title: Attenuated expression of the mga virulence regulon in an M serotype 50 mouse-virulent group A streptococcal strain.
abstract: The attenuated expression of virulence genes found in a group A streptococcal strain that is naturally pathogenic for mice was postulated to result from a defect in the strain's multigene regulator, Mga. The sequence of the mga gene reveals three amino acid changes in the gene product that might affect protein function. The defect in the mga gene was complemented by providing either the closely similar mga4 allele or a more divergent mga1 allele in trans. Complementation increased the amount of emm50 transcript and the quantity of surface-extractable M protein, restoring virulence function.
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Yung
authors.forename: K S
authors.initials: KS
authors.lastname: McIver
authors.forename: J R
authors.initials: JR
authors.lastname: Scott
authors.forename: S K
authors.initials: SK
authors.lastname: Hollingshead
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D018085:Regulon; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; C068267:mry protein, Streptococcus pyogenes