从PIWI域-siRNA指南复合体中对mRNA识别的结构洞察力
James S Parker1, S Mark Roe, David Barford
1Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK.
Nature
|April 1, 2005
概括
这项研究揭示了与指导RNA结合的阿尔戈诺特蛋白质的晶体结构,解释了它如何识别和准备目标信使RNA在RNA沉默通路中的分裂.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- RNA干扰 (RNAi) 和RNA沉默是基因调节的关键机制.
- 阿尔戈纳特蛋白质是这些过程的核心,利用指导RNA来准信使RNA (mRNA).
研究的目的:
- 阐明指导RNA结合的结构基础和阿尔戈诺特蛋白质对目标mRNA的识别.
- 在RNA沉默中提供对目标mRNA裂变机制的见解.
主要方法:
- 使用X射线晶体学来确定来自Archaeoglobus fulgidus的Piwi蛋白 (AfPiwi) 的结构.
- 结构被确定为复杂的小干扰RNA (siRNA) 类双重组,模仿指导RNA-向mRNA相互作用的关键特征.
主要成果:
- 晶体结构显示了一个保存的金属结合部位,定导向RNA的5'核酸.
- 该结构显示了第一个基对的解开,通过通道促进了目标mRNA的释放.
- PIWI域将导向-目标双重体容纳在A形螺旋中,将目标定位为分离.
结论:
- 该研究为阿尔戈纳特介导的目标mRNA识别提供了详细的结构机制.
- 这些发现揭示了阿尔戈纳特-siRNA复合物如何启动目标mRNA的分裂,进步了我们对RNA沉默的理解.
相关概念视频
RNA Interference
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...
Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
RNA Interference
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...
siRNA - Small Interfering RNAs
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
Experimental RNAi
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...


