The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 angstrom
The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 angstrom
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DOI：
10.1126/science.272.5265.1136
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发表时间：
1996-05-24
期刊：
影响因子：
56.9
通讯作者：
Yoshikawa, S
中科院分区：
文献类型：
--
作者：
Tsukihara, T;Aoyama, H;Yoshikawa, S
牛心脏细胞色素c氧化酶的晶体结构在2.8埃分辨率下，R值为19.9%，显示出13个亚基，每个亚基彼此不同，5个磷脂酰乙醇胺，3个磷脂酰甘油和2个胆酸盐，2个血红素A，3个铜，1个镁和1个锌。在二聚体的3606个氨基酸残基中，3560个氨基酸残基已经通过改进收敛到合理的结构。一个氢键系统，包括血红素A的丙酸酯（血红素a），肽骨架的一部分，和Cu-A的咪唑配体，可以提供Cu-A和血红素a之间的电子转移途径，两个可能的质子泵送途径，每个从基质到胞质表面，的结构，包括氢键，可能含有水分子的内部空腔，以及可以与氨基酸侧链的小可能构象变化形成氢键的结构。确定了化学质子产生H2O、去除生成水和O-2的可能通道。
The crystal structure of bovine heart cytochrome c oxidase at 2.8 Angstrom resolution with an R Value of 19.9 percent reveals 13 subunits, each different from the other, five phosphatidyl ethanolamines, three phosphatidyl glycerols and two cholates, two hemes A, and three copper, one magnesium, and one zinc. Of 3606 amino acid residues in the dimer, 3560 have been converged to a reasonable structure by refinement, A hydrogen-bonded system, including a propionate of a heme A (heme a), part of peptide backbone, and an imidazole ligand of Cu-A, could provide an electron transfer pathway between Cu-A and heme a, Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains. Possible channels for chemical protons to produce H2O, for removing the produced water, and for O-2, respectively, were identified.