中文摘要：

细菌的分泌系统与细菌的生存及致病性密切相关。细菌的分泌系统包括I-VI型,其中,IV型分泌系统是与细菌接合机制有关的一类分泌系统。IV型分泌系统不但可以转运DNA,还可以转运蛋白质及核糖核蛋白复合物等大分子物质,这点区别于其他几种分泌系统。IV型分泌系统介导基因水平转移,通过细菌间接合作用,传递抗性基因和毒力基因,有利于细菌进化;另一方面,IV型分泌系统转运效应蛋白质分子到宿主细胞,参与细菌致病。本文着重从IV型分泌系统几种主要类型的分泌机制等方面对IV型分泌系统进行概述。

英文摘要：

Protein secretion is required for numerous aspects of the acquisition. Now these secretion systems in bacteria are divided into six types from I to VI. Type IV secretion systems （T4SS） are the secretion systems related to the conjugation machinery. The T4SSs are unique among other bacterial secretion systems for their ability to transfer both proteins and nucleoprotein complexes. T4SSs mediate horizontal gene transfer, especially through the dissemination of antibiotic resistance and virulence genes that facilitate to the evolution of pathogens. They can also deliver bacterial effector proteins to host cells, thus contributing to virulence. Here we summarize the research progress of the classification and the mechanism of the T4SSs.