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

Abstract

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.

Molecular Characterization of a Novel Fibronectin-binding Protein of Streptococcus pyogenesStrains Isolated from Toxic Shock-like Syndrome Patients

“…Jaffe et al (8) reported that a highly homologous repeat domain in protein F2 is the main Fn-binding region when compared with that of protein F1. The present results showed that the putative Fn-binding domain of FbaB was highly conserved at the C-terminal region (Fig.…”

“…It has been demonstrated that several surface proteins have binding abilities to human host proteins, such as fibronectin (Fn) (1), laminin (2), plasmin (3), collagen (4), immunoglobulins (5), and C4b (6). Fn-binding proteins of GAS have also been reported to be adhesins and invasins, including protein F1/SfbI (1, 7), protein F2 (8), SfbII/ SOF (9, 10), PFBP (11), and Fba (renamed FbaA) (12). It is interesting to note that each Fn-binding protein is distributed in a particular group of M serotype (7,12,13), and highly virulent GAS strains possess one or more Fn-binding proteins.…”

Streptococcus pyogenes prtFII, but not sfbI, sfbII or fbp54, is represented more frequently among invasive-disease isolates of tropical Australia

“…In S. pyogenes, adherence could be mediated by different surface exposed proteins, which include among others, fibronectin binding proteins (FBPs) [7][8][9][10][11][12]. Four FBPs (SfbI, OF, PrtFII and Fbp54) have been extensively studied.…”

Immunological response mounted by Aboriginal Australians living in the Northern Territory of Australia against Streptococcus pyogenes serum opacity factor The GenBank accession numbers for the sequences reported in this paper are AF367011 (sof VT3.2), AF367012 (sof VT3.1), AF367013 (sof VT2.2), AF367014 (sof VT21), AF367015 (sof VT37.1) and AF367016 (sof 13).

“…Group A streptococci possess a number of surface adhesins capable of interacting with the extracellular host protein fibronectin (Courtney et al, Downloaded from www.microbiologyresearch.org by IP: 54.191.190.102 On: Sat, 12 May 2018 15:00:43 C. M. GILLEN and OTHERS 1996 ;Jaffe et al, 1996 ;Kreikemeyer et al, 1995 ;Talay et al, 1992 ;Rocha & Fischetti, 1999 ;Hanski & Caparon, 1992), an interaction which has been shown to play a major role in the adherence of the streptococcal cell to the epithelial cells of the host (Talay et al, 1992 ;Courtney et al, 1996 ;Molinari et al, 1997). The streptococcal serum opacity factor (SOF ; SfbII) is a large extracellular and surface-bound protein of group A streptococci which is capable of binding fibronectin (Rakonjac et al, 1995 ;Kreikemeyer et al, 1999).…”