The zinc metalloprotease of Listeria monocytogenes is required for maturation of phosphatidylcholine phospholipase C: direct evidence obtained by gene complementation.
The maturation of the 33-kDa proenzyme to the 29-kDa phosphatidylcholine phospholipase C (PC-PLC) of Listeria monocytogenes requires the production of the zinc metalloprotease encoded by mpl, the proximal gene of the lecithinase operon. We recently described a low-virulence lecithinase-deficient mutant of L. monocytogenes EGD-SmR, designated JL762, generated by a single insertion of transposon Tn1545 in mpl. This mutant failed to produce the 29-kDa PC-PLC, an exoenzyme probably involved in cell-to-cell spreading. The role of the product of the mpl gene in production of PC-PLC was investigated in trans-complementation experiments. The entire mpl gene was cloned in a plasmid able to replicate in L. monocytogenes. This recombinant plasmid was introduced into JL762 and restored the lecithinase phenotype on egg yolk agar and the production of the active 29-kDa PC-PLC in culture supernatants and partially restored the level of virulence. These results demonstrate that zinc-dependent metalloprotease of L. monocytogenes is involved in the virulence of this bacteria at least through its action on PC-PLC.
Laboratoire de Microbiologie, Faculté de Médecine Necker-Enfants Malades, Paris, France.
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Poyart
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Abachin
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Razafimanantsoa
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Berche
D001426:Bacterial Proteins; D001483:Base Sequence; D015153:Blotting, Western; D004251:DNA Transposable Elements; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008089:Listeria monocytogenes / Q000201:enzymology* / Q000472:pathogenicity; D008666:Metalloendopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D009876:Operon; D010740:Phospholipases / Q000235:genetics; D011499:Protein Processing, Post-Translational; D010738:Type C Phospholipases / Q000378:metabolism*
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D009838:Oligodeoxyribonucleotides; D010740:Phospholipases; D010738:Type C Phospholipases; D008666:Metalloendopeptidases; C080367:mpl protein, Listeria monocytogenes