Structure and Biogenesis of the Capsular F1 Antigen From Yersinia Pestis: Preserved Folding Energy Drives Fiber Formation

Cell. 2003 May 30;113(5):587-96. doi: 10.1016/s0092-8674(03)00351-9.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial / biosynthesis*
  • Antigens, Bacterial / genetics
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Cysteine / genetics
  • Cysteine / metabolism
  • Fimbriae, Bacterial / genetics
  • Fimbriae, Bacterial / metabolism
  • Models, Molecular
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed / genetics
  • Organelles / metabolism*
  • Protein Folding*
  • Protein Structure, Quaternary / genetics
  • Sequence Homology, Amino Acid
  • Yersinia pestis / genetics
  • Yersinia pestis / metabolism*


  • Antigens, Bacterial
  • Bacterial Proteins
  • Molecular Chaperones
  • caf1 protein, Yersinia pestis
  • Cysteine

Associated data

  • PDB/1P5U
  • PDB/1P5V