4CAC

REFINED STRUCTURE OF HUMAN CARBONIC ANHYDRASE II AT 2.0 ANGSTROMS RESOLUTION

Summary for 4CAC

• Entry DOI: 10.2210/pdb4cac/pdb
• Descriptor: CARBONIC ANHYDRASE FORM C, ZINC ION (3 entities in total)
• Functional Keywords: lyase(oxo-acid)
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm : P00918
• Total number of polymer chains: 1
• Total formula weight: 29223.27

Authors

Lindahl, M.,Habash, D.,Harrop, S.,Helliwell, D.R.,Liljas, A. (deposition date: 1991-09-05, release date: 1994-01-31, Last modification date: 2024-02-28)

Primary citation

Eriksson, A.E.,Jones, T.A.,Liljas, A.
Refined structure of human carbonic anhydrase II at 2.0 A resolution.
Proteins, 4:274-282, 1988

PubMed Abstract: 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.

PubMed: 3151019
DOI: 10.1002/prot.340040406

Experimental method

X-RAY DIFFRACTION (2.2 Å)