Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
J Bacteriol. 2023 Mar 21;205(3):e0043822. doi: 10.1128/jb.00438-22. Epub 2023 Feb 27.
Bacterial conjugation, a form of horizontal gene transfer, relies on a type 4 secretion system (T4SS) and a set of nonstructural genes that are closely linked. These nonstructural genes aid in the mobile lifestyle of conjugative elements but are not part of the T4SS apparatus for conjugative transfer, such as the membrane pore and relaxosome, or the plasmid maintenance and replication machineries. While these nonstructural genes are not essential for conjugation, they assist in core conjugative functions and mitigate the cellular burden on the host. This review compiles and categorizes known functions of nonstructural genes by the stage of conjugation they modulate: dormancy, transfer, and new host establishment. Themes include establishing a commensalistic relationship with the host, manipulating the host for efficient T4SS assembly and function and assisting in conjugative evasion of recipient cell immune functions. These genes, taken in a broad ecological context, play important roles in ensuring proper propagation of the conjugation system in a natural environment.
细菌接合是一种水平基因转移形式，依赖于一种类型 4 分泌系统 (T4SS) 和一组紧密连锁的非结构基因。这些非结构基因有助于可移动的接合元件的生活方式，但不是 T4SS 设备用于接合转移的一部分，例如膜孔和松弛体，或质粒维持和复制机制。虽然这些非结构基因对接合不是必需的，但它们有助于核心接合功能，并减轻宿主的细胞负担。本综述通过它们调节的接合阶段，将非结构基因的已知功能进行分类和归类：休眠、转移和新宿主建立。主题包括与宿主建立共生关系、操纵宿主以实现高效 T4SS 组装和功能以及协助接合逃避受体细胞免疫功能。从广泛的生态背景来看，这些基因在确保接合系统在自然环境中的正常传播中发挥着重要作用。
