一个组素八位体可以绕过一个转录聚合酶而不离开模板
V M Studitsky1, D J Clark, G Felsenfeld
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health Bethesda, Maryland 20892.
Cell
|January 28, 1994
概括
核细胞核在转录过程中沿着DNA移动,绕过转录聚合酶而不会解离. 这种转位机制确保了基因表达调节.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因法规 基因法规
背景情况:
- 核细胞是真核生物中DNA包装的基本单元.
- 了解转录期间的核细胞体动力学对于基因调节至关重要.
- 之前的模型提出了核细胞位移的各种机制.
研究的目的:
- 为了研究在体外转录过程中核细胞核移位和改造的机制.
- 阐明DNA模板长度和核酸度对核体运动的作用.
- 为核细胞组动态的特定转位模型提供证据.
主要方法:
- 在含有SP6RNA聚合酶促进体的定义DNA模板 (227bp和262bp) 上组装核细胞核.
- 在不同度的核糖核酸三酸盐 (rNTPs) 的体外转录试验.
- 在转录后对核细胞核相对于促进体的位置进行分析.
主要成果:
- 转录诱导了超过75-80bp的核细胞核转位,阻断了促进体.
- 核细胞转移发生在低rNTP度的分子内转移.
- 在较长的模板上核的位置取决于它的初始位置.
- 数据表明,在没有与DNA脱离的情况下进行了八位数转移.
结论:
- 强有力的证据支持DNA转位机制用于转录期间核细胞的重新定位.
- 核细胞的八分体"绕过"转录聚合酶.
- 这种机制允许转录,同时保持核细胞的完整性.
相关概念视频
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The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
02:35Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
01:53Bacterial Transcription
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Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
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02:35Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
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Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...