2FM8

Crystal Structure of the Salmonella Secretion Chaperone InvB in Complex with SipA

Summary for 2FM8

• Entry DOI: 10.2210/pdb2fm8/pdb
• Descriptor: Surface presentation of antigens protein spaK, Cell invasion protein sipA (3 entities in total)
• Functional Keywords: type iii secretion, chaperone, translocation, protein folding, virulence, salmonella, bacterial, chaperone-cell invasion complex, chaperone/cell invasion
• Biological source: Salmonella typhimurium; More
• Total number of polymer chains: 3
• Total formula weight: 55931.15

Authors

Lilic, M.,Vujanac, M.,Stebbins, C.E. (deposition date: 2006-01-08, release date: 2006-03-21, Last modification date: 2024-02-14)

Primary citation

Lilic, M.,Vujanac, M.,Stebbins, C.E.
A common structural motif in the binding of virulence factors to bacterial secretion chaperones.
Mol.Cell, 21:653-664, 2006

PubMed Abstract: 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, InvB, 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 InvB. 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.

PubMed: 16507363
DOI: 10.1016/j.molcel.2006.01.026

Experimental method

X-RAY DIFFRACTION (2.2 Å)