The Non-Lantibiotic Bacteriocin Garvicin Q Targets Man-PTS in a Broad Spectrum of Sensitive Bacterial Genera

Sci Rep. 2017 Aug 21;7(1):8359. doi: 10.1038/s41598-017-09102-7.

Abstract

Mannose phosphotransferase system (Man-PTS) is the main mannose permease in bacteria but it is also a known receptor for subclass IIa bacteriocins (pediocin-like group) as well as subclass IId lactococcin A (LcnA) and lactococcin B (LcnB) (LcnA-like group). Subclass IIa bacteriocins exhibit a strong activity against Listeria spp. but they are not against Lactococcus spp. In contrast, the LcnA-like bacteriocins act only against Lactococcus lactis strains. Garvicin Q (GarQ) is a subclass IId bacteriocin with minor similarity to LcnA-like bacteriocins and a relatively broad antimicrobial spectrum including, among others, Listeria and Lactococcus spp. To identify the GarQ receptor, we obtained GarQ-resistant mutants of Lactococcus garvieae IBB3403 and L. lactis IL1403 and sequenced their genomes that revealed mutations in genes encoding the membrane-bound Man-PTS IIC or IID subunits encoded by ptnCD in L. lactis and manCD in L. garvieae. This is the first time that a bacteriocin outside the pediocin- and LcnA-like groups is shown to target Man-PTS. The interaction between GarQ and Man-PTS may occur through a new binding pattern involving specific amino acids highly conserved among the GarQ-sensitive bacterial species located in the N-terminal part and extracellular loops of subunit IID and in transmembrane region of IIC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / antagonists & inhibitors*
  • Bacteriocins / pharmacology*
  • Lactococcus / classification
  • Lactococcus / drug effects
  • Lactococcus / enzymology*
  • Mannose / metabolism*
  • Phosphoenolpyruvate Sugar Phosphotransferase System / antagonists & inhibitors*
  • Sequence Homology

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Bacteriocins
  • Phosphoenolpyruvate Sugar Phosphotransferase System
  • phosphoenolpyruvate-mannose phosphotransferase
  • Mannose