A common structural motif in the binding of virulence factors to bacterial secretion chaperones
A common structural motif in the binding of virulence factors to bacterial secretion chaperones
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DOI：
10.1016/j.molcel.2006.01.026
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发表时间：
2006-03-03
期刊：
影响因子：
16
通讯作者：
Stebbins, CE
中科院分区：
文献类型：
--
作者：
Lilic, M;Vujanac, M;Stebbins, CE
沙门氏菌入侵蛋白 A (SipA) 通过 III 型分泌系统 (T3SS) 易位到宿主细胞中，并包含两个区域：一个结构域结合细菌中的同源 III 型分泌伴侣 lnvB 以促进易位，而第二个结构域在宿主细胞中发挥作用，通过聚合肌动蛋白促进细菌摄取。我们在此展示了 SipA 分子伴侣结合域 (CBD) 单独以及与 lnvB 复合的晶体结构。发现 SipA CBD 由非球状多肽和大球状结构域组成，这两者都是与 InvB 结合所必需的。我们还确定了一个结构基序，可以将毒力因子引导至多种病原细菌中的同源伴侣。这种结构基序的破坏会导致来自不同物种的几种分子伴侣-底物复合物的不稳定，以及沙门氏菌分泌的损害。
Salmonella invasion protein A (SipA) is translocated into host cells by a type III secretion system (T3SS) and comprises two regions: one domain binds its cognate type III secretion chaperone, lnvB, in the bacterium to facilitate translocation, while a second domain functions in the host cell, contributing to bacterial uptake by polymerizing actin. We present here the crystal structures of the SipA chaperone binding domain (CBD) alone and in complex with lnvB. The SipA CBD is found to consist of a nonglobular polypeptide as well as a large globular domain, both of which are necessary for binding to InvB. We also identify a structural motif that may direct virulence factors to their cognate chaperones in a diverse range of pathogenic bacteria. Disruption of this structural motif leads to a destabilization of several chaperone-substrate complexes from different species, as well as an impairment of secretion in Salmonella.