title: Extracellular proteases modify cell wall turnover in Bacillus subtilis.
abstract: The rate of turnover of peptidoglycan in exponentially growing cultures of Bacillus subtilis was observed to be sensitive to extracellular protease. In protease-deficient mutants the rates of cell wall turnover were greater than that of wild-type strain 168, whereas hyperprotease-producing strains exhibited decreased rates of peptidoglycan turnover. The rate of peptidogylcan turnover in a protease-deficient strain was decreased when the mutant was grown in the presence of a hyperprotease-producing strain. The addition of phenylmethylsulfonyl fluoride, a serine protease inhibitor, to cultures of hyperprotease-producing strains increased their rates of cell wall turnover. Isolated cell walls of all protease mutants contained autolysin levels equal to or greater than that of wild-type strain 168. The presence of filaments, or cells with incomplete septa, was observed in hyperprotease-producing strains or when a protease-deficient strain was grown in the presence of subtilisin. The results suggest that the turnover of cell walls in B. subtilis may be regulated by extracellular proteases.
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D001433:Bacteriolysis; D002458:Cell Fractionation; D002473:Cell Wall / Q000378:metabolism; D009154:Mutation; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D010457:Peptidoglycan / Q000378:metabolism*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D013381:Subtilisins / Q000494:pharmacology
chemical_list: D010457:Peptidoglycan; D010664:Phenylmethylsulfonyl Fluoride; D010447:Peptide Hydrolases; D013381:Subtilisins; D009238:N-Acetylmuramoyl-L-alanine Amidase