title: Degradation of extracytoplasmic catalysts for protein folding in Bacillus subtilis.
abstract: The general protein secretion pathway of Bacillus subtilis has a high capacity for protein export from the cytoplasm, which is exploited in the biotechnological production of a wide range of enzymes. These exported proteins pass the membrane in an unfolded state, and accordingly, they have to fold into their active and protease-resistant conformations once membrane passage is completed. The lipoprotein PrsA and the membrane proteins HtrA and HtrB facilitate the extracytoplasmic folding and quality control of exported proteins. Among the native exported proteins of B. subtilis are at least 10 proteases that have previously been implicated in the degradation of heterologous secreted proteins. Recently, we have shown that these proteases also degrade many native membrane proteins, lipoproteins, and secreted proteins. The present studies were therefore aimed at assessing to what extent these proteases also degrade extracytoplasmic catalysts for protein folding. To this end, we employed a collection of markerless protease mutant strains that lack up to 10 different extracytoplasmic proteases. The results show that PrsA, HtrA, and HtrB are indeed substrates of multiple extracytoplasmic proteases. Thus, improved protein secretion by multiple-protease-mutant strains may be related to both reduced proteolysis and improved posttranslocational protein folding and quality control.
authors.affiliation: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Laxmi
authors.initials: L
authors.lastname: Krishnappa
authors.forename: Carmine G
authors.initials: CG
authors.lastname: Monteferrante
authors.forename: Jolanda
authors.initials: J
authors.lastname: Neef
authors.forename: Annette
authors.initials: A
authors.lastname: Dreisbach
authors.forename: Jan Maarten
authors.initials: JM
authors.lastname: van Dijl
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D008074:Lipoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D017510:Protein Folding; D059748:Proteolysis; D012697:Serine Endopeptidases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; C082160:prsA protein, bacteria; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C419211:YkdA protein, Bacillus subtilis; C419213:YvtA protein, Bacillus subtilis