转录因子sigma-54对促进体DNA的特定结合
Nature
|July 30, 1992
概括
单独的Sigma-54 (sigma 54) 结合了促进体DNA,促进了用于转录启动的闭合复合组合. 需要激活蛋白才能过渡到开放复合体,突出西格玛54,突出西格玛54.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 转录启动涉及在RNA合成开始地点附近的DNA上组装特定的蛋白质复合体.
- 通过某些增强剂结合蛋白激活转录,需要含有sigma-54 (sigma 54) 转录因子的RNA聚合酶全酶.
研究的目的:
- 在转录启动的背景下,研究sigma-54 (sigma 54) 的特定DNA结合特性.
- 阐明sigma-54 (sigma 54) 在促进体复合物的形成中的作用及其与RNA聚合酶的相互作用.
主要方法:
- 用DNA结合测试来评估sigma-54 (sigma 54) 与促进体DNA的相互作用.
- 足迹检测技术用于确定DNA结合RNA聚合酶全酶上sigma-54 (sigma 54) 的位置.
主要成果:
- 单 Sigma-54 (sigma 54) 单独特别结合促进体 DNA,对全酶-DNA 接触有显著的贡献.
- 与DNA结合的西格玛-54 (sigma 54) 不会诱导链分离,但有助于形成一个封闭的促进体复合体.
- 西格玛-54 (sigma 54) 位于与DNA结合的全酶的前沿.
结论:
- 西格玛-54 (sigma 54) 在特定促进体识别和转录复合体组装的初始步骤中起着至关重要的作用.
- 西格玛-54 (sigma 54) 的DNA结合活性对于形成一个封闭的促进体复合物至关重要,这需要随后激活以进行DNA化.
- 涉及sigma-54 (sigma 54) 的转录启动机制与真核RNA聚合酶II系统有相似之处.
相关概念视频
02:08Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
01:53Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
01:26DNA Bacteriophages
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...