Structure of bovine carbonic anhydrase II at 1.95 Ã… resolution
Structure of bovine carbonic anhydrase II at 1.95 Ã… resolution
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DOI：
10.1107/s0907444904003166
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发表时间：
2004-04-01
影响因子：
2.2
通讯作者：
Tanaka, N
中科院分区：
文献类型：
--
作者：
Saito, R;Sato, T;Tanaka, N
碳酸酐酶（carbonic anhydrase，CA）是一种含锌的酶，催化CO2可逆水合为HCO3-。在真核生物中，该酶在多种生理功能中发挥作用，包括中间代谢中CO2和HCO3-之间的相互转化，促进CO2的扩散，pH稳态和离子转运。牛碳酸酐酶II（BCA II）的结构已被确定的分子置换，并通过模拟退火和个人的B因子细化细化到1.95埃的分辨率。BCA II结构的最终R因子为19.4%。BCA II具有与在人CA II中观察到的相似的C-末端结结构。它含有一个锌离子在活性部位协调三个组氨酸和一个假定的水分子在一个四面体的几何形状。BCA II的结构揭示了一个可能的替代质子线途径，不同于HCA II。
Carbonic anhydrase (CA) is a zinc-containing enzyme that catalyzes the reversible hydration of CO2 to HCO3-. In eukaryotes, the enzyme plays a role in various physiological functions, including interconversion between CO2 and HCO3- in intermediary metabolism, facilitated diffusion of CO2, pH homeostasis and ion transport. The structure of bovine carbonic anhydrase II (BCA II) has been determined by molecular replacement and refined to 1.95 Angstrom resolution by simulated-annealing and individual B-factor refinement. The final R factor for the BCA II structure was 19.4%. BCA II has a C-terminal knot structure similar to that observed in human CA II. It contains one zinc ion in the active site coordinated to three histidines and one putative water molecule in a tetrahedral geometry. The structure of BCA II reveals a probable alternative proton-wire pathway that differs from that of HCA II.