Size variation in group A streptococcal M protein is generated by homologous recombination between intragenic repeats

Mol Gen Genet. 1987 May;207(2-3):196-203. doi: 10.1007/BF00331578.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigens, Bacterial*
  • Bacterial Outer Membrane Proteins*
  • Bacterial Proteins / genetics*
  • Biological Evolution
  • Carrier Proteins*
  • DNA Restriction Enzymes
  • Genes*
  • Genes, Bacterial*
  • Genetic Variation
  • Mutation
  • Repetitive Sequences, Nucleic Acid
  • Streptococcus pyogenes / genetics*


  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • streptococcal M protein
  • DNA Restriction Enzymes