The Escherichia coli lov gene product connects peptidoglycan synthesis, ribosomes and growth rate.
Mecillinam, a beta-lactam antibiotic which binds specifically to penicillin-binding protein 2 (PBP2), blocks lateral cell-wall elongation, induces spherical morphology and ultimately kills bacteria. We describe here a new mecillinam-resistant mutant of Escherichia coli, the lov mutant. It possesses active PBP2, as evidenced by its rod shape in the absence of mecillinam (but not in its presence), its ability to filament when septation is inhibited, and its penicillin-binding ability. The lov mutant grows slowly but seems to regulate its macromolecular parameters properly: cell volume, RNA content (ribosome concentration), and DNA content are appropriate for the growth rate, and the growth yield is identical to that of wild type. The lov mutation is located at 41 min on the E.coli genetic map and is recessive. Certain rpsL (StrR) mutations suppress the lov mutant's mecillinam resistance. The allele specificity of the suppression suggests that the lov gene product may interact directly with the ribosomes. The lov gene product thus seems to define a link between PBP2 (the mecillinam target) and the ribosomes; we propose that this link is involved in transmitting information on the growth rate (ribosome concentration) to the peptidoglycan synthesizing apparatus.
Bouloc
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Institut Jacques Monod, Centre National de la Recherche Scientifique, Université Paris, France.
Jaffé
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D'Ari
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D000217:Acyltransferases / Q000235:genetics*; D000560:Amdinocillin / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins; D000242:Cyclic AMP / Q000378:metabolism; D003864:Depression, Chemical; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006602:Hexosyltransferases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan / Q000096:biosynthesis*; D010458:Peptidyl Transferases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000378:metabolism; D000091243:Ribosomal Protein S9; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; D011953:Receptors, Cyclic AMP; D000091243:Ribosomal Protein S9; D012269:Ribosomal Proteins; C000717190:RpsI protein, E coli; C034212:ribosomal protein S12; D000242:Cyclic AMP; D000217:Acyltransferases; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D000560:Amdinocillin