Mycobacterial RNA polymerase forms unstable open promoter complexes that are stabilized by CarD.
Mycobacterial RNA polymerase forms unstable open promoter complexes that are stabilized by CarD.
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DOI：
10.1093/nar/gku1231
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发表时间：
2015-01
影响因子：
14.9
通讯作者：
Campbell EA
中科院分区：
文献类型：
--
作者：
Davis E;Chen J;Leon K;Darst SA;Campbell EA
大肠杆菌是细菌RNA聚合酶（RNAP）的典型生物，RNAP的生物化学特性主要集中在大肠杆菌上。coli RNAP已被公认为所有细菌RNAP的一般代表。在这里，我们直接比较了分枝杆菌转录系统与大肠杆菌转录系统的起始特性。coliRNAP启动子。详细的表征包括失败的转录测定，RNAP/启动子复合物的稳定性测定和DNA酶I和KMnO 4足迹。基于足迹法，我们发现E.大肠杆菌和分枝杆菌RNAP使用非常相似的蛋白质/DNA相互作用，并产生相同的转录泡。然而，我们发现由E. coli RNAP在两个启动子上形成的开放启动子复合物是高度稳定的并且基本上是不可逆的（寿命远大于1小时），而由分枝杆菌RNAP在相同的两个启动子上形成的开放启动子复合物是非常不稳定的（寿命约为2分钟或更短）并且容易可逆。我们在这里表明，CardD，一种必需的分枝杆菌转录激活因子，在E。大肠杆菌，通过防止转录泡破裂来显着稳定分枝杆菌RNAP/开放启动子复合物。
Escherichia coli has served as the archetypal organism on which the overwhelming majority of biochemical characterizations of bacterial RNA polymerase (RNAP) have been focused; the properties of E. coli RNAP have been accepted as generally representative for all bacterial RNAPs. Here, we directly compare the initiation properties of a mycobacterial transcription system with E. coli RNAP on two different promoters. The detailed characterizations include abortive transcription assays, RNAP/promoter complex stability assays and DNAse I and KMnO4 footprinting. Based on footprinting, we find that promoter complexes formed by E. coli and mycobacterial RNAPs use very similar protein/DNA interactions and generate the same transcription bubbles. However, we find that the open promoter complexes formed by E. coli RNAP on the two promoters tested are highly stable and essentially irreversible (with lifetimes much greater than 1 h), while the open promoter complexes on the same two promoters formed by mycobacterial RNAP are very unstable (lifetimes of about 2 min or less) and readily reversible. We show here that CarD, an essential mycobacterial transcription activator that is not found in E. coli, stabilizes the mycobacterial RNAP/open promoter complexes considerably by preventing transcription bubble collapse.
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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：
6.4
作者：
Czyz A;Mooney RA;Iaconi A;Landick R
通讯作者：
Landick R
影响因子：
64.8
作者：
BURGESS, RR;TRAVERS, AA;BAUTZ, EKF
通讯作者：
BAUTZ, EKF
影响因子：
5.6
作者：
CARPOUSIS, AJ;GRALLA, JD
通讯作者：
GRALLA, JD