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Structural and functional analysis of the fibronectin‐binding protein FNE from Streptococcus equi spp. equi
Author(s) -
Tiouajni Mounira,
Durand Dominique,
Blondeau Karine,
Graille Marc,
Urvoas Agathe,
ValerioLepiniec Marielle,
Guellouz Asma,
AumontNicaise Magali,
Minard Philippe,
Tilbeurgh Herman
Publication year - 2014
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.13092
Subject(s) - streptococcus equi , pilus , peptide , streptococcus pyogenes , fibronectin , lim domain , chemistry , biology , microbiology and biotechnology , biophysics , biochemistry , bacteria , extracellular matrix , gene , genetics , transcription factor , escherichia coli , zinc finger , staphylococcus aureus
Streptococcus equi is a horse pathogen belonging to Lancefield group C. Infection by S. equi ssp. equi causes strangles, a serious and highly contagious disease of the upper respiratory tract. S. equi ssp. equi secretes a fibronectin (Fn)‐binding protein, FNE , that does not contain cell wall‐anchoring motifs. FNE binds to the gelatin‐binding domain ( GBD ) of Fn, composed of the motifs 6 F I 12 F II 789 F I . FNE lacks the canonical Fn‐binding peptide repeats observed in many microbial surface components recognizing adhesive matrix molecules. We found that the interaction between FNE and the human GBD is mediated by the binding of the disordered C‐terminal region (residues 208–262) of FNE to the 789 F I GBD subfragment. The crystal structure of FNE showed that it is similar to the minor pilus protein Spy0125 of Streptococcus pyogenes , found at the end of pilus polymers and responsible for adhesion. FNE and Spy0125 both have a superimposable internal thioester bond between highly conserved Cys and Gln residues. Small‐angle X‐ray scattering of the FNE – 789 F I complex provided a model that aligns the C‐terminal peptide of FNE with the E‐strands of the F I domains, adopting the β‐zipper extension model observed in previous structures of microbial surface components recognizing adhesive matrix molecule adhesion peptides bound to F I domains. Database The coordinates of the FNE–αREP3 complex have been deposited at the Protein Data Bank under the code 4PFG . Structured digital abstractGBD and FNE bind by isothermal titration calorimetry ( View interaction ) GBD 789FI and FNE bind by isothermal titration calorimetry ( View interaction ) FNE-CT and GBD 789FI bind by isothermal titration calorimetry ( View interaction ) GBD and FNE-CT bind by isothermal titration calorimetry ( View interaction ) FNE and GBD 789FI bind by molecular sieving ( View interaction ) FNE-CT binds to GBD 789FI by pull down ( View interaction ) FNE and GBD 789FI bind by x ray scattering ( View interaction ) GBD and FNE physically interact by fluorescence polarization spectroscopy ( View interaction ) collagen and GBD bind by fluorescence polarization spectroscopy ( View interaction )