4B0E

Crystal structure of the Caf1A usher protein N-terminal domain from Yersinia pestis

Summary for 4B0E

• Entry DOI: 10.2210/pdb4b0e/pdb
• Related: 2XET 4AY0 4AYF 4AZ8 4B0M
• Descriptor: F1 CAPSULE-ANCHORING PROTEIN (2 entities in total)
• Functional Keywords: transport protein, chaperone-usher pathway, pili assembly
• Biological source: YERSINIA PESTIS
• Total number of polymer chains: 4
• Total formula weight: 61545.58

Authors

Dubnovitsky, A.,Yu, X.D.,Pudney, A.F.,MacIntyre, S.,Knight, S.D.,Zavialov, A.V. (deposition date: 2012-07-02, release date: 2012-09-26, Last modification date: 2024-10-09)

Primary citation

Di Yu, X.,Dubnovitsky, A.,Pudney, A.F.,Macintyre, S.,Knight, S.D.,Zavialov, A.V.
Allosteric Mechanism Controls Traffic in the Chaperone/Usher Pathway.
Structure, 20:1861-, 2012

PubMed Abstract: Many virulence organelles of Gram-negative bacterial pathogens are assembled via the chaperone/usher pathway. The chaperone transports organelle subunits across the periplasm to the outer membrane usher, where they are released and incorporated into growing fibers. Here, we elucidate the mechanism of the usher-targeting step in assembly of the Yersinia pestis F1 capsule at the atomic level. The usher interacts almost exclusively with the chaperone in the chaperone:subunit complex. In free chaperone, a pair of conserved proline residues at the beginning of the subunit-binding loop form a "proline lock" that occludes the usher-binding surface and blocks usher binding. Binding of the subunit to the chaperone rotates the proline lock away from the usher-binding surface, allowing the chaperone-subunit complex to bind to the usher. We show that the proline lock exists in other chaperone/usher systems and represents a general allosteric mechanism for selective targeting of chaperone:subunit complexes to the usher and for release and recycling of the free chaperone.

PubMed: 22981947
DOI: 10.1016/J.STR.2012.08.016

Experimental method

X-RAY DIFFRACTION (2 Å)