The catalytic subunit of Escherichia coli nitrate reductase A contains a novel [4Fe-4S] cluster with a high-spin ground state.
The catalytic subunit of Escherichia coli nitrate reductase A contains a novel [4Fe-4S] cluster with a high-spin ground state.
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大肠杆菌硝酸还原酶 A 的催化亚基包含一个具有高自旋基态的新型 [4Fe-4S] 簇。
DOI：
10.1021/bi049938l
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发表时间：
2004
期刊：
影响因子：
2.9
通讯作者：
J. Weiner
中科院分区：
文献类型：
--
作者：
R. Rothery;M. Bertero;R. Cammack;M. Palak;F. Blasco;N. Strynadka;J. Weiner
我们利用EPR光谱、氧化还原电位法和蛋白质晶体学对大肠杆菌硝酸还原酶A （NarGHI）催化亚基（NarG）的[4Fe-4S]簇（FS0）进行了表征。FS0在NarGHI的晶体结构中清晰可见[Bertero， m.g., et . (2003) Nat. Struct。]但具有新的配位，包括一个His残基和三个Cys残基。在低温（<15 K）下，还原的NarGHI表现出以前未观察到的EPR信号，包括g = 5.023和g = 5.556的峰值。我们将这些特征分配给具有S =(3)/(2)基态的[4Fe-4S]（+）集群，g = 5.023和g = 5.556峰分别对应于表现delta =(1)/(2)和delta =(3)/(2)过渡的亚种群。这两个峰在pH 8.0时的中点电位约为-55 mV，在apomolybdo-NarGHI的EPR谱中被消除。apomolybdo-NarGHI的结构表明FS0仍然存在，但在残基的一个片段中存在明显的构象紊乱，其中包括一个Cys配体。在这些观察的基础上，我们将约化NarGHI的高自旋EPR特征归为FS0。
We have used EPR spectroscopy, redox potentiometry, and protein crystallography to characterize the [4Fe-4S] cluster (FS0) of the Escherichia coli nitrate reductase A (NarGHI) catalytic subunit (NarG). FS0 is clearly visible in the crystal structure of NarGHI [Bertero, M. G., et al. (2003) Nat. Struct. Biol. 10, 681-687] but has novel coordination comprising one His residue and three Cys residues. At low temperatures (<15 K), reduced NarGHI exhibits a previously unobserved EPR signal comprising peaks at g = 5.023 and g = 5.556. We have assigned these features to a [4Fe-4S](+) cluster with an S = (3)/(2) ground state, with the g = 5.023 and g = 5.556 peaks corresponding to subpopulations exhibiting DeltaS = (1)/(2) and DeltaS = (3)/(2) transitions, respectively. Both peaks exhibit midpoint potentials of approximately -55 mV at pH 8.0 and are eliminated in the EPR spectrum of apomolybdo-NarGHI. The structure of apomolybdo-NarGHI reveals that FS0 is still present but that there is significant conformational disorder in a segment of residues that includes one of the Cys ligands. On the basis of these observations, we have assigned the high-spin EPR features of reduced NarGHI to FS0.
大肠杆菌细胞色素 bo 羟基氧化酶中血红素-铜和血红素-血红素相互作用。
DOI：
--
发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Salerno,JC;Bolgiano,B;Poole,RK;Gennis,RB;Ingledew,WJ
通讯作者：
Ingledew,WJ
强烈火球菌铁氧还蛋白中新型铁硫簇的光谱表征。
DOI：
--
发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Conover,RC;Kowal,AT;Fu,WG;Park,JB;Aono,S;Adams,MW;Johnson,MK
通讯作者：
Johnson,MK