Molecular cloning of a cDNA encoding rat NADH-cytochrome b5 reductase and the corresponding gene.
Molecular cloning of a cDNA encoding rat NADH-cytochrome b5 reductase and the corresponding gene.
复制标题
编码大鼠 NADH-细胞色素 b5 还原酶和相应基因的 cDNA 的分子克隆。
DOI：
10.1093/oxfordjournals.jbchem.a123130
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Y. Sakaki
中科院分区：
文献类型：
--
作者：
S. Zenno;M. Hattori;Y. Misumi;T. Yubisui;Y. Sakaki
使用人 b5R cDNA 作为探针，从大鼠肝脏 cDNA 文库中分离编码 NADH-细胞色素 b5 还原酶 (b5R) 的大鼠 cDNA。该cDNA长1,905个核苷酸，由38个核苷酸长的5'端非翻译区、编码301个氨基酸残基的903个核苷酸长的开放阅读框区、952个核苷酸长的3'端非翻译区和poly(A)尾组成。从cDNA序列推导的氨基酸序列表明，与该酶的成熟形式相比，大鼠b5R前体仅在N末端含有一个额外的氨基酸（Met）残基，这表明该酶易位至微粒体膜不需要额外的前导肽。从大鼠基因组DNA文库中分离出编码b5R基因的基因组DNA。该基因长约17 kb，由9个外显子和8个内含子组成。该酶的膜结合域和催化域之间的连接位于外显子 2 的中间，这表明该酶的两种形式，即膜结合型和可溶性形式，可能是通过翻译后加工产生的。该基因可能的启动子区域不包含 TATA 盒，而是包含四个 GC 盒序列（GGGCGG 和 CCGCCC），代表转录因子 SP1 的潜在结合位点。 b5R基因似乎具有看家基因的结构特征。
Rat cDNA encoding NADH-cytochrome b5 reductase (b5R) was isolated from a rat liver cDNA library using a human b5R cDNA as a probe. The cDNA was 1,905 nucleotides long, consisting of a 5'-terminal untranslated region of 38 nucleotides long, an open reading frame region of 903 nucleotides long encoding 301 amino acid residues, a 3'-terminal untranslated region of 952 nucleotide long, and a poly(A) tail. The amino acid sequence deduced from the cDNA sequence indicated that the rat b5R precursor contained only one extra amino acid (Met) residue at the N terminus, in comparison with the mature form of the enzyme, suggesting that no extra leader peptide is required for translocation of the enzyme to the microsome membrane. Genomic DNA encoding the b5R gene was isolated from rat genomic DNA libraries. The gene was about 17 kb long, and consisted of nine exons and eight introns. The junction between the membrane-binding and catalytic domains of the enzyme was found in the middle of exon 2, suggesting the possibility that the two forms of the enzyme, namely the membrane-bound and soluble forms, are generated through post-translational processing. The possible promoter region of the gene contained no TATA box but four GC box sequences (GGGCGG and CCGCCC), representing potential binding sites for the transcription factor, SP1. The b5R gene seems to have structural characteristics of a house-keeping gene.