3SOK: Dichelobacter Nodosus Pilin Fima

Pilin proteins assemble into Type IV pili (T4P), surface-displayed bacterial filaments with virulence functions including motility, attachment, transformation, immune escape, and colony formation. However, challenges in crystallizing full-length fiber-forming and membrane protein pilins leave unanswered questions regarding pilin structures, assembly, functions, and vaccine potential. Here we report pilin structures of full-length DnFimA from the sheep pathogen Dichelobacter nodosus and FtPilE from the human pathogen Francisella tularensis at 2.3 and 1 A resolution, respectively. The DnFimA structure reveals an extended kinked N-terminal alpha-helix, an unusual centrally located disulfide, conserved subdomains, and assembled epitopes informing serogroup vaccines. An interaction between the conserved Glu-5 carboxyl oxygen and the N-terminal amine of an adjacent subunit in the crystallographic dimer is consistent with the hypothesis of a salt bridge between these groups driving T4P assembly. The FtPilE structure identifies an authentic Type IV pilin and provides a framework for understanding the role of T4P in F. tularensis virulence. Combined results define a unified pilin architecture, specialized subdomain roles in pilus assembly and function, and potential therapeutic targets.
PDB ID: 3SOKDownload
MMDB ID: 94797
PDB Deposition Date: 2011/6/30
Updated in MMDB: 2011/11
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 3SOK: monomeric; determined by author and by software (PISA)
Molecular Components in 3SOK
Label Count Molecule
Protein (1 molecule)
Fimbrial Protein
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB