1P5V: X-ray structure of the Caf1M:Caf1 chaperone:subunit preassembly complex

Most gram-negative pathogens express fibrous adhesive virulence organelles that mediate targeting to the sites of infection. The F1 capsular antigen from the plague pathogen Yersinia pestis consists of linear fibers of a single subunit (Caf1) and serves as a prototype for nonpilus organelles assembled via the chaperone/usher pathway. Genetic data together with high-resolution X-ray structures corresponding to snapshots of the assembly process reveal the structural basis of fiber formation. Comparison of chaperone bound Caf1 subunit with the subunit in the fiber reveals a novel type of conformational change involving the entire hydrophobic core of the protein. The observed conformational change suggests that the chaperone traps a high-energy folding intermediate of Caf1. A model is proposed in which release of the subunit allows folding to be completed, driving fiber formation.
PDB ID: 1P5VDownload
MMDB ID: 23599
PDB Deposition Date: 2003/4/28
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1P5V: dimeric; determined by author and by software (PISA)
Molecular Components in 1P5V
Label Count Molecule
Proteins (2 molecules)
Chaperone Protein Caf1m(Gene symbol: caf1M)
Molecule annotation
F1 Capsule Antigen(Gene symbol: caf1)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB