Crystal structure of human erythrocyte carbonic anhydrase B. Three-dimensional structure at a nominal 2.2-A resolution

摘要: The three-dimensional structure of carbonic anhydrase B (EC 4,2,1,1; carbonate hydro-lyase) from human erythrocytes has been determined to high resolution. Parallel and antiparallel pleated sheet makes up the predominant secondary enzyme. tertiary is unique for its folding very similar isoenzyme, erythrocyte C. essential metal ion, zinc, firmly bound enzyme through three histidyl ligands located at bottom a 12-A deep conical cavity. zinc are involved in number hydrogen bond formations with residues immediate vicinity active site Some similarities differences sidechain orientation topography two isoenzymes also discussed.