5cac
From Proteopedia
REFINED STRUCTURE OF HUMAN CARBONIC ANHYDRASE II AT 2.0 ANGSTROMS RESOLUTION
Overview
The structure of human erythrocytic carbonic anhydrase II has been refined by constrained and restrained structure-factor least-squares refinement at 2.0 A resolution. The conventional crystallographic R value is 17.3%. Of 167 solvent molecules associated with the protein, four are buried and stabilize secondary structure elements. The zinc ion is ligated to three histidyl residues and one water molecule in a nearly tetrahedral geometry. In addition to the zinc-bound water, seven more water molecules are identified in the active site. Assuming that Glu-106 is deprotonated at pH 8.5, some of the hydrogen bond donor-acceptor relations in the active site can be assigned and are described here in detail. The O gamma 1 atom of Thr-199 donates its proton to the O epsilon 1 atom of Glu-106 and can function as a hydrogen bond acceptor only in additional hydrogen bonds.
About this Structure
5CAC is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Refined structure of human carbonic anhydrase II at 2.0 A resolution., Eriksson AE, Jones TA, Liljas A, Proteins. 1988;4(4):274-82. PMID:3151019 Page seeded by OCA on Sun May 4 22:32:26 2008
