Ultrahigh Resolution and Full-length Pilin Structures with Insights for Filament Assembly, Pathogenic Functions, and Vaccine Potential.Hartung, S., Arvai, A.S., Wood, T., Kolappan, S., Shin, D.S., Craig, L., Tainer, J.A.
(2011) J Biol Chem 286: 44254-44265
- PubMed: 22027840
- DOI: 10.1074/jbc.M111.297242
- Primary Citation of Related Structures:
- PubMed Abstract:
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 fibe ...
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 Å resolution, respectively. The DnFimA structure reveals an extended kinked N-terminal α-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.
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.