INTRINSIC TRANSCRIPT CLEAVAGE ACTIVITY OF RNA-POLYMERASE
INTRINSIC TRANSCRIPT CLEAVAGE ACTIVITY OF RNA-POLYMERASE
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DOI：
10.1073/pnas.92.10.4596
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发表时间：
1995-05-09
影响因子：
11.1
通讯作者：
BORUKHOV, S
中科院分区：
文献类型：
--
作者：
ORLOVA, M;NEWLANDS, J;BORUKHOV, S
大肠杆菌的GreA和GreB转录物切割因子抑制延伸停滞，并可能在转录中起校对作用。把它关掉。coligreA（-）greB（-）突变体的RNA聚合酶具有很强的转录本切割活性。弱碱性pH通过诱导三元复合物中的转录物切割和通过切割和重启反应拮抗延伸停滞来模拟Gre蛋白的作用。因此，转录物切割与RNA的聚合/焦磷酸解一起沿着构成RNA聚合酶的第二酶学活性，而Gre蛋白仅增强该内在性质。
The GreA and GreB transcript cleavage factors of Escherichia coli suppress elongation arrest and may have a proofreading role in transcription. With the use off. coli greA(-)greB(-) mutant, RNA polymerase is demonstrated to possess substantial intrinsic transcript cleavage activity. Mildly alkaline pH mimics the effect of the Gre proteins by inducing transcript cleavage in ternary complexes and antagonizing elongation arrest through a cleavage-and-restart reaction. Thus, transcript cleavage constitutes the second enzymological activity of RNA polymerase along with polymerization/pyrophosphorolysis of RNA, whereas the Gre proteins merely enhance this intrinsic property.