Enzymatic properties of purified Escherichia coli uvrABC proteins.
Enzymatic properties of purified Escherichia coli uvrABC proteins.
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纯化的大肠杆菌 uvrABC 蛋白的酶学特性。
DOI：
10.1073/pnas.80.20.6157
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发表时间：
1983
影响因子：
11.1
通讯作者：
Grossman,L
中科院分区：
文献类型：
--
作者：
Yeung,AT;Mattes,WB;Oh,EY;Grossman,L
将克隆的大肠杆菌K-12 uvrA和uvrB基因与质粒pKC30的PL启动子连锁扩增。uvrC基因在高拷贝数质粒prlm24中扩增。三种基因产物（每种情况下纯化纯度大于95%）和ATP是有效切割紫外线损伤dna所必需的。uvrABC蛋白与DNA中的受损位点紧密结合，在uvrB和uvrC蛋白有效结合之前，需要在ATP存在的情况下初始附着uvrA蛋白。利用克隆的lac - p-o区串联双插入作为uvrABC复合物的受损DNA底物，并分析每个嘧啶二聚体的5‘和3’切口，我们发现嘧啶二聚体的7个核苷酸5‘发生了一次断裂，而二聚体中同一对嘧啶的3-4个核苷酸3’发生了第二次断裂。在与二聚体互补的链中没有发现这样的断裂。DNA中切开片段的大小表明，在修复过程中，切口可能与切除反应相协调。
The cloned uvrA and uvrB genes of Escherichia coli K-12 were amplified by linkage to the PL promoter of plasmid pKC30. The uvrC gene was amplified in the high-copy-number plasmid pRLM 24. The three gene products (purified in each case to greater than 95% purity) and ATP are required to effectively incise UV-damaged DNAs. The uvrABC proteins bind tightly to damaged sites in DNA, requiring the initial attachment of the uvrA protein in the presence of ATP before productive binding of the uvrB and uvrC proteins. Using a cloned tandem double insert of the lac p-o region as a damaged DNA substrate for the uvrABC complex and analyzing the incision both 5' and 3' to each pyrimidine dimer, we found that one break occurs 7 nucleotides 5' to a pyrimidine dimer and a second break is made 3-4 nucleotides 3' from the same pair of pyrimidines in the dimer. No such breaks are found in the strand complementary to the dimer. The size of the incised fragment in the DNA suggests that incision may be coordinated with excision reactions in repair processes.