EPR study of 1Asp-3Cys ligated 4Fe-4S iron-sulfur cluster in NB-protein (BchN-BchB) of a dark-operative protochlorophyllide reductase complex
EPR study of 1Asp-3Cys ligated 4Fe-4S iron-sulfur cluster in NB-protein (BchN-BchB) of a dark-operative protochlorophyllide reductase complex
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DOI：
10.1016/j.febslet.2010.11.044
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发表时间：
2011-01-03
期刊：
影响因子：
3.5
通讯作者：
Itoh, Shigeru
中科院分区：
文献类型：
--
作者：
Kondo, Toru;Nomata, Jiro;Itoh, Shigeru
暗作用原叶绿内酯氧化还原酶是一种类似于氮酶的酶，含有两个[4Fe-4S]簇，一个位于l蛋白((BchL)(2))，另一个位于nb蛋白(（BchN-BchB)(2)）。由1Asp/3Cys残基连接的nb -蛋白中还原的nb -团簇显示出较宽的S = 3/2电子顺磁共振信号，这在[4Fe-4S]团簇中是相当罕见的。突变的BchB-D36C蛋白中有一个4cys连接的nb -簇，其中Asp36被一个Cys取代，给出一个菱形正常S = 1/2信号，失去了催化活性。结果表明，Asp36有助于还原原叶绿内酯所需的低氧化还原电位。(C) 2010年欧洲生化学会联合会。Elsevier b.v.版权所有。
Dark-operative protochlorophyllide oxidoreductase, a nitrogenase-like enzyme, contains two [4Fe-4S] clusters, one in the L-protein ((BchL)(2)) and the other in the NB-protein ((BchN-BchB)(2)). The reduced NB-cluster in the NB-protein, which is ligated by 1Asp/3Cys residues, showed a broad S = 3/2 electron paramagnetic resonance signal that is rather rare in [4Fe-4S] clusters. A 4Cys-ligated NB-cluster in the mutated variant BchB-D36C protein, in which the Asp36 was replaced by a Cys, gave a rhombic normal S = 1/2 signal and lost the catalytic activity. The results suggest that Asp36 contributes to the low redox potential necessary to reduce protochlorophyllide. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.