CYS 160; ;HIS 220;CYS 223(Zinc binding)
CYS 160;ASP 162;HIS 220;CYS 223(Zinc binding)
CYS 42;ASP 44;HIS 98;CYS 101(Zinc binding)
Solvent hydrogen isotope effects and anion inhibition of CO2 hydration catalysed by carbonic anhydrase from Pisum sativum.
The sulfhydryl groups of Cys 269 and Cys 272 are critical for the oligomeric state of chloroplast carbonic anhydrase from Pisum sativum.
Structure and mechanism of carbonic anhydrase.
X-RAY CRYSTALLOGRAPHY (1.93 ANGSTROMS) OF 108-328.
The active site architecture of Pisum sativum beta-carbonic anhydrase is a mirror image of that of alpha-carbonic anhydrases.
X-ray structure of beta-carbonic anhydrase from the red alga, Porphyridium purpureum, reveals a novel catalytic site for CO(2) hydration.
Crystal structure of the "cab"-type beta class carbonic anhydrase from the archaeon Methanobacterium thermoautotrophicum.
Carbonic anhydrase: new insights for an ancient enzyme.
Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity.
Kinetic characterization of wild-type and proton transfer-impaired variants of beta-carbonic anhydrase from Arabidopsis thaliana.
Chemical rescue of proton transfer in catalysis by carbonic anhydrases in the beta- and gamma-class.
Roles of the conserved aspartate and arginine in the catalytic mechanism of an archaeal beta-class carbonic anhydrase.
Examination of the role of Gln-158 in the mechanism of CO(2) hydration catalyzed by beta-carbonic anhydrase from Arabidopsis thaliana.
This enzyme belongs to the beta-carbonic anhydrase family. The catalytic zinc ion is ligated by two conserved cysteine residues and a conserved histidine, together with a conserved aspartate residue (Asp162 of 1ekj). However, in some structures, the aspartate residue is displaced, suggesting that this residue function as a switch of catalytic reaction (see [8]). According to the literature [4], [7], [8], [9] & [12], the catalytic reaction proceeds as follows: (1) A water molecule is bound to the cofactor zinc. (2) A proton of the substrate water is abstracted by a general base or proton shuttle residue (which transfers a proton to the solvent), or solvent, to generate the hydroxide. This role is probably played by Tyr205' from the adjacent chain (of 1ekj). (Asp162 may act as a general base, which deprotonates the water bound to the cofactor zinc ion.) (3) The hydroxide bound to zinc makes a nucleophilic attack on the carbon atom of another substrate, carbon dioxide (CO2), which is stabilized by Gln151' from the adjacent chain (of 1ekj). The nucleophile, the hydroxide, is also stabilized by Asp162. This reaction leads to the formation of the product, bicarbonate anion.