title: Insertional inactivation of virR in Streptococcus pyogenes M49 demonstrates that VirR functions as a positive regulator of ScpA, FcRA, OF, and M protein.
abstract: Several reports have shown that Streptococcus pyogenes strains which produce opacity factor (OF+) have diverged significantly from OF- serotypes. This study questions whether several surface proteins of an OF+ culture are regulated by the positive regulatory protein VirR, in a manner similar to OF- strains. Interruption of the virR region of an OF+ S. pyogenes (strain CS101, M type 49) was performed using a temperature-sensitive plasmid containing a fragment of virR. Interruption of the virR region produced cultures with undetectable amounts of M49 and ScpA proteins, and reduced the yield of FcRA protein. In addition, mutants had a significant reduction in detectable opacity factor. These results suggest that virR functions as a positive regulator of a variety of surface proteins in OF+ strains.
authors.affiliation: University of Minnesota, Minneapolis 55455, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: McLandsborough
authors.forename: P P
authors.initials: PP
authors.lastname: Cleary
mesh_terms: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D002352:Carrier Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000502:physiology*; D016254:Mutagenesis, Insertional; D010447:Peptide Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D013297:Streptococcus pyogenes / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C021908:opacity factor; C014689:streptococcal M protein; D010447:Peptide Hydrolases