Structural organization of the bovine adrenodoxin gene.
Structural organization of the bovine adrenodoxin gene.
复制标题
牛肾上腺素基因的结构组织。
DOI：
10.1093/oxfordjournals.jbchem.a123015
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发表时间：
1990
影响因子：
2.7
通讯作者：
T. Horiuchi
中科院分区：
文献类型：
--
作者：
Y. Sagara;H. Sawae;A. Kimura;Y. Sagara;K. Morohashi;K. Miyoshi;T. Horiuchi
测定了肾上腺皮质线粒体类固醇羟化系统的组成部分--牛肾上腺素(Ad)的基因结构。该基因看似是单拷贝，但除了真实的基因区外，还含有一个伪外显子。活性Ad的基因区被3个内含子分成4个外显子，大小至少为27kb。所有的剪接供体和受体都遵循GT/AG规则。通过引物延伸分析确定了转录起始点，推测5‘-侧翼区存在TATA盒和GC盒。在转录起始点上游存在一个12个碱基的序列CCAGGGCCAGGG。类固醇羟化细胞色素P-450基因的5‘侧翼区也有相似的序列：肾上腺皮质的P-450(SCC)、P-450(11β)、P-450(17α)和P-450(C21)。这五个序列的共同序列是CGCAGGGGCCATGGGA。伪外显子外显子1‘位于外显子1上游约0.5kb处，编码次要类型Ad mRNA的前肽，但在框架内有一个终止密码子(TAA)。在外显子1‘的5’侧翼区也存在TATA盒类似序列和CAAT盒类似序列。外显子1的GC含量在80%以上，而包括外显子1‘在内的其他4个外显子的GC含量都在40%左右。我们的观察结果表明，编码主要类型Ad mRNA的前肽区域的外显子1已经侵入了外显子1‘和外显子2之间的区域。
The gene structure of bovine adrenodoxin (Ad), a component of the steroid hydroxylating system in adrenal cortex mitochondria, was determined. This gene seems to be a single copy, but contains a pseudo exon in addition to the genuine gene region. The gene region for the active Ad is divided into 4 exons by 3 introns, and spans at least 27 kb. All the splice donor and acceptor sites follow the GT/AG rule. The transcription initiation site was determined by primer extension analysis, and putative TATA and GC boxes are present in the 5'-flanking region. A 12 base sequence, CCAGGGCCAGGG, is present 95 bases upstream from the transcription initiation site. A similar sequence was also found in the 5'-flanking regions of all genes for the steroid hydroxylating cytochromes P-450: P-450(SCC), P-450(11 beta), P-450(17 alpha), and P-450(C21), in the adrenal cortex. The consensus sequence for these five sequences is CGCAGGGCCATGGGA. The pseudo exon, exon 1', was present about 0.5 kb upstream from exon 1. It encodes the prepeptide region of the minor type Ad mRNA, but has a stop codon (TAA) in the frame. A TATA-box-like sequence and a CAAT-box-like sequence are also present in the 5'-flanking region of exon 1'. The GC content of exon 1 was over 80%, whereas for each of the other four exons, including exon 1', it was about 40%. Our observations suggest that exon 1, which encodes the prepeptide region of the major type Ad mRNA, has intruded into the region between exon 1' and exon 2.