Size variation in group A streptococcal M protein is generated by homologous recombination between intragenic repeats.
M protein, a major surface protein and virulence factor for the group A streptococcus, exhibits extraordinary size variation in strains of the same serotype (Fischetti et al. 1985). RNA sequence analysis of spontaneous M protein size variants shows that deletion mutations arise in a single strain by homologous recombination events between intragenic tandem repeats. Similar deletion and duplication events also occur in serial streptococcal isolates from a single patient and among related strains in a recent outbreak. We discuss how homologous recombination events can lead to the generation of antigenic variation.
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics*; D005075:Biological Evolution; D002352:Carrier Proteins; D004262:DNA Restriction Enzymes; D005796:Genes; D005798:Genes, Bacterial; D014644:Genetic Variation; D009154:Mutation; D012091:Repetitive Sequences, Nucleic Acid; D013297:Streptococcus pyogenes / Q000235:genetics*
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D004262:DNA Restriction Enzymes