Distinct functions of the RNA polymerase σ subunit region 3.2 in RNA priming and promoter escape.
Distinct functions of the RNA polymerase σ subunit region 3.2 in RNA priming and promoter escape.
复制标题
RNA聚合酶σ亚基区3.2在RNA启动和启动子逃脱中的不同功能。
DOI：
10.1093/nar/gkt1384
复制
发表时间：
2014-04
影响因子：
14.9
通讯作者：
Kulbachinskiy A
中科院分区：
文献类型：
--
作者：
Pupov D;Kuzin I;Bass I;Kulbachinskiy A
细菌核糖核酸聚合酶的σ亚基参与了转录启动的所有步骤，包括启动子识别和开放、启动合成、流产启动和启动子逃逸。启动子识别后的σ功能被认为依赖于其保守区RNAP3.2，该保守区直接接触启动子σ活性中心上游并占据RNAExit路径。本工作中对大肠杆菌σ70亚基该区域替换和缺失的转录影响的分析表明：(I)RNAP3.2手指上的单个残基共同参与了σ的启动，可能是通过将模板DNA链定位在活性中心，但对启动子逃逸并不是关键的；(Ii)σ3.2在σ出口通道中的物理存在对于启动子逃逸是重要的；(Iii)RNA3.2促进σ在起始过程中解离并抑制σ依赖的启动子-近端停顿；(Iv)σ3.2有助于变构抑制利福霉素启动的NTP结合。因此，σ区在转录的启动和抗生素的抑制中发挥着不同的功能。真核细胞因子TFIIB的B-阅读器元件可能在RNAPII转录中发挥类似的作用，揭示了生命各个领域转录启动的共同原理。
The σ subunit of bacterial RNA polymerase (RNAP) has been implicated in all steps of transcription initiation, including promoter recognition and opening, priming of RNA synthesis, abortive initiation and promoter escape. The post-promoter-recognition σ functions were proposed to depend on its conserved region σ3.2 that directly contacts promoter DNA immediately upstream of the RNAP active centre and occupies the RNA exit path. Analysis of the transcription effects of substitutions and deletions in this region in Escherichia coli σ70 subunit, performed in this work, suggests that (i) individual residues in the σ3.2 finger collectively contribute to RNA priming by RNAP, likely by the positioning of the template DNA strand in the active centre, but are not critical to promoter escape; (ii) the physical presence of σ3.2 in the RNA exit channel is important for promoter escape; (iii) σ3.2 promotes σ dissociation during initiation and suppresses σ-dependent promoter-proximal pausing; (iv) σ3.2 contributes to allosteric inhibition of the initiating NTP binding by rifamycins. Thus, region σ3.2 performs distinct functions in transcription initiation and its inhibition by antibiotics. The B-reader element of eukaryotic factor TFIIB likely plays similar roles in RNAPII transcription, revealing common principles in transcription initiation in various domains of life.
登录
查看更多内容
影响因子：
64.5
作者：
Feklistov A;Darst SA
通讯作者：
Darst SA
影响因子：
16
作者：
Feklistov, Andrey;Barinova, Nataliya;Kulbachinskiy, Andrey
通讯作者：
Kulbachinskiy, Andrey
影响因子：
14.9
作者：
GOURSE, RL
通讯作者：
GOURSE, RL
影响因子：
16
作者：
Campbell, EA;Tupy, JL;Darst, SA
通讯作者：
Darst, SA
影响因子：
16.8
作者：
Brodolin, K;Zenkin, N;Heumann, H
通讯作者：
Heumann, H