The N-Terminal GYPSY Motif Is Required for Pilin-Specific Sortase SrtC1 Functionality in Lactobacillus rhamnosus Strain GG

PLoS One. 2016 Apr 12;11(4):e0153373. doi: 10.1371/journal.pone.0153373. eCollection 2016.

Abstract

Predominantly identified in pathogenic Gram-positive bacteria, sortase-dependent pili are also found in commensal species, such as the probiotic-marketed strain Lactobacillus rhamnosus strain GG. Pili are typically associated with host colonization, immune signalling and biofilm formation. Comparative analysis of the N-terminal domains of pilin-specific sortases from various piliated Gram-positive bacteria identified a conserved motif, called GYPSY, within the signal sequence. We investigated the function and role of the GYPSY residues by directed mutagenesis in homologous (rod-shaped) and heterologous (coccoid-shaped) expression systems for pilus formation. Substitutions of some of the GYPSY residues, and more specifically the proline residue, were found to have a direct impact on the degree of piliation of Lb. rhamnosus GG. The present findings uncover a new signalling element involved in the functionality of pilin-specific sortases controlling the pilus biogenesis of Lb. rhamnosus GG and related piliated Gram-positive species.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / metabolism*
  • Fimbriae Proteins / metabolism*
  • Lacticaseibacillus rhamnosus / metabolism*
  • Protein Sorting Signals
  • Protein Structure, Tertiary
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Protein Sorting Signals
  • Fimbriae Proteins