Borrelia burgdorferi binds fibronectin through a tandem beta-zipper, a common mechanism of fibronectin binding in staphylococci, streptococci, and spirochetes.
BBK32 is a fibronectin-binding protein from the Lyme disease-causing spirochete Borrelia burgdorferi. In this study, we show that BBK32 shares sequence similarity with fibronectin module-binding motifs previously identified in proteins from Streptococcus pyogenes and Staphylococcus aureus. Nuclear magnetic resonance spectroscopy and isothermal titration calorimetry are used to confirm the binding sites of BBK32 peptides within the N-terminal domain of fibronectin and to measure the affinities of the interactions. Comparison of chemical shift perturbations in fibronectin F1 modules on binding of peptides from BBK32, FnBPA from S. aureus, and SfbI from S. pyogenes provides further evidence for a shared mechanism of binding. Despite the different locations of the bacterial attachment sites in BBK32 compared with SfbI from S. pyogenes and FnBPA from S. aureus, an antiparallel orientation is observed for binding of the N-terminal domain of fibronectin to each of the pathogens. Thus, these phylogenetically and morphologically distinct bacterial pathogens have similar mechanisms for binding to human fibronectin.
Raibaud
Sophie
S
Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
Schwarz-Linek
Ulrich
U
Kim
Jung Hwa
JH
Jenkins
Huw T
HT
Baines
Elizabeth R
ER
Gurusiddappa
Sivashankarappa
S
Höök
Magnus
M
Potts
Jennifer R
JR
D018829:Adhesins, Bacterial / Q000737:chemistry* / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D025065:Borrelia burgdorferi / Q000378:metabolism*; D002151:Calorimetry; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010843:Pichia / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013144:Spirochaetales / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000378:metabolism*; D013297:Streptococcus pyogenes / Q000378:metabolism*
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D005353:Fibronectins; D010455:Peptides; D011994:Recombinant Proteins; C078635:fibronectin-binding proteins, bacterial; C106209:p35 antigen, Borrelia