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An extracellular loop of the mannose phosphotransferase system component IIC is responsible for specific targeting by

Morten Kjos1, Zhian Salehian, Ingolf F Nes

  • 1Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, As, Norway.

Journal of Bacteriology
|September 28, 2010
PubMed

Insights

Class IIa bacteriocins recognize specific bacterial targets. Researchers identified a key protein loop in mannose-phosphotransferase systems responsible for this specific recognition by bacteriocins.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacteriocin Research

Background:

  • Class IIa bacteriocins are antimicrobial peptides with a specific target.
  • Mannose-phosphotransferase systems (man-PTS) are involved in bacterial sugar uptake and serve as targets for some bacteriocins.

Purpose of the Study:

  • To identify the specific component of the mannose-phosphotransferase system responsible for class IIa bacteriocin recognition.
  • To understand the molecular basis of bacteriocin-host interaction.

Main Methods:

  • Construction and analysis of chimeric man-PTS genes from Listeria monocytogenes and Lactococcus lactis.
  • Site-directed mutagenesis of man-PTS genes.
  • Bacteriocin activity assays.

Main Results:

  • An extracellular loop of the MptC protein was identified as the critical determinant for class IIa bacteriocin binding.
  • Chimeric and mutated man-PTS proteins showed altered sensitivity to bacteriocins, confirming the role of the identified loop.

Conclusions:

  • The extracellular loop of MptC is the primary recognition site for class IIa bacteriocins.
  • This finding provides a molecular understanding of bacteriocin specificity and opens avenues for engineering bacteriocin activity.

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