Protein F2, a novel fibronectin-binding protein from Streptococcus pyogenes, possesses two binding domains

Mol Microbiol. 1996 Jul;21(2):373-84. doi: 10.1046/j.1365-2958.1996.6331356.x.


Binding of the group A streptococcus (GAS) to respiratory epithelium is mediated by the fibronectin (Fn)-binding adhesin, protein F1. Previous studies have suggested that certain GAS strains express Fn-binding proteins that are different from protein F1. In this study, we have cloned, sequenced, and characterized a gene (prtF2) from GAS strain 100076 encoding a novel Fn-binding protein, termed protein F2. Insertional inactivation of prtF2 in strain 100076 abolishes its high-affinity Fn binding. prtF2-related genes exist in most GAS strains that lack prtF1 (encoding protein F1) but bind Fn with high affinity. These observations suggest that protein F2 is a major Fn-binding protein in GAS. Protein F2 is highly homologous to Fn-binding proteins from Streptococcus dysgalactiae and Streptococcus equisimilis, particularly in its carboxy-terminal portion. Two domains are responsible for Fn binding by protein F2. One domains (FBRD) consists of three consecutive repeats, whereas the other domain (UFBD) resides on a non-repeated stretch of approximately 100 amino acids and is located 100 amino acids aminoterminal of FBRD. Each of these domains is capable of binding Fn when expressed as a separate protein. In strain 100076, protein F2 activity is regulated in response to alterations in the concentration of atmospheric oxygen.

Publication types

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

MeSH terms

  • Adhesins, Bacterial*
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Binding Sites / genetics
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • Cloning, Molecular
  • DNA Primers / genetics
  • DNA, Bacterial / genetics
  • Fibronectins / metabolism*
  • Genes, Bacterial
  • Molecular Sequence Data
  • Molecular Structure
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Repetitive Sequences, Nucleic Acid
  • Sequence Homology, Amino Acid
  • Streptococcus pyogenes / classification
  • Streptococcus pyogenes / genetics*
  • Streptococcus pyogenes / metabolism*


  • Adhesins, Bacterial
  • Bacterial Proteins
  • Carrier Proteins
  • DNA Primers
  • DNA, Bacterial
  • Fibronectins
  • Peptide Fragments
  • fibronectin-binding proteins, bacterial

Associated data

  • GENBANK/U31980