Insertional inactivation of virR in Streptococcus pyogenes M49 demonstrates that VirR functions as a positive regulator of ScpA, FcRA, OF, and M protein

• Published in: FEMS microbiology letters 1995-04, Vol.128 (1), p.45-51
• Main Authors: Mclandsborough, Lynne A., Cleary, P. Patrick
• Format: Article
• Language: English
• Subjects: Antigens, Bacterial; Bacterial Outer Membrane Proteins; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; Carrier Proteins; Gene Expression Regulation, Bacterial; Genes, Bacterial - physiology; Mutagenesis, Insertional; Opacity factor; Peptide Hydrolases - biosynthesis; Peptide Hydrolases - genetics; Streptococcus pyogenes; Streptococcus pyogenes - genetics; virR
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.1995.tb07498.x

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 (indétectable 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.