Fc-receptor and M-protein genes of group A streptococci are products of gene duplication.
The partial nucleotide sequence for an Fc-receptor gene from an M-type 76 group A streptococcus was determined. DNA sequence analysis revealed considerable sequence similarity between the Fc-receptor and M-protein genes in their proposed promoter regions, signal sequences, and 3' termini. Additional analysis indicated that the deduced Fc-receptor protein contains a proline-rich region and membrane anchor region highly similar to that of M protein. In view of these results, we postulated that Fc-receptor and M-protein genes of group A streptococci are the products of gene duplication from a common ancestral gene. It is proposed that DNA sequence similarity between these two genes may allow for extragenic homologous recombination as a means of generating antigenic diversity in these two surface proteins.
Heath
D G
DG
Department of Microbiology, University of Minnesota, Minneapolis 55455.
Cleary
P P
PP
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins; D005796:Genes; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D010957:Plasmids; D021382:Protein Sorting Signals / Q000235:genetics; D011961:Receptors, Fc / Q000235:genetics*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000276:immunology
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D021382:Protein Sorting Signals; D011961:Receptors, Fc; C014689:streptococcal M protein