Protein-protein interaction regulates the direction of catalysis and electron transfer in a redox enzyme complex.
Protein-protein interaction regulates the direction of catalysis and electron transfer in a redox enzyme complex.
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DOI：
10.1021/ja405072z
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发表时间：
2013-07-17
影响因子：
15
通讯作者：
Jeuken LJ
中科院分区：
文献类型：
--
作者：
McMillan DG;Marritt SJ;Firer-Sherwood MA;Shi L;Richardson DJ;Evans SD;Elliott SJ;Butt JN;Jeuken LJ
众所周知，蛋白质之间的相互作用可以调节细胞信号和新陈代谢中的酶活性。在这里，我们证明了蛋白质-蛋白质相互作用通过改变催化的方向或偏向来调节呼吸链酶CymA的活性。CymA是广泛存在的NAPC/NIRT超家族中的一员，是一种MQ-7脱氢酶，它向圆圆希瓦氏菌多功能呼吸网络中的几个不同的末端还原酶提供电子。我们报道了Cyma在固体支撑的膜中的掺入，这种膜模仿了S.onedensis的内膜结构。石英晶体耗散微天平(QCM-D)解决了Cyma与其天然氧化还原配对之一富马酸黄色素c3(FCC3)还原酶之间形成稳定的络合物的问题。循环伏安法显示，Cyma单独作用只能还原MQ-7，而Cyma-Fcc3复合体催化了支持无氧呼吸所需的反应，即MQ-7的氧化。我们认为，MQ-7在Cyma中的氧化受限于对血红素的电子转移，而与Fcc3形成的络合物促进了沿着血红素氧化还原链的电子转移速率。这些结果揭示了一种尚未探索的机制，即细菌可以通过蛋白质-蛋白质相互作用来调节多分支的呼吸网络。
Protein–protein interactions are well-known to regulate enzyme activity in cell signaling and metabolism. Here, we show that protein–protein interactions regulate the activity of a respiratory-chain enzyme, CymA, by changing the direction or bias of catalysis. CymA, a member of the widespread NapC/NirT superfamily, is a menaquinol-7 (MQ-7) dehydrogenase that donates electrons to several distinct terminal reductases in the versatile respiratory network of Shewanella oneidensis. We report the incorporation of CymA within solid-supported membranes that mimic the inner membrane architecture of S. oneidensis. Quartz-crystal microbalance with dissipation (QCM-D) resolved the formation of a stable complex between CymA and one of its native redox partners, flavocytochrome c3 (Fcc3) fumarate reductase. Cyclic voltammetry revealed that CymA alone could only reduce MQ-7, while the CymA-Fcc3 complex catalyzed the reaction required to support anaerobic respiration, the oxidation of MQ-7. We propose that MQ-7 oxidation in CymA is limited by electron transfer to the hemes and that complex formation with Fcc3 facilitates the electron-transfer rate along the heme redox chain. These results reveal a yet unexplored mechanism by which bacteria can regulate multibranched respiratory networks through protein–protein interactions.
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Menaquinone-7 是四血红素醌醇脱氢酶 CymA 的特异性辅因子。
DOI：
10.1074/jbc.m112.348813
发表时间：
2012-04-20
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
McMillan DG;Marritt SJ;Butt JN;Jeuken LJ
通讯作者：
Jeuken LJ
影响因子：
3.9
作者：
Reimhult, E;Höök, F;Kasemo, B
通讯作者：
Kasemo, B
影响因子：
3.2
作者：
Myers, CR;Myers, JM
通讯作者：
Myers, JM
影响因子：
12.6
作者：
Biffinger, Justin C.;Pietron, Jeremy;Ringeisen, Bradley R.
通讯作者：
Ringeisen, Bradley R.
影响因子：
3.9
作者：
Marritt, Sophie J.;McMillan, Duncan G. G.;Butt, Julea N.
通讯作者：
Butt, Julea N.