IpaB-IpgC interaction defines binding motif for type III secretion translocator
IpaB-IpgC interaction defines binding motif for type III secretion translocator
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DOI：
10.1073/pnas.0812900106
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发表时间：
2009-06-16
影响因子：
11.1
通讯作者：
Kolbe, Michael
中科院分区：
文献类型：
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作者：
Lunelli, Michele;Lokareddy, Ravi Kumar;Kolbe, Michael
通过III型分泌系统将毒力因子递送到宿主细胞中对于肠细菌的发病机制是必不可少的。分子伴侣在分泌前特异性结合细菌胞质溶胶中的毒力因子。侵袭质粒基因C（IpgC）是一种分子伴侣，它与志贺菌的两种主要毒力因子侵袭质粒抗原（Ipa）B和C结合。在这里，我们报告的晶体结构IpgC单独和复杂的伴侣结合结构域（CBD）的IpaB。分子伴侣以扩展的构象捕获CBD，该构象通过内衬裂缝的保守残基来稳定。共晶结构的分析揭示了一个序列基序，该基序在来自不同细菌的IpaB转运子类中具有功能，如通过等温滴定量热法所确定的。我们的研究结果显示了如何易位伴侣，并可能允许设计的肠道细菌性疾病的抑制剂。
The delivery of virulence factors into host cells through type III secretion systems is essential for enterobacterial pathogenesis. Molecular chaperones bind specifically to virulence factors in the bacterial cytosol before secretion. Invasion plasmid gene C (IpgC) is a chaperone that binds 2 essential virulence factors of Shigella: invasion plasmid antigens (Ipa) B and C. Here, we report the crystal structure of IpgC alone and in complex with the chaperone binding domain (CBD) of IpaB. The chaperone captures the CBD in an extended conformation that is stabilized by conserved residues lining the cleft. Analysis of the cocrystal structure reveals a sequence motif that is functional in the IpaB translocator class from different bacteria as determined by isothermal titration calorimetry. Our results show how translocators are chaperoned and may allow the design of inhibitors of enterobacterial diseases.