Antigenic diversity within a family of M proteins from group A streptococci: evidence for the role of frameshift and compensatory mutations

Gene. 1994 Jun 24;144(1):25-30. doi: 10.1016/0378-1119(94)90198-8.


The genes (emm) encoding M proteins, from isolates of group-A streptococci (GAS) serotyped as M52, M53, M80 and M nontypeable (MNT; serologically related to M53 and M80), were examined. Characterization of emm from these GAS revealed some discrepancies with serotyping, illustrating the difficulty in serotype determination when cross-reactions occur. DNA sequences corresponding to the N-terminal region of M proteins from the isolates showed considerable similarity both in the hypervariable region and the repeat regions. We propose that these serotypes form a family of closely related M types. Frameshift mutations in the hypervariable region followed by a corrective (compensatory) frameshift were observed. This may be an effective mechanism for generating antigenic diversity in the M protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • Bacterial Outer Membrane Proteins*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • Base Sequence
  • Carrier Proteins*
  • DNA, Bacterial
  • Epitopes / genetics*
  • Frameshift Mutation*
  • Molecular Sequence Data
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Streptococcus pyogenes / genetics*
  • Streptococcus pyogenes / immunology


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

Associated data

  • GENBANK/L27093
  • GENBANK/L27094
  • GENBANK/L27095
  • GENBANK/L27096
  • GENBANK/L27097
  • GENBANK/L27098
  • GENBANK/L27099