...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Molecular cloning of the human XRCC1 gene, which corrects defective DNA strand break repair and sister chromatid exchange.
【24h】

Molecular cloning of the human XRCC1 gene, which corrects defective DNA strand break repair and sister chromatid exchange.

机译：人类XRCC1基因的分子克隆，可纠正有缺陷的DNA链断裂修复和姐妹染色单体交换。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We describe the cloning and function of the human XRCC1 gene, which is the first mammalian gene isolated that affects cellular sensitivity to ionizing radiation. The CHO mutant EM9 has 10-fold-higher sensitivity to ethyl methanesulfonate, 1.8-fold-higher sensitivity to ionizing radiation, a reduced capacity to rejoin single-strand DNA breaks, and a 10-fold-elevated level of sister chromatid exchange compared with the CHO parental cells. The complementing human gene was cloned from a cosmid library of a tertiary transformant. Two cosmid clones produced transformants that showed approximately 100% correction of the repair defect in EM9 cells, as determined by the kinetics of strand break repair, cell survival, and the level of sister chromatid exchange. A nearly full-length clone obtained from the pcD2 human cDNA expression library gave approximately 80% correction of EM9, as determined by the level of sister chromatid exchange. Based on an analysis of the nucleotide sequence of the cDNA insert compared with that of the 5' end of the gene from a cosmid clone, the cDNA clone appeared to be missing approximately 100 bp of transcribed sequence, including 26 nucleotides of coding sequence. The cDNA probe detected a single transcript of approximately 2.2 kb in HeLa polyadenylated RNA by Northern (RNA) blot hybridization. From the open reading frame and the positions of likely start sites for transcription and translation, the size of the putative XRCC1 protein is 633 amino acids (69.5 kDa). The size of the XRCC1 gene is 33 kb, as determined by localizing the endpoints on a restriction endonuclease site map of one cosmid clone. The deduced amino acid sequence did not show significant homology with any protein in the protein sequence data bases examined.
机译：我们描述了人类XRCC1基因的克隆和功能，这是第一个分离的影响细胞对电离辐射敏感性的哺乳动物基因。 CHO突变体EM9对甲磺酸乙酯的敏感性高10倍，对电离辐射的敏感性高1.8倍，重新结合单链DNA断裂的能力降低，与姊妹染色单体交换相比，其水平提高了10倍CHO亲代细胞。从第三转化体的粘粒文库中克隆出互补的人类基因。两个粘粒克隆产生的转化体显示出EM9细胞中修复缺陷的大约100％的校正，这是通过链断裂修复的动力学，细胞存活以及染色单体交换水平确定的。由pcD2人cDNA表达文库获得的近乎全长的克隆，通过姐妹染色单体交换的水平确定，对EM9的校正约为80％。基于与粘粒克隆的基因的5'末端的cDNA插入物的核苷酸序列比较的分析，发现cDNA克隆似乎缺少转录的序列约100bp，包括编码序列的26个核苷酸。 cDNA探针通过Northern（RNA）印迹杂交检测到HeLa聚腺苷酸化RNA中约2.2 kb的单个转录本。从开放阅读框和可能的转录和翻译起始位点的位置来看，推定的XRCC1蛋白的大小为633个氨基酸（69.5 kDa）。 XRCC1基因的大小为33 kb，这是通过将一个粘粒克隆的限制性内切核酸酶位点图上的端点定位来确定的。推导的氨基酸序列与所检查的蛋白质序列数据库中的任何蛋白质均未显示出显着同源性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号