Protein F, a fibronectin-binding protein, is an adhesin of the group A streptococcus Streptococcus pyogenes.
Binding to fibronectin has been suggested to play an important role in adherence of the group A streptococcus Streptococcus pyrogenes to host epithelial cells; however, the identity of the streptococcal fibronectin receptor has been elusive. Here we demonstrate that the fibronectin-binding property of S. pyogenes is mediated by protein F, a bacterial surface protein that binds fibronectin at high affinity. The gene encoding protein F (prtF) produced a functional fibronectin-binding protein in Escherichia coli. Insertional mutagenesis of the cloned gene generated a mutation that resulted in the loss of fibronectin-binding activity. When this mutation was introduced into the S. pyrogenes chromosome by homologous recombination with the wild-type allele, the resulting strains no longer produced protein F and lost their ability to bind fibronectin. The mutation could be complemented by prtF introduced on a plasmid. Mutants lacking protein F had a much lower capacity to adhere to respiratory epithelial cells. These results demonstrate that protein F is an important adhesin of S. pyogenes.
Hanski
E
E
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110-1093.
Caparon
M
M
D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D006224:Cricetinae; D004848:Epithelium / Q000382:microbiology; D005353:Fibronectins / Q000378:metabolism; D005798:Genes, Bacterial; D066298:In Vitro Techniques; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D012137:Respiratory System / Q000382:microbiology; D015183:Restriction Mapping; D013297:Streptococcus pyogenes / Q000235:genetics / Q000472:pathogenicity*
D005353:Fibronectins; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic