Figure 5 - full size

 

Figure 5.
Figure 5. The structure of the active site of H64A-T200H HCA II crystallized at pH 9.3. His94, His96, and His 119 and the zinc-bound solvent, W262, are direct ligands of the zinc. The dotted red lines indicate plausible hydrogen-bonds. The distance from W262 to ND1 His200 is 3.1 Å, from W262 to OG1 Thr199 is 2.7 Å, fromW387 to ND1 His200 is 3.1 Å, from W387 to W363 is 2.8 Å and from W363 to ND2 Gln67 is 2.8 Å. Electron density (2F[o] - F[c]) contoured at 1.5 (blue) is shown for His200, Zn^2+, W262, W363, and W387. Superimposed on Ala64 is the in orientation of the side chain of the proton shuttle residue His64 of wild-type HCA II.

The above figure is reprinted by permission from John Wiley & Sons, Inc.: Proteins (2005, 61, 239-245) copyright 2005.