Complementation of divergent mga genes in group A Streptococcus.
The gene (mga4) encoding the positive regulatory protein, Mga4, was cloned and sequenced from an M type 4 strain (AP4) of Streptococcus pyogenes. The deduced amino acid (aa) sequence of this "divergent Mga' shows 88% identity to the prototype Mga1 in its N-terminal half, which contains all three of the predicted helix-turn-helix domains. However, one of the predicted receiver domains of Mga1, which is at its C terminus, is not conserved in the Mga4 aa sequence. Nevertheless, a mutation in mga1 was found to be complemented for activation of the gene encoding M protein (emm) by mga4 in trans. This suggests that the aa residues of the C-terminal predicted receiver domain are not critical for activation of emm transcription.
Andersson
G
G
Department of Microbiology, Lund University, Sweden.
McIver
K
K
Hedén
L O
LO
Scott
J R
JR
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D005798:Genes, Bacterial / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D008969:Molecular Sequence Data; D013297:Streptococcus pyogenes / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; C102187:Mga4 protein, Streptococcus pyogenes; D015534:Trans-Activators; C068267:mry protein, Streptococcus pyogenes