Figure 4.

(A) A network of water molecules in the Hsp90 binding site. (B) W2 and W3 were predicted to be replaced by methane and methanol as most favorable probes. (C) In X-ray crystallographic ligands, W2 and W3 have been displaced by nitrile and methyl groups, respectively. (D) The best scoring probes corresponding to W1 and W4 were ammonia and methane, respectively. (E) In X-ray crystallographic ligands, W4 has been replaced by an ethyl group, but no reported examples were found for the displacement of W1 (it is not present in some structures but never overlaps with the ligand).