Structural and biochemical characterization of a quinol binding site of Escherichia coli nitrate reductase A
Structural and biochemical characterization of a quinol binding site of Escherichia coli nitrate reductase A
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DOI：
10.1074/jbc.m410457200
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发表时间：
2005-04-15
影响因子：
4.8
通讯作者：
Strynadka, NCJ
中科院分区：
文献类型：
--
作者：
Bertero, MG;Rothery, RA;Strynadka, NCJ
本文测定了大肠杆菌硝酸还原酶A(NarGHI)与五氯苯酚形成的络合物的晶体结构，其分辨率为2.0埃。我们已经证明，五氯苯酚是一种有效的喹酚：硝酸氧化还原酶活性的抑制剂，它也扰乱了位于膜锚定亚单位(NARI)中的一种血红素的EPR谱。这一新的结构信息与定点突变数据、生化分析和分子模拟一起，首次提供了NarGHI中苯二酚结合和氧化位点(Q-Site)的分子特征。还定义了与电子转移反应有关的可能的质子传导途径，提供了NarGHI在细菌膜上氧化泛喹酚的基本原子细节。
The crystal structure of Escherichia coli nitrate reductase A (NarGHI) in complex with pentachlorophenol has been determined to 2.0 angstrom of resolution. We have shown that pentachlorophenol is a potent inhibitor of quinol: nitrate oxidoreductase activity and that it also perturbs the EPR spectrum of one of the hemes located in the membrane anchoring subunit ( NarI). This new structural information together with site-directed mutagenesis data, biochemical analyses, and molecular modeling provide the first molecular characterization of a quinol binding and oxidation site (Q-site) in NarGHI. A possible proton conduction pathway linked to electron transfer reactions has also been defined, providing fundamental atomic details of ubiquinol oxidation by NarGHI at the bacterial membrane.