Figure 5.

Stereoview of the EcCM active site with bound transition state analog (pink) (18), showing the positions of the catalytic residues (blue) and the first and second sphere residues (yellow) that had highly restricted sequence requirements in active clones from the MjCM′ H1/H2/H3 library. The amino acid at position 84 forms a hydrogen bond with the tertiary carboxylate of the bound inhibitor (pink), while residues 14 and 85 are in van der Waals contact with the ligand. Amino acids at positions 15 and 18 help position active site residues Arg-51 and Arg-28, respectively. Image was created by using molscript (39) and RASTER3D (40).