DNA切除修复与转录偶联

DNA Excision Repair and Coupling Transcription

细胞ＤＮＡ受到某些环境理化因子损伤后，其中活性转录基因和ＤＮＡ转录链上的损伤被优先切除修复，这种ＤＮＡ选择性修复直接与基因转录过程偶联．在大肠杆菌中已分离到实现此功能的转录修复偶联因子（ＴＲＣＦ），是由ｍｄｆ基因编码的一种具有ＡＴＰａｓｅ活性的ＤＮＡ结合蛋白．在真核细胞中，发现某些ＤＮＡ修复蛋白也在ＤＮＡ转录中起作用，如人ＤＮＡ切除修复基因ＥＲＣＧ－３编码产物，是转录因子ＴＦⅡＨ中最大亚基ｐ８９，酵母切除修复基因ＲＡＤ３就是编码因子ｂ的最大亚基ｐ８５．

With DNA lesions induced by environmental physical and chemical factors, actively transcribed genes and DNA transcribed strands were preferentially repaired.This preferential DNA repair directly connected with the process of gene transcription.A transcription-repair coupling factor (TRCF) encoded by mdf gene has been identified and isolated in E. coli. TRCF is a DNA binding protein with ATPase activity. In eukaryotes, some DNA repair proteins were found to be involved in transcription. For example, the largest subunit of general transcription factor TF ⅡH,p89,is the encoding product of human excision repair gene ERCC-3. And the excision repair gene RAD3 of yeast encodes the largest subunit of transcription factor b, p85.