クリオ・エム は 自然 の RNA 多値性 の 仕組み を 明らか に し ます
Liu Wang1,2, Jiahao Xie3, Tao Gong1
1The State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital; The State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center for Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
まとめ
生物学的RNA分子は複合的な構造に組み合わされ,二重体やより大きなナノ構造を形成します. 研究者らは冷凍電子顕微鏡を用いて これらのRNAアセンブリを動かす構造的モチーフとその潜在的機能を明らかにしました
科学分野:
- 生物化学
- 構造生物学
- 分子生物学
背景:
- 生物学的マクロモレキュルのホモオリゴメリゼーションは 細胞プロセスに不可欠な機能的アセンブリを形成する.
- 複合的な3D折り畳みを示唆するRNAファミリーの保存された二次構造にもかかわらず,RNA四次構造はめったに報告されません.
研究 の 目的:
- クリオ電子顕微鏡を用いて4つのRNAファミリーの3次元構造を決定する.
- RNAの多価性を駆動する構造的動機と分子間相互作用を解明する.
主な方法:
- RNAファミリーを特定するための比較ゲノム解析
- 高解像度構造 (2.6 - 4.6 アングストロム) を決定するための冷凍電子顕微鏡 (冷凍-EM).
主要な成果:
- ダイマーを形成するARRPOFとOLERNAファミリーの構造を決定した.
- ヘクサメリク,オクタメリク,ドゥデメリクナノ構造を形成するROOLとGOLDRNAファミリーの構造が解明された.
- 特定された構造的モチーフにはキスループ,パリンドロミックベースペアリング,Aスタッキング,金属イオン調整,擬似ノット,およびマイナー・グルーフの相互作用が含まれています.
結論:
- この研究は,RNAの多価性を駆動する分子間相互作用の分子基礎を提供する.
- これらの発見は,細胞プロセスにおけるRNAホモオリゴメリックアセンブリの潜在的機能的関連性についての洞察を提供します.
関連する概念動画
Cryo-electron Microscopy
3.2K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.2K
Ribozymes
11.0K
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can...
Ribozymes can...
11.0K
Leaky Scanning
5.0K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.0K
Nucleic Acid Structure
5.9K
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA...
DNA Structure
DNA...
5.9K
Bacterial RNA Polymerase
28.3K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
28.3K
Nucleic Acids
43.2K
Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning.
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes,...
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes,...
43.2K


