2FM8: Crystal Structure Of The Salmonella Secretion Chaperone Invb In Complex With Sipa

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.
PDB ID: 2FM8Download
MMDB ID: 38289
PDB Deposition Date: 2006/1/8
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 2FM8: trimeric; determined by author and by software (PISA)
Molecular Components in 2FM8
Label Count Molecule
Proteins (3 molecules)
Surface Presentation of Antigens Protein Spak(Gene symbol: invB)
Molecule annotation
Cell Invasion Protein Sipa
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB