title: Specific binding of the activator Mga to promoter sequences of the emm and scpA genes in the group A streptococcus.
abstract: Transcription of the surface-associated virulence factors of the group A streptococcus (GAS) Streptococcus pyogenes, M protein (emm) and the C5a peptidase (scpA), is activated by a protein called Mga (formerly Mry or VirR). To determine whether Mga binds directly to the promoters of the genes it regulates, a protein resulting from the fusion of Mga to the C-terminal end of maltose-binding protein was purified from Escherichia coli. Specific binding to the promoter regions of the scpA and emm alleles of the type M6 GAS strain JRS4 was demonstrated by electrophoresis of the DNA-protein complex. Competition studies showed that the region upstream of scpA bound MBP-Mga with a slightly higher affinity than did the region upstream of emm. DNase I protection experiments identified a single 45-bp binding site immediately upstream of and overlapping the -35 region of both promoters. Sequences homologous to the protected regions were found in the promoters of many emm, scp, and emm-like genes from strains of different serotypes of GAS, and a consensus Mga binding site was deduced.
authors.affiliation: Department of Microbiology and Immunology, Rollins Research Center, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: McIver
authors.forename: A S
authors.initials: AS
authors.lastname: Heath
authors.forename: B D
authors.initials: BD
authors.lastname: Green
authors.forename: J R
authors.initials: JR
authors.lastname: Scott
mesh_terms: D018528:ATP-Binding Cassette Transporters; D018829:Adhesins, Bacterial; D000483:Alleles; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000235:genetics; D016384:Consensus Sequence / Q000235:genetics; D004269:DNA, Bacterial / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial / Q000235:genetics; D058619:Maltose-Binding Proteins; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D016415:Sequence Alignment; D013297:Streptococcus pyogenes / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C461599:maltose transport system, E coli; C014689:streptococcal M protein; C068267:mry protein, Streptococcus pyogenes; D010450:Endopeptidases; C053088:C5a peptidase