title: Mutagenesis of the carboxy terminal protease CtpA decreases desiccation tolerance in Rhizobium leguminosarum.
abstract: To better understand the role of proteases in Rhizobium leguminosarum biovar viciae, a gene with homology to the carboxy-terminal protease (CtpA), which belongs to a novel group of serine proteases, was studied. The ctpA gene was cloned and mutated using allelic exchange and a gusA reporter gene was used to study ctpA expression. Mutational analysis shows that ctpA is critical for the viability of R. leguminosarum when cells are grown on complex semi-solid media but is dispensable when cells are grown in complex liquid media and that this is likely due to an increase in susceptibility to desiccation on semi-solid media. The ctpA mutant also displayed an increased sensitivity to detergents, indicating an alteration in the permeability of the cell envelope. This is the first characterization of a ctpA gene within the Rhizobiaceae and the first report of a ctpA mutant that exhibits an increased sensitivity to desiccation.
authors: Department of Biology, University of Regina, Regina, Canada.
authors: Kerrigan B
authors: KB
authors: Gilbert
authors: Elizabeth M
authors: EM
authors: Vanderlinde
authors: Christopher K
authors: CK
authors: Yost
mesh_terms: D020418:Algal Proteins; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D002268:Carboxypeptidases / Q000235:genetics* / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D003681:Dehydration; D003902:Detergents / Q000494:pharmacology; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D020043:Genes, Essential / Q000235:genetics; D017930:Genes, Reporter; D005966:Glucuronidase / Q000032:analysis / Q000235:genetics; D050296:Microbial Viability / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010539:Permeability; D043484:Proprotein Convertases / Q000235:genetics* / Q000502:physiology*; D016961:Rhizobium leguminosarum / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*
chemical_list: D020418:Algal Proteins; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003902:Detergents; D005966:Glucuronidase; D002268:Carboxypeptidases; D043484:Proprotein Convertases; C073491:photosystem II, D1 polypeptide carboxy-terminal processing protease