title: Structure, refinement, and function of carbonic anhydrase isozymes: refinement of human carbonic anhydrase I.
abstract: The structure of human erythrocyte carbonic anhydrase I has been refined to a final R value of 19% to 2-A resolution by a combination of least squares refinement and model fitting in a three-dimensional graphics display. About 300 solvent atoms have been located bound to the protein molecule. An interesting hydrogen bond network involving Zn2+, the liganded solvent, side chain groups of Thr-199, Glu-106, Thr-7, and His-64 through two solvent molecules have been found that may be important for the catalytic mechanism of the carbonic anhydrase.
mesh_terms: D002256:Carbonic Anhydrases / Q000097:blood*; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008024:Ligands; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D014961:X-Ray Diffraction; D015032:Zinc / Q000032:analysis
chemical_list: D007527:Isoenzymes; D008024:Ligands; D002256:Carbonic Anhydrases; D015032:Zinc