NusA protein is necessary and sufficient in vitro for phage lambda N gene product to suppress a rho-independent terminator placed downstream of nutL.
NusA protein is necessary and sufficient in vitro for phage lambda N gene product to suppress a rho-independent terminator placed downstream of nutL.
复制标题
NusA 蛋白在体外对于噬菌体 lambda N 基因产物抑制位于 nutL 下游的 rho 独立终止子是必要且充分的。
DOI：
10.1073/pnas.85.8.2494
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发表时间：
1988
影响因子：
11.1
通讯作者：
Das,A
中科院分区：
文献类型：
--
作者：
Whalen,W;Ghosh,B;Das,A
噬菌体λ N蛋白的转录抗终止作用仅用纯化的组分在体外复制。我们已经放置了一个强大的rho-独立的终止子，λ tR '，在PL操纵子约200个碱基对下游的N-识别位点，nutL，并监测终止和径流转录单轮转录线性质粒产生。在NusA存在下（NusA是与抗终止有关的几种宿主因子之一），发现N实际上消除了tR '处的终止。如果终止子前面有一个有缺陷的坚果位点，N不能抑制终止。因此，在通过nut位点的转录过程中，N和NusA可以在不存在任何其他辅助因子的情况下将RNA聚合酶修饰为终止抗性形式。
Transcription antitermination by phage lambda N protein is reproduced in vitro solely with purified components. We have placed a strong rho-independent terminator, lambda tR', in the PL operon about 200 base pairs downstream from the N-recognition site, nutL, and have monitored terminated and run-off transcripts produced by single-round transcription of linear plasmids. In the presence of NusA, one of several host factors implicated in antitermination, N is found to virtually abolish termination at tR'. N is unable to suppress termination if the terminator is preceded by a defective nut site. Thus, during transcription through the nut site, N and NusA can modify RNA polymerase to a termination-resistant form in the absence of any other accessory factor.