Biochemistry and Electrochemistry Research Unit and School of Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Biochemistry and Electrochemistry Research Unit and School of Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Payupnai, Wangchan, Rayong 21210, Thailand.
Int J Biol Macromol. 2019 May 1;128:985-993. doi: 10.1016/j.ijbiomac.2019.02.064. Epub 2019 Feb 13.
Periplasmic solute-binding proteins (SBPs) serve as molecular shuttles that assist the transport of small solutes from the outer membrane to the inner membrane of all Gram-negative bacteria. Based on the available crystal structures, SBPs are classified into seven clusters, A-G, and are further divided into subclusters, IV. This minireview is focused on the classification, structure and substrate specificity of a distinct class of SBPs specific for chitooligosaccharides (CBPs). To date, only two structures of CBP homologues, VhCBP and VcCBP, have been reported in the marine Vibrio species, with exposition of their limited function. The Vibrio CBPs are structurally classified as cluster C/subcluster IV SBPs that exclusively recognize β-1,4- or β-1,3-linked linear oligosaccharides. The overall structural feature of the Vibrios CBPs is most similar to the cellobiose-binding orthologue from the hyperthermophilic bacterium Thermotoga maritima. This similarity provides an opportunity to engineer the substrate specificity of the proteins and to control the uptake of chitinous and cellulosic nutrients in marine bacteria.
周质溶质结合蛋白（SBPs）作为分子穿梭物，协助将小溶质从革兰氏阴性菌的外膜转运到内膜。根据现有的晶体结构，SBPs 分为七个簇，A-G，并进一步分为亚簇 IV。这篇综述主要介绍了一类独特的周质溶质结合蛋白（CBPs）的分类、结构和底物特异性，该类蛋白专门识别壳寡糖。迄今为止，只有两种海洋弧菌属 Vibrio 物种的 CBP 同源物 VhCBP 和 VcCBP 的结构被报道，其功能有限。Vibrio 型 CBPs 在结构上被归类为簇 C/亚簇 IV SBPs，它们专门识别β-1,4-或β-1,3-连接的线性寡糖。Vibrio 型 CBPs 的整体结构特征与来自嗜热菌 Thermotoga maritima 的纤维二糖结合同源物最为相似。这种相似性为工程化蛋白质的底物特异性和控制海洋细菌中壳质和纤维素营养物质的摄取提供了机会。
