PDBsum entry 4b0e

Transport protein

PDB id: 4b0e

Contents

Protein chains

96 a.a.

91 a.a.

100 a.a.

Waters ×235

PDB id:

4b0e

Name:

Transport protein

Title:

Crystal structure of the caf1a usher protein n-terminal domain from yersinia pestis

Structure:

F1 capsule-anchoring protein. Chain: a, b, c, d. Fragment: n-terminal domain, residues 23-158. Synonym: caf1a usher protein. Engineered: yes

Source:

Yersinia pestis. Organism_taxid: 632. Expressed in: escherichia coli. Expression_system_taxid: 469008. Expression_system_variant: star.

Resolution:

2.00Å R-factor: 0.205 R-free: 0.261

Authors:

A.Dubnovitsky,X.D.Yu,A.F.Pudney,S.Macintyre,S.D.Knight,A.V.Zavialov

Key ref:

X.Di Yu et al. (2012). Allosteric mechanism controls traffic in the chaperone/usher pathway. Structure, 20, 1861-1871. PubMed id: 22981947

Date:

02-Jul-12 Release date: 26-Sep-12

Protein chains

P26949  (CAF1A_YERPE) -  F1 capsule-anchoring protein from Yersinia pestis

Seq: 833 a.a.

Struc: 96 a.a.

Protein chain

P26949  (CAF1A_YERPE) -  F1 capsule-anchoring protein from Yersinia pestis

Seq: 833 a.a.

Struc: 91 a.a.

Protein chain

P26949  (CAF1A_YERPE) -  F1 capsule-anchoring protein from Yersinia pestis

Seq: 833 a.a.

Struc: 100 a.a.

Structure 20:1861-1871 (2012)

PubMed id: 22981947

Allosteric mechanism controls traffic in the chaperone/usher pathway.

X.Di Yu, A.Dubnovitsky, A.F.Pudney, S.Macintyre, S.D.Knight, A.V.Zavialov.

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.