Thus, we quantitatively characterized the decorin- and dermatan sulfate-binding activities of three DbpA variants, i.e. DbpAPBr, DbpAVS461 and DbpAN40-D10/E9, which together represent the three major Lyme disease spirochete genospecies, and generated a set of isogenic B. burgdorferi strains derived from a B. burgdorferi ΔdbpBA mutant that expressed each of these variants. The gene discussed is YBX3; the disease is Lyme disease.