部分革兰氏阴性菌脂多糖运输蛋白LptD的结构及功能研究进展

Structure and function of LptD in some Gram-negative bacteria

在革兰氏阴性菌中,脂多糖是外膜的重要组成部分,并参与构成细菌的固有免疫。而在大多数革兰氏阴性菌中,Lpt系统都是运输脂多糖的唯一途径,在该系统中LptD作为一个跨膜的外膜蛋白,也是脂多糖输出的最后一步,因此被许多学者称作脂多糖运输的"命门"。LptD参与多种重要的生物学功能,包括有机溶剂耐受性、疏水性抗生素耐受性、膜通透性等。但近来的研究表明,LptD最重要的功能是参与了脂多糖的运输,也因为其参与脂多糖运输而具有了多种功能。本文重点介绍部分革兰氏阴性菌LptD的蛋白结构及其功能研究进程,以期为进一步研究其它革兰氏阴性菌脂多糖运输通路(Lpt通路)及该通路上各蛋白间的相互作用机制提供参考。

Lipopolysaccharide plays an important role in the outer membrane of most Gram-negative bacterium, because it consists of the innate immune system for these bacteria. Lptsystem is the only pathway to transport lipopolysaccharide in most Gram-negative bacteria. Among them, the outer membrane protein LptD is involved in the last step of lipopolysaccharide transportation, so it is regarded as a ＂vital gate＂. LptD is involved in a variety of biological processes, including organic solvent tolerance, hydrophobic antibiotic resistance and membrane permeability. Recent studies have shown that the most important function of LptD is its role in the transportation of lipopolysaccharide. To help further understand LptD and reveal the Lptmechanism in other gram-negative bacteria, we described the structure and functions of LptD in some Gram-negative bacteria.