GREA PROTEIN - A TRANSCRIPTION ELONGATION-FACTOR FROM ESCHERICHIA-COLI
GREA PROTEIN - A TRANSCRIPTION ELONGATION-FACTOR FROM ESCHERICHIA-COLI
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DOI：
10.1073/pnas.89.19.8899
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发表时间：
1992-10-01
影响因子：
11.1
通讯作者：
GOLDFARB, A
中科院分区：
文献类型：
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作者：
BORUKHOV, S;POLYAKOV, A;GOLDFARB, A
从大肠杆菌中分离出一种含有158个氨基酸的greA基因产物。当加入到停止的三元转录复合体中时，GreA蛋白诱导新生RNA的3'近端二核苷酸的切割和去除。切割产生的新的3'端可以延伸成更长的转录本。大苷介导的转录物裂解似乎允许三元复合体从由特定DNA位点诱导的无限期延长阻滞状态恢复转录。GreA蛋白在纯化过程中倾向于与RNA聚合酶相互作用，并在体外裂解过程中在RNA聚合酶分子之间循环。类似的生化活性在真核RNA聚合酶中也有报道，这表明转录物的切割和重新开始的延伸可能是一种普遍的转录机制。
A protein identified as the 158-amino acid product of the greA gene was isolated from Escherichia coli. When added to a halted ternary transcription complex, the GreA protein induced cleavage and removal of the 3' proximal dinucleotide from the nascent RNA. The new 3' terminus generated by the cleavage could be extended into longer transcripts. GreA-mediated cleavage of a transcript appears to permit a ternary complex to resume transcription from a state of indefinite elongation arrest induced by a specific DNA site. The GreA protein tended to interact with RNA polymerase during purification and recycled between RNA polymerase molecules in the course of the in vitro cleavage reaction. Similar biochemical activities have been reported in eukaryotic RNA polymerases, indicating that transcript cleavage and restart of elongation may be a general transcriptional mechanism.