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Sensitivity to the two‐peptide bacteriocin lactococcin G is dependent on UppP , an enzyme involved in cell‐wall synthesis
Author(s) -
Kjos Morten,
Oppegård Camilla,
Diep Dzung B.,
Nes Ingolf F.,
Veening JanWillem,
NissenMeyer Jon,
Kristensen Tom
Publication year - 2014
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12632
Subject(s) - bacteriocin , biology , lactococcus lactis , mutant , g protein coupled receptor , peptidoglycan , lantibiotics , receptor , gene , lactococcus , biochemistry , dictyostelium , genetics , bacteria , lactic acid
Summary Most bacterially produced antimicrobial peptides (bacteriocins) are thought to kill target cells by a receptor‐mediated mechanism. However, for most bacteriocins the receptor is unknown. For instance, no target receptor has been identified for the two‐peptide bacteriocins (class IIb ), whose activity requires the combined action of two individual peptides. To identify the receptor for the class IIb bacteriocin lactococcin G , which targets strains of L actococcus lactis , we generated 12 lactococcin G ‐resistant mutants and performed whole‐genome sequencing to identify mutations causing the resistant phenotype. Remarkably, all had a mutation in or near the gene uppP ( bacA ), encoding an undecaprenyl pyrophosphate phosphatase; a membrane protein involved in peptidoglycan synthesis. Nine mutants had stop codons or frameshifts in the uppP gene, two had point mutations in putative regulatory regions and one caused an amino acid substitution in UppP . To verify the receptor function of UppP , it was shown that growth of non‐sensitive S treptococcus pneumoniae could be inhibited by lactococcin G when L . lactis uppP was expressed in this bacterium. Furthermore, we show that the related class IIb bacteriocin enterocin 1071 also uses UppP as receptor. The approach used here should be broadly applicable to identify receptors for other bacteriocins as well.