T9SS蛋白质分泌系统及其在微生物降解多糖过程中的功能  

Function of T9SS in the process of polysaccharides biodegradation

作　　者：陈晓艺[1] 方程 王辛 赵鑫 CHEN Xiaoyi;FANG Cheng;WANG Xin;ZHAO Xin(School of Biological Engineering,Dalian Polytechnic University,Dalian 116034,China)

机构地区：[1]大连工业大学生物工程学院,辽宁大连116034

出　　处：《大连工业大学学报》2021年第1期6-12,共7页Journal of Dalian Polytechnic University

基　　金：国家自然科学基金项目(31801469);辽宁省教育厅A类项目(2017J029).

摘　　要：对T9SS的组成与结构、蛋白分泌机制及典型分泌蛋白的功能等研究进展进行了总结。T9SS是新近发现的一类蛋白分泌系统,主要存在于拟杆菌门的部分微生物中,是微生物细胞释放毒力因子、摄取营养物质或者分泌滑动蛋白进行细胞运动的重要跨膜运输通道。T9SS是由至少19种组分构成的蛋白复合体,整体结构跨越细胞内膜和外膜。通过T9SS转运的蛋白质普遍具有保守的C末端结构域(CTD),分泌蛋白在N端信号肽的引导下通过细胞内膜上的Sec通道被转运至周质空间后,在CTD信号的作用下进一步经外膜上的孔道被运送至胞外。大部分被运送到胞外的蛋白质通过与外膜上的脂多糖A-LPS共价结合而被锚定在细胞表面,只有少部分以游离状态释放到培养基质中。通过T9SS系统转运的蛋白质主要包括黏附素、血细胞凝集素、蛋白酶、脂酶和糖苷水解酶等。The machinery components of T9SS and the function of its substrates was presented.Type IX secretion system(T9SS)is recently discovered and only found in some species of the Bacteroidetes phylum.T9SS plays important roles in the process of virulence secretion,nutrients acquisition or gliding motility,depending on the lifestyle of the bacteria.Proteins secreted by T9SS have an N-terminal signal peptide for translocation across the inner membrane via the Sec translocon and a C-terminal domain(CTD)for secretion across the outer membrane(OM)via T9SS.Upon translocation across OM,CTD is removed by a protease and an anionic LPS(A-LPS)is attached to the newly formed C-terminus.As a result,the secreted protein could be covalently attached to the bacterial surface or secreted into the extracellular milieu.Proteins secreted by T9SS mainly included adhesions,hemagglutinins,proteases,lipases and carbohydrate hydrolases.

关 键 词：T9SS 蛋白分泌 多糖降解 细菌滑动性 

分 类 号：Q93[生物学—微生物学]