Definition of the nuclear encoded protein composition of bovine heart mitochondrial complex I - Identification of two new subunits
Definition of the nuclear encoded protein composition of bovine heart mitochondrial complex I - Identification of two new subunits
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DOI：
10.1074/jbc.m209166200
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发表时间：
2002-12-27
影响因子：
4.8
通讯作者：
Hirst, J
中科院分区：
文献类型：
--
作者：
Carroll, J;Shannon, RJ;Hirst, J
牛心脏线粒体NADH：泛醌氧化还原酶（复合体1）是一个复杂的多亚基膜结合组装体。线粒体DNA编码了7个亚基，并描述了36个核编码亚基的序列。配合物I的亚基和两个亚基（α和β）分别在一维和二维凝胶上和反相高效液相色谱上进行了分离。质谱分析揭示了复合物I中两个以前未知的亚基，分别命名为B14.7和ESSS，每个亚基各有一个。在数据库中鉴定每个蛋白的编码序列，并通过cDNA克隆和测序进行确认。亚基B14.7有一个乙酰化的N端，无前序，包含四个潜在的跨膜螺旋。它与粗神经孢子虫复合体I中的21.3b亚基同源，与参与蛋白跨细胞膜易位的Tim17、Tim22、Tim23相关。ESSS亚基有一个断裂的线粒体输入序列和一个潜在的跨膜螺旋。共有45个不同的亚单位的牛复合体我现在已经被表征。
Mitochondrial NADH:ubiquinone oxidoreductase (complex 1) from bovine heart is a complicated multisubunit, membrane-bound assembly. Seven subunits are encoded by mitochondrial DNA, and the sequences of 36 nuclear encoded subunits have been described. The subunits of complex I and two subcomplexes (Ialpha and Ibeta) were resolved on one- and two-dimensional gels and by reverse-phase high performance liquid chromatography. Mass spectrometric analysis revealed two previously unknown subunits in complex I, named B14.7 and ESSS, one in each subcomplex. Coding sequences for each protein were identified in data bases and were confirmed by cDNA cloning and sequencing. Subunit B14.7 has an acetylated N terminus, no presequence, and contains four potential transmembrane helices. It is homologous to subunit 21.3b from complex I in Neurospora crassa and is related to Tim17, Tim22, and Tim23, which are involved in protein translocation across the inner membrane. Subunit ESSS has a cleaved mitochondrial import sequence and one potential transmembrane helix. A total of 45 different subunits of bovine complex I have now been characterized.