Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 64, Part 3 (March 2008)

protein structure communications

Acta Cryst. (2008). F64, 163-166 [ doi:10.1107/S1744309108002078 ]

A novel acetate-bound complex of human carbonic anhydrase II

P. A. Mazumdar, D. Kumaran, S. Swaminathan and A. K. Das

Abstract: The enzyme human carbonic anhydrase II (hCAII) crystallized in an acetate-bound complex belonging to space group P2₁2₁2₁, with unit-cell parameters a = 42.3, b = 71.8, c = 74.0 Å. The structure was solved by the molecular-replacement method and refined to an R value of 0.18 and an R_free of 0.21. The acetate molecule replaced the zinc-bound water molecule in the structure, differing from previous reports regarding the site of acetate binding. This mode of binding disrupts the hydrogen-bonded solvent network required for activity of the enzyme. This mode of inhibitor binding is a novel one that has not been observed previously.

PDB reference: 1xeg

Keywords: carbonic anhydrase II; acetate binding.