Preferential interaction of the his pause RNA hairpin with RNA polymerase beta subunit residues 904-950 correlates with strong transcriptional pausing.
Preferential interaction of the his pause RNA hairpin with RNA polymerase beta subunit residues 904-950 correlates with strong transcriptional pausing.
复制标题
His 暂停 RNA 发夹与 RNA 聚合酶 β 亚基残基 904-950 的优先相互作用与强转录暂停相关。
DOI：
10.1073/pnas.94.16.8433
复制
发表时间：
1997
影响因子：
11.1
通讯作者：
Landick,R
中科院分区：
文献类型：
--
作者：
Wang,D;Severinov,K;Landick,R
RNA二级结构（发夹）是由RNA聚合酶产生的新生RNA形成的，是许多调节转录的信号的重要组成部分，包括一些暂停位点，所有ρ-非依赖性终止子和一些反终止子。在其前导序列的停顿位点，一个5 bp-茎，8 nt-环的停顿RNA发夹从RNA 3′端形成11 nt，并稳定了一个转录复合物构象，该构象缓慢地与NTP底物反应。这种稳定似乎至少部分取决于与RNA聚合酶的相互作用。我们通过交联特异性定位在发夹环中的5-iodoUMP来测试RNA发夹与暂停的聚合酶的相互作用。在停顿构象中，停顿发夹与β904-950的强烈和不寻常的交联取代了与β′和β的其他部分的交联，这些交联发生在发夹形成之前的非停顿复合物中。新生RNA相互作用的这些变化可能抑制RNA 3′端在暂停复合物中的反应性排列，并与ρ-非依赖性终止子处的事件有关。
RNA secondary structures (hairpins) that form as the nascent RNA emerges from RNA polymerase are important components of many signals that regulate transcription, including some pause sites, all ρ-independent terminators, and some antiterminators. At thehisleader pause site, a 5-bp-stem, 8-nt-loop pause RNA hairpin forms 11 nt from the RNA 3′ end and stabilizes a transcription complex conformation slow to react with NTP substrate. This stabilization appears to depend at least in part on an interaction with RNA polymerase. We tested for RNA hairpin interaction with the paused polymerase by crosslinking 5-iodoUMP positioned specifically in the hairpin loop. In the paused conformation, strong and unusual crosslinking of the pause hairpin to β904–950 replaced crosslinking to β′ and to other parts of β that occurred in nonpaused complexes prior to hairpin formation. These changes in nascent RNA interactions may inhibit reactive alignment of the RNA 3′ end in the paused complex and be related to events at ρ-independent terminators.