Publication Abstract from PubMed
Decorin-binding protein A (DbpA) of Borrelia burgdorferi mediates bacterial adhesion to heparin and dermatan sulfate associated with decorin. Lysines K82, K163, and K170 of DbpA are known to be important for in vitro interaction with decorin, and the DbpA structure, initially solved by nuclear magnetic resonance (NMR) spectroscopy, suggests these lysine residues colocalize in a pocket near the C-terminus of the protein. In the current study, we solved the structure of DbpA from B. burgdorferi strain 297 using X-ray crystallography and confirmed the existing NMR structural data. In vitro binding experiments confirmed that recombinant DbpA proteins with mutations in K82, K163, or K170 did not bind decorin, which was due to an inability to interact with dermatan sulfate. Most importantly, we determined that the in vitro binding defect observed upon mutation of K82, K163, or K170 in DbpA also lead to a defect during infection. The infectivity of B. burgdorferi expressing individual dbpA lysine point mutants was assessed in mice challenged via needle inoculation. Murine infection studies showed that strains expressing dbpA with mutations in K82, K163, and K170 were significantly attenuated and could not be cultured from any tissue. Proper expression and cellular localization of the mutated DbpA proteins was examined and NMR spectroscopy determined that the mutant DbpA proteins were structurally similar to wild-type DbpA. Taken together, these data showed that lysines K82, K163, and K170 potentiate the binding of DbpA to dermatan sulfate and that interaction(s) mediated by these lysines are essential for B. burgdorferi murine infection.
Identification of Lysine Residues in the Borrelia burgdorferi DbpA Adhesin Required for Murine Infection.,Fortune DE, Lin YP, Deka RK, Groshong AM, Moore BP, Hagman KE, Leong JM, Tomchick DR, Blevins JS Infect Immun. 2014 May 19. pii: IAI.02036-14. PMID:24842928[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
