Mitochondrial NADH:ubiquinone reductase: complementary DNA sequence of the import precursor of the bovine 75-kDa subunit.
Mitochondrial NADH:ubiquinone reductase: complementary DNA sequence of the import precursor of the bovine 75-kDa subunit.
复制标题
线粒体 NADH：泛醌还原酶：牛 75-kDa 亚基输入前体的互补 DNA 序列。
DOI：
10.1021/bi00450a031
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发表时间：
1989
期刊：
影响因子：
2.9
通讯作者：
John E. Walker
中科院分区：
文献类型：
--
作者：
M. Runswick;R. Gennis;I. Fearnley;John E. Walker
来自牛心脏线粒体的复合物I（NADH：泛醌氧化还原酶）的75-kDa亚基是其最大的亚基，并且是该酶的铁-硫（IP）片段的组分。它被编码在核DNA中，并被输入到细胞器中。蛋白质序列已确定在N-末端的完整蛋白质和部分切割产生的片段与溴化氰和金黄色葡萄球菌蛋白酶V8。这些数据的一部分已被用来设计两种混合物的寡核苷酸17个碱基长，含有192和256个不同的序列，已被合成和用作杂交探针，用于识别同源cDNA克隆。已经分离出两个不同但重叠的克隆，并且已经确定了克隆DNA的序列。它们共同编码复合物I的75-kDa亚基的前体。成熟蛋白的长度为704个氨基酸，计算分子量为75，961道尔顿，并且不包含可以折叠成足够长度的疏水性α螺旋以跨越膜的内膜的序列片段。它的前体具有23个氨基酸的N-末端延伸，以指定其从细胞质输入到核糖体中。17个半胱氨酸残基分散在整个75 kDa的亚基，其中一些是彼此接近的序列中的三个独立的组，并通过类比与其他铁硫蛋白，可以参与铁硫簇。（250字处删节）
The 75-kDa subunit of complex I (NADH:ubiquinone oxidoreductase) from bovine heart mitochondria is its largest subunit and is a component of the iron-sulfur (IP) fragment of the enzyme. It is encoded in nuclear DNA and is imported into the organelle. Protein sequences have been determined at the N-terminus of the intact protein and on fragments generated by partial cleavage with cyanogen bromide and with Staphylococcus aureus protease V8. Parts of these data have been used to design two mixtures of oligonucleotides 17 bases long, containing 192 and 256 different sequences, which have been synthesized and used as hybridization probes for identification of cognate cDNA clones. Two different but overlapping clones have been isolated, and the sequences of the cloned DNAs have been determined. Together they code for a precursor of the 75-kDa subunit of complex I. The mature protein is 704 amino acids in length, has a calculated molecular mass of 75,961 daltons, and contains no segments of sequence that could be folded into hydrophobic alpha-helixes of sufficient length to span the inner membrane of the mitochondrion. Its precursor has an N-terminal extension of 23 amino acids to specify its import into the mitochondrion from the cytoplasm. Seventeen cysteine residues are dispersed throughout the 75-kDa subunit; some of them are close to each other in the sequence in three separate groups and, by analogy with other iron-sulfur proteins, could be involved in iron-sulfur clusters.(ABSTRACT TRUNCATED AT 250 WORDS)