Protein F2, a novel fibronectin-binding protein from Streptococcus pyogenes, possesses two binding domains.
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.
Jaffe
J
J
Department of Clinical Microbiology, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
Natanson-Yaron
S
S
Caparon
M G
MG
Hanski
E
E
D018829:Adhesins, Bacterial; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D005353:Fibronectins; D010446:Peptide Fragments; C078635:fibronectin-binding proteins, bacterial