Mry, a trans-acting positive regulator of the M protein gene of Streptococcus pyogenes with similarity to the receptor proteins of two-component regulatory systems.
In the Streptococcus pyogenes M6 strain D471, an insertion of the conjugative transposon Tn916 into a region 2 kb upstream of the promoter of emm6 (the structural gene for the M protein) rendered the strain M negative (M. G. Caparon and J. R. Scott, Proc. Natl. Acad. Sci. USA 84:8677-8681, 1987). In the present work, we show that this insertion mutation, mry-1, is 244 bp upstream of an open reading frame encoding a protein we call Mry. This protein is visible on a gel after transcription and translation in vitro. We have developed a technique for complementation analysis in S. pyogenes and have used it to show that the wild-type mry gene is dominant to two mutant alleles. This dominance indicates that Mry acts in trans as a positive regulator of the emm6 gene. The translated DNA sequence of mry has two regions of similarity to the motif common to the receptor protein of two-component regulatory systems. In addition, the N terminus of Mry has two regions resembling a helix-turn-helix motif. Mry does not appear to be a global regulator of virulence determinants in the group A streptococcus because there is no effect of the mry-1 mutation on production of the hyaluronic acid capsule or streptokinase.
Perez-Casal
J
J
Microbiology and Immunology Department, Emory University Health Sciences Center, Atlanta, Georgia 30322.
Caparon
M G
MG
Scott
J R
JR
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005799:Genes, Dominant; D005809:Genes, Regulator / Q000502:physiology*; D008969:Molecular Sequence Data; D010957:Plasmids; D014176:Protein Biosynthesis; D012689:Sequence Homology, Nucleic Acid; D013297:Streptococcus pyogenes / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; C014689:streptococcal M protein; C068267:mry protein, Streptococcus pyogenes