Close-up of the C-terminal domain potential ligand binding pocket. The main chain of OspA is shown as a light-blue ribbon; residues forming the charge trio (Arg-139, Glu-160, and Lys-189) or lining the 34-Å3 cavity (Leu-167, Leu-178, Leu-187, Phe-237, and Ile-243) are shown in colors representative of side-chain type. The cavity, represented in green, was calculated by using the University of Groningen biomol suite. The figure was generated with setor (21).