Human terminal deoxyribonucleotidyltransferase: molecular cloning and structural analysis of the gene and 5' flanking region.
Human terminal deoxyribonucleotidyltransferase: molecular cloning and structural analysis of the gene and 5' flanking region.
复制标题
人末端脱氧核糖核苷酸转移酶：基因和 5 侧翼区域的分子克隆和结构分析。
DOI：
10.1073/pnas.85.8.2489
复制
发表时间：
1988
影响因子：
11.1
通讯作者：
Coleman,MS
中科院分区：
文献类型：
--
作者：
Riley,LK;Morrow,JK;Danton,MJ;Coleman,MS
人末端脱氧核糖核苷酸转移酶（核苷三磷酸：DNA脱氧核苷酸转移酶，EC 2.7.7.31）cDNA包含1530个碱基对（bp）的开放阅读框，对应于含有510个氨基酸的蛋白质。编码的蛋白质是一种不依赖于模板的 DNA 聚合酶，仅在有限的正常和恶性前淋巴细胞群体中发现。为了开始研究负责末端脱氧核糖核苷酸转移酶组织特异性表达的遗传元件，分离并表征了含有整个人类基因的基因组克隆。最初，从人类淋巴母细胞系 MOLT-4R 生成的文库中分离出 cDNA 克隆。含有蛋白质整个编码区的 cDNA 克隆被用来从两个人类基因组文库中分离出一系列重叠的克隆。该基因包含 11 个外显子和 10 个内含子，跨度 49.4 KB。对包括外显子 1 的 5' 侧翼区域 (709 bp) 进行了测序。绘制了几个假定的转录起始位点。在翻译起始位点的500个核苷酸内，检测到一系列启动子元件。发现“TATA”和“CAAT”序列分别起始于核苷酸-185和-204、-328以及465和-505。在核苷酸-121处发现了环AMP依赖性启动子类似物的起始位点，在核苷酸-455处发现了对应于IgG启动子增强子(cd)的八碱基序列，以及在核苷酸-159处的IgG启动子(pd)类似物的起始位点。这些发现表明，编码末端脱氧核糖核苷酸转移酶的转录本的长度可能是可变的，并且转录可能受到多种遗传元件的影响。
Human terminal deoxyribonucleotidyltransferase (nucleoside-triphosphate:DNA deoxynucleotidylexotransferase, EC 2.7.7.31) cDNA contains an open reading frame of 1530 base pairs (bp) corresponding to a protein containing 510 amino acids. The encoded protein is a template-independent DNA polymerase found only in a restricted population of normal and malignant prelymphocytes. To begin to investigate the genetic elements responsible for the tissue-specific expression of terminal deoxyribonucleotidyltransferase, genomic clones containing the entire human gene were isolated and characterized. Initially, cDNA clones were isolated from a library generated from the human lymphoblastoid cell line, MOLT-4R. A cDNA clone containing the entire coding region of the protein was used to isolate a series of overlapping clones from two human genomic libraries. The gene comprises 11 exons and 10 introns and spans 49.4 kilobases. The 5' flanking region (709 bp) including exon 1 was sequenced. Several putative transcription initiation sites were mapped. Within 500 nucleotides of the translation start site, a series of promoter elements was detected. "TATA" and "CAAT" sequences, respectively, were found to start at nucleotides -185 and -204, -328, and 465 and -505. Start sites were found for a cyclic AMP-dependent promoter analog at nucleotide -121, an eight-base sequence corresponding to the IgG promoter enhancer (cd) at nucleotide -455, and an analog of the IgG promoter (pd) at nucleotide -159. These findings suggest that transcripts coding for terminal deoxyribonucleotidyltransferase may be variable in length and that transcription may be influenced by a variety of genetic elements.