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作 者 ：徐丽萍，孙　盼，郭敏亮*

期 刊 ：生命科学 2016年 28卷 3期 页码：377-383

摘 要 ：细菌IV 型分泌系统(type IV secretion system， T4SS) 不仅是农杆菌转运T-DNA 的通道，也是多种质粒接合的通道，还能转运多种底物分子到不同的靶细胞( 包括细菌和真核细胞)，因此，T4SS 的结构及其底物转运机理的研究受到了人们的极大关注，近几年来，这方面的研究进展迅速。农杆菌转运T-DNA 的T4SS 又叫VirB/VirD4 系统，是革兰氏阴性菌中最典型的T4SS 之一，有关细菌IV 型分泌系统的研究均以农杆菌的VirB/VirD4 系统为参考模型。现将综述这几年来在农杆菌T4SS 结构研究方面取得的最新进展，并介绍目前对T4SS 底物转运机理的一些最新认识。

Abstract:Type IV secretion system (T4SS) is not only used for T-DNA transfer by Agrobacterium tumefaciens， but also used for plasmid conjugation by many bacteria. Moreover， many bacteria use T4SS to translocate various substrates into a wide variety of organisms including bacterial and eukaryotic cells. Therefore， the studies on the structure and substrate-translocating mechanism of T4SS continue to attract the concentration of researchers and many important progresses in this research field have been made recently. Agrobacterial T4SS that is used for T-DNA transfer is called VirB/VirD4 system， which is one of the best-characterized T4SSs in Gram-negative bacteria， and thus becomes a typical model of T4SS. This review highlights the recent breakthroughs in the structural biology of Agrobacterial VirB/VirD4 system and summarizes current understanding of the molecular mechanism of T4SS substrate translocation.

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