title: Activation mechanism of thiol protease precursor from broiler chicken specific Staphylococcus aureus strain CH-91.
abstract: Staphylococcus aureus strain CH-91 isolated from chicken dermatitis lesions produces large quantities of thiol protease implicated in disease formation. Observed overproduction requires efficient activation of the protease precursor which mechanism is studied here in detail. Wild type and mutant precursor forms are expressed in E. coli to test different hypotheses on the activation process. It is demonstrated that wild type precursor undergoes rapid autocatalytic processing whereas proteolytically inactive catalytic triad cysteine mutant (C(249)A) of the precursor is stable, but can be processed by minute quantities of active protease. It is concluded that limited intramolecular proteolysis is mainly responsible for efficient activation but, a positive feedback loop also contributes to the process. Both activation pathways allow efficient production of mature extracellular thiol protease, a putative virulence factor specific for avian strains of S. aureus.
authors.affiliation: Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland. wladykab@interia.pl
authors.forename: Benedykt
authors.initials: B
authors.lastname: Wladyka
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Dubin
authors.forename: Adam
authors.initials: A
authors.lastname: Dubin
mesh_terms: D000818:Animals; D002645:Chickens; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D037521:Virulence Factors; D003546:Cysteine Endopeptidases