The rpoN (sigma54) gene from Listeria monocytogenes is involved in resistance to mesentericin Y105, an antibacterial peptide from Leuconostoc mesenteroides.
To gain insight into the mode of action of mesentericin Y105, a bacteriocin bactericidal agent against Listeria monocytogenes, we undertook to identify the listerial factors mediating this susceptibility by using a genetic approach. Transposon mutants resistant to the bacteriocin were obtained. One of them corresponded to a transposon insertion in a gene (rpoN) encoding a putative protein (447 amino acids) with strong homologies to alternative transcriptional sigma54 factors, including that of Bacillus subtilis (38% identity). Complementation experiments with the wild-type rpoN gene demonstrated that the insertion in rpoN was responsible for the resistance phenotype in L. monocytogenes. Moreover, expression of the L. monocytogenes rpoN gene in an rpoN mutant strain of B. subtilis promoted transcription of a sigma54-dependent operon in the presence of the associated regulator. These results demonstrate that the L. monocytogenes rpoN gene encodes a new sigma54 factor.
Robichon
D
D
Laboratoire de Biologie Moléculaire, URA CNRS 1172, IBMIG, UFR Sciences, Poitiers, France.
Gouin
E
E
Débarbouillé
M
M
Cossart
P
P
Cenatiempo
Y
Y
Héchard
Y
Y
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001430:Bacteriocins / Q000494:pharmacology*; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000145:classification / Q000235:genetics*; D004352:Drug Resistance, Microbial; D005816:Genetic Complementation Test; D007934:Leuconostoc; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010455:Peptides; D051877:RNA Polymerase Sigma 54; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000145:classification / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001430:Bacteriocins; D004268:DNA-Binding Proteins; D010455:Peptides; D012808:Sigma Factor; C079275:mesentericin Y105 protein, Leuconostoc mesenteroides; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54