Characterization of a Type III secretion substrate specificity switch (T3S4) domain in YscP from Yersinia enterocolitica
Characterization of a Type III secretion substrate specificity switch (T3S4) domain in YscP from Yersinia enterocolitica
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DOI：
10.1111/j.1365-2958.2005.04534.x
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发表时间：
2005-04-01
影响因子：
3.6
通讯作者：
Cornelis, GR
中科院分区：
文献类型：
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作者：
Agrain, C;Callebaut, I;Cornelis, GR
耶尔森氏菌YSC注射体末端的针头长度由YscP决定，YscP是一种充当分子尺子的蛋白质。此外，YSCP是YOP分泌所必需的。在本论文中，通过系统的缺失分析，我们准确地定位了YOP分泌所需的区域在残基405和500之间。由于YscP的这个C-末端区域也被证明控制针头的长度，它可能代表着机器的底物特异性开关。通过生物信息学分析，我们发现该区域具有球状结构，具有原始的α/β折叠，具有P-x-L-G特征，推测没有催化活性。尽管序列相似性非常有限，但这种结构在许多不同注射体中被认为控制针头长度的蛋白质中是保守的，在控制鞭毛钩长的Flik家族成员中也是如此。因此，这个区域代表了一个新的蛋白质结构域，我们称之为T3S4，用于III型分泌底物特异性开关。YscP的T3S4结构域可以被ASCP(Salmonicida气单胞菌)或PSCP(铜绿假单胞菌)的T3S4结构域取代，但不能被Flik的T3S4结构域取代，这表明尽管有一个共同的全球结构，但这些结构域需要与它们的伴侣蛋白在分泌器官中匹配。
The length of the needle ending the Yersinia Ysc injectisome is determined by YscP, a protein acting as a molecular ruler. In addition, YscP is required for Yop secretion. In the present paper, by a systematic deletion analysis, we localized accurately the region required for Yop secretion between residues 405 and 500. As this C-terminal region of YscP has also been shown to control needle length it probably represents the substrate specificity switch of the machinery. By a bioinformatics analysis, we show that this region has a globular structure, an original alpha/beta fold, a P-x-L-G signature and presumably no catalytic activity. In spite of very limited sequence similarities, this structure is conserved among the proteins that are presumed to control the needle length in many different injectisomes and also among members of the FliK family, which control the flagellar hook length. This region thus represents a new protein domain that we called T3S4 for Type III secretion substrate specificity switch. The T3S4 domain of YscP can be replaced by the T3S4 domain of AscP (Aeromonas salmonicida) or PscP (Pseudomonas aeruginosa) but not by the one from FliK, indicating that in spite of a common global structure, these domains need to fit their partner proteins in the secretion apparatus.