FIGURE 5.
High resolution (1.9 Å) crystal structure of VahC. A, crystal structure of VahC (PDB entry 4FML) shown as a schematic diagram. Secondary structural elements (α-helices; β, β-strands) are shown and numbered in succession. Adjacent to the VahC structure is an expanded view of the active site with the important binding/catalytic residues shown in stick format. Motif 1 residues are in violet, motif 2 residues are in orange, motif 3 residues are in magenta, and the proposed critical residues of the active site loop are in yellow. B, structural comparison of VahC (green) with SpvB (PDB entry 2GWM; yellow) based on an iterative three-dimensional alignment of protein backbone Cα atoms. C, structural comparison of VahC (green) with ι-toxin catalytic domain, Ia (PDB entry 1GIQ; magenta) based on an iterative three-dimensional alignment of protein backbone Cα atoms. The structural differences are highlighted by orange arrows.