Impact of residues remote from the catalytic centre on enzyme catalysis of copper nitrite reductase.
Impact of residues remote from the catalytic centre on enzyme catalysis of copper nitrite reductase.
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DOI：
10.1038/ncomms5395
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发表时间：
2014-07-15
影响因子：
16.6
通讯作者：
Hasnain, S. Samar
中科院分区：
文献类型：
--
作者：
Leferink, Nicole G. H.;Antonyuk, Svetlana V.;Houwman, Joseline A.;Scrutton, Nigel S.;Eady, Robert R.;Hasnain, S. Samar
酶机制通常通过结构信息点突变来探测，并测量它们对酶性质的影响，以测试机制假设。在许多情况下，挑战在于报告复杂且通常相互关联的催化要素。突变对酶机制产生长期影响的证据仍然很少，这限制了合成催化剂以可预测的方式设计/重新设计。在这里，我们表明，通过对距离 2 型 Cu (T2Cu) 催化位点 12 Å 的表面暴露的苯丙氨酸残基 (Phe306) 进行突变，提高亚硝酸铜还原酶活性位点口袋的可及性，深刻影响分子内电子转移、底物结合和催化活性。结构和动力学研究提供了对底物的较低亲和力以及反应中限速步骤的改变的解释。我们的结果表明，远离活性位点的残基可以通过相对较小的结构扰动驱动机械变化，从而对酶催化产生显着影响。 酶催化位点内的残基对于活性很重要，但更远的残基是否也对突变敏感尚不清楚。在这里，Leferink 等人。结果表明，硝酸铜还原酶中距离活性位点 12Å 的残基突变会扰乱酶的功能。
Enzyme mechanisms are often probed by structure-informed point mutations and measurement of their effects on enzymatic properties to test mechanistic hypotheses. In many cases, the challenge is to report on complex, often inter-linked elements of catalysis. Evidence for long-range effects on enzyme mechanism resulting from mutations remains sparse, limiting the design/redesign of synthetic catalysts in a predictable way. Here we show that improving the accessibility of the active site pocket of copper nitrite reductase by mutation of a surface-exposed phenylalanine residue (Phe306), located 12 Å away from the catalytic site type-2 Cu (T2Cu), profoundly affects intra-molecular electron transfer, substrate-binding and catalytic activity. Structures and kinetic studies provide an explanation for the lower affinity for the substrate and the alteration of the rate-limiting step in the reaction. Our results demonstrate that distant residues remote from the active site can have marked effects on enzyme catalysis, by driving mechanistic change through relatively minor structural perturbations. Residues within the catalytic site of enzymes are important for activity, but whether more distant residues are also sensitive to mutation is unclear. Here, Leferink et al. show that mutation of residues in copper nitrate reductase that are 12Å away from the active site perturb enzyme function.
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DOI：
10.1107/s0907444905036693
发表时间：
2006-01-01
影响因子：
2.2
作者：
Evans, P
通讯作者：
Evans, P
DOI：
10.1126/science.1204824
发表时间：
2011-08-12
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Kaan HY;Hackney DD;Kozielski F
通讯作者：
Kozielski F
影响因子：
5.6
作者：
Ellis, MJ;Dodd, FE;Hasnain, SS
通讯作者：
Hasnain, SS
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
DOI：
10.1073/pnas.0504207102
发表时间：
2005-08-23
影响因子：
11.1
作者：
Antonyuk, SV;Strange, RW;Hasnain, SS
通讯作者：
Hasnain, SS