通过二次通道调节RNA聚合酶
Bryce E Nickels1, Ann Hochschild
1Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Blg. D-1, Boston, MA 02115, USA.
Cell
|August 6, 2004
概括
RNA聚合酶利用二次通道使小分子进入活性部位. 这个通道对于通过与调节因子和小分子相互作用来调节酶活性至关重要.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 多子单元RNA聚合酶是基因转录的必要酶.
- 高分辨率的晶体结构揭示了关键的功能区域,包括二次通道.
- 假设二级通道是为了促进小分子的运输进入和离开酶的活性中心.
研究的目的:
- 阐明二次通道在RNA聚合酶功能中的作用.
- 了解调节因素和小分子如何与二次通道相互作用.
- 研究二次通道相互作用对转录特性的影响.
主要方法:
- 高分辨率的晶体学.
- 生物化学测定 生物化学测定
- 对RNA聚合酶复合物的结构分析.
主要成果:
- 水晶结构将二次通道确定为一个关键的接入点.
- 有证据表明,调节因素和小分子可以通过这种道进入活性部位.
- 二次通道的利用调节RNA聚合酶转录活动.
结论:
- 二级通道是RNA聚合酶的关键调节部位.
- 小分子和调节因素可以通过这个通道直接影响转录.
- 了解二级通道动态,可以了解转录控制机制.
相关概念视频
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Regulation of Expression at Multiple Steps
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...
Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...


