The LYR protein subunit NB4M/NDUFA6 of mitochondrial complex I anchors an acyl carrier protein and is essential for catalytic activity
The LYR protein subunit NB4M/NDUFA6 of mitochondrial complex I anchors an acyl carrier protein and is essential for catalytic activity
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DOI：
10.1073/pnas.1322438111
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发表时间：
2014-04-08
影响因子：
11.1
通讯作者：
Zickermann, Volker
中科院分区：
文献类型：
--
作者：
Angerer, Heike;Radermacher, Michael;Zickermann, Volker
线粒体复合物I是氧化磷酸化系统中最大、最复杂的酶。它包括许多结构和功能基本未知的所谓辅助亚基。在这里，我们研究了NB4M亚基[NDUFA6，含LYR基序的蛋白6（LYRM 6）]，LYRM蛋白家族的成员。在酵母Yarrowia lipolytica中相应基因的染色体缺失导致线粒体酰基载体蛋白亚基ACPM 1从酶复合物和瘫痪的泛醌还原酶活性的伴随损失。交换LYR基序和相关的保守苯丙氨酸在亚基NB4M丙氨酸也废除了亚基ACPM 1的活性和结合。我们表明，通过单粒子电子显微镜和结构建模，亚基NB4M和ACPM1形成一个亚结构域，该亚结构域在已知参与控制复合物I的催化活性的中心亚结构域附近从外周臂突出。
Mitochondrial complex I is the largest and most complicated enzyme of the oxidative phosphorylation system. It comprises a number of so-called accessory subunits of largely unknown structure and function. Here we studied subunit NB4M [NDUFA6, LYR motif containing protein 6 (LYRM6)], a member of the LYRM family of proteins. Chromosomal deletion of the corresponding gene in the yeast Yarrowia lipolytica caused concomitant loss of the mitochondrial acyl carrier protein subunit ACPM1 from the enzyme complex and paralyzed ubiquinone reductase activity. Exchanging the LYR motif and an associated conserved phenylalanine by alanines in subunit NB4M also abolished the activity and binding of subunit ACPM1. We show, by single-particle electron microscopy and structural modeling, that subunits NB4M and ACPM1 form a subdomain that protrudes from the peripheral arm in the vicinity of central subunit domains known to be involved in controlling the catalytic activity of complex I.