REFINED STRUCTURE OF HUMAN CARBONIC ANHYDRASE-II AT 2.0-A RESOLUTION
REFINED STRUCTURE OF HUMAN CARBONIC ANHYDRASE-II AT 2.0-A RESOLUTION
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DOI：
10.1002/prot.340040406
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发表时间：
1988-01-01
影响因子：
2.9
通讯作者：
LILJAS, A
中科院分区：
文献类型：
--
作者：
ERIKSSON, AE;JONES, TA;LILJAS, A
人红细胞碳酸酐酶II的结构在2.0 . ang下进行了约束和约束结构因子最小二乘细化。决议。常规晶体学R值为17.3%。在167个与蛋白质相关的溶剂分子中，有4个是埋藏和稳定的二级结构元素。锌离子以接近四面体的几何形状连接到三个组氨酸残基和一个水分子上。除了锌结合水外，在活性位点还发现了另外7个水分子。假设Glu-106在pH 8.5下去质子化，活性位点的一些氢键供体-受体关系可以被分配，并在这里详细描述。O.gamma。Thr-199的1个原子把它的质子给了o。只有在附加的氢键中才能作为氢键受体。
The structure of human erythrocytic carbonic anhydrase II has been refined by constrained and restrained structure-factor least-squares refinement at 2.0 .ANG. 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.