PEDS Advance Access published online on May 7, 2008
Protein Engineering Design and Selection, doi:10.1093/protein/gzn025
The Yersinia adhesin YadA binds to a collagenous triple-helical conformation but without sequence specificity
1Macromolecular X-ray Crystallography Group, Structural Biology and Biophysics 2Genetics, Department of Biological and Environmental Sciences 3Department of Bacteriology and Immunology, Haartman Institute and Laboratory Diagnostics, Helsinki University Central Hospital 4Neuroscience Center, Helsinki University, FI-00014 Helsinki, Finland 5 National Graduate School in Informational and Structural Biology, Åbo Akademi University, FI-20520 Turku, Finland 6Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA
8 To whom correspondence should be addressed. E-mail: adrian.goldman{at}helsinki.fi
The Yersinia adhesin A (YadA) is a collagen-binding trimeric autotransporter of Yersinia enterocolitica, an enteropathogen that causes a range of gastroenteric and systemic diseases, and YadA is essential for Y. enterocolitica virulence. Although previous studies suggest a specific binding site in collagen for YadA, we found that recombinant YadA binds to both major cyanogen bromide fragments of collagen type II and the collagen-like model peptide (Pro-Hyp-Gly)10 [(POG)10]. To further characterise the YadA–collagen interaction, we investigated the binding of YadA to (POG)10 and three other model peptides, (Pro-Pro-Gly)10 which lacks the hydroxyl groups of (POG)10, T3-785 which contains a stretch of the collagen type III sequence and Gly– which is similar to (POG)10 but lacks the central glycine. All the peptides except Gly– adopt a collagen-like triple-helical conformation at room temperature. All three triple-helical peptides bound to YadA, with (POG)10 being the tightest, whereas binding of Gly– was hardly detectable. The affinity of (POG)10 for YadA was 0.28 µM by isothermal titration calorimetry and 0.17 µM by surface plasmon resonance (SPR), similar to that of collagen type I. Our results show that a collagen-like triple-helical conformation, strengthened by the presence of hydroxyproline residues, is both necessary and sufficient for YadA binding.
Keywords: adhesion/collagen/triple-helical peptide/YadA/Yersinia enterocolitica
Received April 10, 2008; revised April 10, 2008; accepted April 11, 2008.
7 Present address: Medicity Research Laboratory, University of Turku, FI-20520 Turku, Finland and National Public Health Institute, FI-20520 Turku, Finland.