Type VI secretion apparatus and phage tail-associated protein complexes share a common evolutionary origin
Type VI secretion apparatus and phage tail-associated protein complexes share a common evolutionary origin
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DOI：
10.1073/pnas.0813360106
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发表时间：
2009-03-17
影响因子：
11.1
通讯作者：
Mekalanos, John J.
中科院分区：
文献类型：
--
作者：
Leiman, Petr G.;Basler, Marek;Mekalanos, John J.
蛋白质分泌是病原微生物的共同特征。革兰氏阴性细菌病原体使用至少6个不同的胞外蛋白分泌系统，通过其多层细胞膜输出蛋白质，在某些情况下还进入宿主细胞。其中最普遍的是新发现的VI型分泌系统(T6SS)，它由15-20种蛋白质组成，其生化功能尚不清楚。通过结晶学、生物化学和生物信息学分析，我们鉴定了3个与噬菌体尾部蛋白同源的T6SS组分。这些蛋白质包括尾管蛋白；位于尾管末端的穿膜针；以及与针和管相关的另一种蛋白质。我们认为T6SS是一个多组分的结构，其胞外部分在结构和功能上都类似于噬菌体尾巴，这是一种有效的机器，可以将蛋白质和DNA通过脂膜转移到细胞内。
Protein secretion is a common property of pathogenic microbes. Gram-negative bacterial pathogens use at least 6 distinct extracellular protein secretion systems to export proteins through their multilayered cell envelope and in some cases into host cells. Among the most widespread is the newly recognized Type VI secretion system (T6SS) which is composed of 15-20 proteins whose biochemical functions are not well understood. Using crystallographic, biochemical, and bioinformatic analyses, we identified 3 T6SS components, which are homologous to bacteriophage tail proteins. These include the tail tube protein; the membrane-penetrating needle, situated at the distal end of the tube; and another protein associated with the needle and tube. We propose that T6SS is a multicomponent structure whose extracellular part resembles both structurally and functionally a bacteriophage tail, an efficient machine that translocates proteins and DNA across lipid membranes into cells.