3gz1
From Proteopedia
Crystal structure of IpgC in complex with the chaperone binding region of IpaB
Structural highlights
Function[IPGC_SHIFL] Assists the correct folding of nascent IpaB. Once it is bound to IpaB, it binds to IpaC and impedes their premature association that would lead to their degradation in the absence of IpcG. [IPAB_SHIFL] Effector proteins function to alter host cell physiology and promote bacterial survival in host tissues. Forms a pore with IpaC, which is inserted into the host cell membrane through the Mxi/Spa apparatus, during cell contact. This pore probably allows the translocation of IpaA. IpaB has also been found to be necessary and sufficient to activate macrophage apoptosis by binding to interleukin-1 beta converting enzyme (ICE). Has also been shown to be important, along with IpaD, to block or regulate secretion through the Mxi/Spa translocon in the presence or absence of the secretion signal, respectively. Through interaction with host human MAD2L2, constitutively activates the anaphase-promoting complex APC and induces a cell cycle arrest to prevent epithelial renewal in order to promote bacterial colonization.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. IpaB-IpgC interaction defines binding motif for type III secretion translocator.,Lunelli M, Lokareddy RK, Zychlinsky A, Kolbe M Proc Natl Acad Sci U S A. 2009 May 28. PMID:19478065[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||||
