: 10.1016/j.bbamcr.2013.10.013. Epub 2013 Oct 24.
Co-translational protein targeting by the Signal Recognition Particle (SRP) is an essential cellular pathway that couples the synthesis of nascent proteins to their proper cellular localization. The bacterial SRP, which contains the minimal ribonucleoprotein core of this universally conserved targeting machine, has served as a paradigm for understanding the molecular basis of protein localization in all cells. In this review, we highlight recent biochemical and structural insights into the molecular mechanisms by which fundamental challenges faced by protein targeting machineries are met in the SRP pathway. Collectively, these studies elucidate how an essential SRP RNA and two regulatory GTPases in the SRP and SRP receptor (SR) enable this targeting machinery to recognize, sense and respond to its biological effectors, i.e. the cargo protein, the target membrane and the translocation machinery, thus driving efficient and faithful co-translational protein targeting. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
信号识别颗粒（SRP）介导的共翻译蛋白质靶向是一条重要的细胞途径，它将新生蛋白质的合成与其正确的细胞定位联系起来。细菌SRP包含这一普遍保守的靶向机制的最小核糖核蛋白核心，一直是理解所有细胞中蛋白质定位分子基础的范例。在这篇综述中，我们重点介绍了最近关于SRP途径中蛋白质靶向机制所面临的基本挑战是如何被应对的分子机制的生化和结构见解。总的来说，这些研究阐明了SRP中的一种必需SRP RNA和两种调节性GTP酶以及SRP受体（SR）如何使这种靶向机制识别、感知并响应其生物学效应物，即货物蛋白、靶膜和转运机制，从而驱动高效且准确的共翻译蛋白质靶向。本文是名为“细菌中的蛋白质运输与分泌”特刊的一部分。客座编辑：阿纳斯塔西奥斯·埃科诺莫和罗斯·达尔贝。
