Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.
Plasmid. 2013 Nov;70(3):289-302. doi: 10.1016/j.plasmid.2013.09.005. Epub 2013 Oct 12.
Bacterial conjugation presents the most important means to spread antibiotic resistance and virulence factors among closely and distantly related bacteria. Conjugative plasmids are the mobile genetic elements mainly responsible for this task. All the genetic information required for the horizontal transmission is encoded on the conjugative plasmids themselves. Two distinct concepts for horizontal plasmid transfer in Gram-positive bacteria exist, the most prominent one transports single stranded plasmid DNA via a multi-protein complex, termed type IV secretion system, across the Gram-positive cell envelope. Type IV secretion systems have been found in virtually all unicellular Gram-positive bacteria, whereas multicellular Streptomycetes seem to have developed a specialized system more closely related to the machinery involved in bacterial cell division and sporulation, which transports double stranded DNA from donor to recipient cells. This review intends to summarize the state of the art of prototype systems belonging to the two distinct concepts; it focuses on protein key players identified so far and gives future directions for research in this emerging field of promiscuous interbacterial transport.
细菌接合是在亲缘关系密切和不密切的细菌之间传播抗生素耐药性和毒力因子最重要的手段。可移动的质粒是主要负责这一任务的可移动遗传元件。水平传播所需的所有遗传信息都编码在可移动的质粒上。革兰氏阳性菌中存在两种不同的水平质粒转移概念，其中最突出的一种是通过一种称为 IV 型分泌系统的多蛋白复合物，穿过革兰氏阳性菌细胞包膜，转移单链质粒 DNA。IV 型分泌系统几乎存在于所有单细胞革兰氏阳性菌中，而多细胞链霉菌似乎已经开发出一种与参与细菌细胞分裂和孢子形成的机制更密切相关的特殊系统，该系统将双链 DNA 从供体转移到受体细胞。这篇综述旨在总结属于这两种不同概念的原型系统的最新进展；它侧重于迄今为止确定的蛋白关键因子，并为这一新兴的细菌间混杂运输领域的研究提供未来的方向。
