Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan.
Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan.
Curr Opin Microbiol. 2016 Feb;29:22-9. doi: 10.1016/j.mib.2015.10.001. Epub 2015 Oct 31.
Type IV secretion systems (T4SSs) are transporters that span the bacterial inner and outer membranes and deliver substrate biomolecules, including proteins and DNAs, into cells. Recent progress in structural analyses of conjugative plasmid-encoded type IVA secretion systems (T4ASSs) has revealed a unique molecular architecture. The essential virulence system, the Dot/Icm Type IVB secretion system (T4BSS) encoded by the intracellular bacterial pathogen Legionella pneumophila is distantly related to T4ASSs. Molecular and structural analyses of the Dot/Icm T4BSS have provided insights into the mechanisms of assembly and function. Here we highlight the chimeric quality of T4BSSs that possess components with similarity to many bacterial secretion systems.
IV 型分泌系统（T4SSs）是一种跨细菌内膜和外膜的转运器，可将底物生物分子（包括蛋白质和 DNA）输送到细胞内。最近对可移动质粒编码的 IVA 型 T4SSs 的结构分析取得了进展，揭示了一种独特的分子结构。胞内细菌病原体嗜肺军团菌的 Dot/Icm 型 IVB 分泌系统（T4BSS）是一种必需的毒力系统，与 T4ASSs 关系较远。Dot/Icm T4BSS 的分子和结构分析为组装和功能机制提供了线索。在这里，我们强调了 T4BSS 具有与许多细菌分泌系统相似组件的嵌合特性。
