Redefining the PF06864 Pfam family based on Burkholderia pseudomallei PilO2(Bp) S-SAD crystal structure

PLoS One. 2014 Apr 11;9(4):e94981. doi: 10.1371/journal.pone.0094981. eCollection 2014.

Abstract

Type IV pili are surface-exposed filaments and bacterial virulence factors, represented by the Tfpa and Tfpb types, which assemble via specific machineries. The Tfpb group is further divided into seven variants, linked to heterogeneity in the assembly machineries. Here we focus on PilO2(Bp), a protein component of the Tfpb R64 thin pilus variant assembly machinery from the pathogen Burkholderia pseudomallei. PilO2(Bp) belongs to the PF06864 Pfam family, for which an improved definition is presented based on newly derived Hidden Markov Model (HMM) profiles. The 3D structure of the N-terminal domain of PilO2(Bp) (N-PilO2(Bp)), here reported, is the first structural representative of the PF06864 family. N-PilO2(Bp) presents an actin-like ATPase fold that is shown to be present in BfpC, a different variant assembly protein; the new HMM profiles classify BfpC as a PF06864 member. Our results provide structural insight into the PF06864 family and on the Type IV pili assembly machinery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Burkholderia pseudomallei / genetics*
  • Burkholderia pseudomallei / metabolism*
  • Gene Order
  • Models, Molecular
  • Multigene Family*
  • Operon
  • Protein Conformation
  • Protein Folding
  • Protein Interaction Domains and Motifs
  • Virulence Factors

Substances

  • Bacterial Proteins
  • Virulence Factors

Grants and funding

This work was supported by Fondazione Cariplo (Milano, Italy; www.fondazionecariplo.it) Project: “From Genome to Antigen: a Multidisciplinary Approach towards the Development of an Effective Vaccine against Burkholderia pseudomallei, the Etiological Agent of Melioidosis” (contract number 2009-3577). The funder is a non-profit foundation that had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.