概括
细菌RNA在转录启动过程中获得尼古丁胺腺素二核酸 (NAD+) 或3′- 脱酸- 共酶A (dpCoA),而不是之后. 这种非正规启动核酸 (NCIN) 限制机制在体内发生,并影响RNA功能.
科学领域:
- 分子生物学
- 生物化学
- 遗传学
背景情况:
- RNA的5′端显著影响其稳定性,处理,局部化和翻译.
- 转录组调节包括在真核RNA中发现的5′帽子等修饰.
- 已观察到细菌RNA具有类似于真核细胞的5′端,例如尼古丁胺腺素二核酸 (NAD+) 或3′-脱酶A (dpCoA).
研究的目的:
- 阐明NAD+,NADH和dpCoA在细菌RNA中的结合机制.
- 要确定这些封顶是在转录后或转录启动期间添加的.
- 调查这种限制过程的结构基础和功能后果.
主要方法:
- 使用来自细菌和真核生物的RNA聚合酶 (RNAP II).
- 分析了促进体DNA序列在调节限制效率中的作用.
- 确定非正规启动核酸 (NCIN) 限制的体内发生和功能影响.
- 获得的转录启动复合物的晶体结构与NCIN覆盖的RNA.
主要成果:
- 证明NAD+,NADH和dpCoA在RNAP的新转录启动过程中被纳入非正规启动核酸 (NCIN).
- 表明细菌和真核RNAP II可以结合NCIN盖.
- 鉴定出促体DNA序列是NCIN限制效率的关键决定因素.
- 证实NCIN上限发生在体内并且具有功能性后果.
- 提供了晶体结构,揭示了NCIN封顶的机制和结构基础.
结论:
- 在转录启动过程中发生的ab initio过程,而不是转录后的修改.
- 这种机制涉及NAD+,NADH和dpCoA,在细菌和真核RNAP II中保存.
- 激发器序列决定了NCIN上限的效率.
- 以NCIN为媒介的初始上限可能是生活各个领域广泛的监管机制.
相关概念视频
02:36The Citric Acid Cycle
162.6K
The citric acid cycle, also known as the Krebs cycle or TCA cycle, consists of several energy-generating reactions that yield one ATP molecule, three NADH molecules, one FADH2 molecule, and two CO2 molecules.
162.6K
01:15Pyruvate Oxidation
169.2K
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
169.2K
01:045-Number Summary
5.7K
In a dataset, the 5-number summary includes the minimum data value, the data value of the first quartile, the median data value or data value of the second quartile, the data value of the third quartile, and the maximum data value. These 5 data values can be visualized as a box and whisker plot.
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
5.7K
01:29Role of Reduced Coenzymes NADH and FADH₂
16.9K
The energy released from the breakdown of the chemical bonds within nutrients can be stored either through the reduction of electron carriers or in the bonds of adenosine triphosphate (ATP). In living systems, a small class of compounds functions as mobile electron carriers, molecules that bind to and shuttle high-energy electrons between compounds in pathways. The principal electron carriers that will be considered originate from the B vitamin group and are derivatives of nucleotides; they are...
16.9K
02:18Alternative RNA Splicing
25.2K
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
25.2K
01:23RNA Interference
28.2K
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
28.2K