A conserved arginine residue is critical for stabilizing the N2 FeS cluster in mitochondrial complex I.
A conserved arginine residue is critical for stabilizing the N2 FeS cluster in mitochondrial complex I.
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DOI：
10.1016/j.jbc.2021.100474
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发表时间：
2021-01
期刊：
影响因子：
--
通讯作者：
Hirst J
中科院分区：
文献类型：
--
作者：
Hameedi MA;Grba DN;Richardson KH;Jones AJY;Song W;Roessler MM;Wright JJ;Hirst J
呼吸复合物I（NADH：泛醌氧化还原酶）是电子传递链的第一个酶，捕获由NADH氧化和泛醌还原释放的自由能，以使质子穿过能量转导膜并在氧化磷酸化期间驱动ATP合成。将电子直接转移到泛醌的辅因子是位于NDUFS 2/NUCM亚基中的铁硫簇（N2）。附近的精氨酸残基（R121），它形成的N2簇的第二个配位球的一部分，是已知的posterionally二甲基化，但其功能和结构的意义是未知的。在这里，我们表明，这种精氨酸残基（R121 M/K）的突变废除醌还原酶活性，伴随着从电子顺磁共振（EPR）谱的N2签名的消失。NDUFS 2-R121 M复合物I在3.7 μ m分辨率下的冷冻-EM结构分析鉴定出在其他完整酶内不存在立方烷N2簇是功能障碍的原因。该突变进一步诱导了醌结合位点附近元素的局部紊乱，这与簇和底物结合区域之间的密切联系一致。我们的研究结果表明，R121是必要的N2簇的形成和/或稳定性，并强调了结构分析的重要性，复杂的I变体的生化和光谱数据的机制解释。
Respiratory complex I (NADH:ubiquinone oxidoreductase), the first enzyme of the electron-transport chain, captures the free energy released by NADH oxidation and ubiquinone reduction to translocate protons across an energy-transducing membrane and drive ATP synthesis during oxidative phosphorylation. The cofactor that transfers the electrons directly to ubiquinone is an iron–sulfur cluster (N2) located in the NDUFS2/NUCM subunit. A nearby arginine residue (R121), which forms part of the second coordination sphere of the N2 cluster, is known to be posttranslationally dimethylated but its functional and structural significance are not known. Here, we show that mutations of this arginine residue (R121M/K) abolish the quinone-reductase activity, concomitant with disappearance of the N2 signature from the electron paramagnetic resonance (EPR) spectrum. Analysis of the cryo-EM structure of NDUFS2-R121M complex I at 3.7 Å resolution identified the absence of the cubane N2 cluster as the cause of the dysfunction, within an otherwise intact enzyme. The mutation further induced localized disorder in nearby elements of the quinone-binding site, consistent with the close connections between the cluster and substrate-binding regions. Our results demonstrate that R121 is required for the formation and/or stability of the N2 cluster and highlight the importance of structural analyses for mechanistic interpretation of biochemical and spectroscopic data on complex I variants.
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DOI：
10.1107/s2059798318009324
发表时间：
2018-09-01
期刊：
Acta crystallographica. Section D, Structural biology
影响因子：
--
作者：
Afonine PV;Klaholz BP;Moriarty NW;Poon BK;Sobolev OV;Terwilliger TC;Adams PD;Urzhumtsev A
通讯作者：
Urzhumtsev A
影响因子：
4.3
作者：
Djafarzadeh, R;Kerscher, S;Brandt, U
通讯作者：
Brandt, U
影响因子：
4.3
作者：
D'Imprima, Edoardo;Mills, Deryck J.;Vonck, Janet
通讯作者：
Vonck, Janet
影响因子：
3
作者：
de la Rosa-Trevin, J. M.;Quintana, A.;Carazo, J. M.
通讯作者：
Carazo, J. M.
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH