Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie de la Méditerranée (IMM), Aix-Marseille Université - CNRS, Marseille, France.
Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique, Marseille, France.
Bioessays. 2017 Oct;39(10). doi: 10.1002/bies.201600262. Epub 2017 Aug 17.
The Type VI secretion system (T6SS) is a multiprotein and mosaic apparatus that delivers protein effectors into prokaryotic or eukaryotic cells. Recent data on the enteroaggregative Escherichia coli (EAEC) T6SS have provided evidence that the TssA protein is a key component during T6SS biogenesis. The T6SS comprises a trans-envelope complex that docks the baseplate, a cytoplasmic complex that represents the assembly platform for the tail. The T6SS tail is structurally, evolutionarily and functionally similar to the contractile tails of bacteriophages. We have shown that TssA docks to the membrane complex, recruits the baseplate complex and initiates and coordinates the polymerization of the inner tube with that of the sheath. Here, we review these recent findings, discuss the variations within TssA-like proteins, speculate on the role of EAEC TssA in T6SS biogenesis and propose future research perspectives.
VI 型分泌系统（T6SS）是一种多蛋白和镶嵌装置，可将蛋白效应器输送到原核或真核细胞中。最近关于肠聚集性大肠杆菌（EAEC）T6SS 的数据提供了证据，表明 TssA 蛋白是 T6SS 生物发生过程中的关键组成部分。T6SS 包括一个跨包膜复合物，该复合物对接底座板，一个细胞质复合物，代表尾部的组装平台。T6SS 尾部在结构、进化和功能上与噬菌体的收缩尾相似。我们已经表明，TssA 与膜复合物结合，募集底座板复合物，并启动和协调内管与鞘的聚合。在这里，我们回顾这些最近的发现，讨论 TssA 样蛋白的变化，推测 EAEC TssA 在 T6SS 生物发生中的作用，并提出未来的研究展望。
