来自美国哈佛大学的研究人员发现大肠杆菌内部的脂多糖分子在运输到细胞表面时需要多个ATP分子的水解能量,才能完成这种逆浓度梯度运输。

-2012年11月30日《科学》

中文翻译


【题目】大肠杆菌中细胞质ATP水解促进脂多糖转运通过细胞周质

【译文】每当大肠杆菌发生细胞分裂时,细胞表面需要组装成千上万的脂多糖(LPS)分子。LPS的生物合成需要7个必需的脂多糖转运(Lpt)蛋白,将LPS从内膜通过细胞周质运输到细胞表面。然而,尚没发现脂多糖的中间转运状态。本研究开发出一种方法:在体内直接观察到在LPS被转运过程中,中间态的LPS分子结合到Lpt蛋白上。在体外,单个LPS分子需要多轮三磷酸腺苷(ATP)水解作用的能量,才能沿着这些结合位点运动,这表明ATP常用来推动持续不断的LPS流通过“跨外膜桥”,在不连续的阶段来完成逆浓度梯度运输。

英文原稿


[Title]: Cytoplasmic ATP Hydrolysis Powers Transport of Lipopolysaccharide Across the Periplasm in E. coli

[Authors]: Suguru Okuda, Elizaveta Freinkman, and Daniel Kahne

[Abstract]: Millions of molecules of lipopolysaccharide (LPS) must be assembled on the Escherichia coli cell surface each time the cell divides. The biogenesis of LPS requires seven essential lipopolysaccharide transport (Lpt) proteins to move LPS from the inner membrane through the periplasm to the cell surface. However, no intermediate transport states have been observed. We developed methods to observe intermediate LPS molecules bound to Lpt proteins in the process of being transported in vivo. Movement of individual LPS molecules along these binding sites required multiple rounds of adenosine triphosphate (ATP) hydrolysis in vitro, which suggests that ATP is used to push a continuous stream of LPS through a transenvelope bridge in discrete steps against a concentration gradient.

原文地址

http://www.sciencemag.org/content/338/6111/1214.short

 

本站声明: 生物文库所有文章欢迎转载,所有文章未说明,均属于原创,转载均请注明出处。
本文链接: http://www.bioku.cn/201301/science-lps-lpt-protein-anti-concentration-gradient-transport-atp/
版权所有: 生物文库 - 生物医学、生物技术核心期刊文摘

留言


+ 8 = 十五


沪ICP备12028140号
点击这里给我发消息   点击这里给我发消息