関連する実験動画
Updated: May 10, 2026

10:37
Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
Published on: May 10, 2018
RNA依存型RNAポリメリゼーションを開始するメカニズム
S J Butcher1, J M Grimes, E V Makeyev
1Institute of Biotechnology and Department of Biosciences, Viikki Biocenter, PO Box 56 (Viikinkaari 5), 00014 University of Helsinki, Finland.
Nature
|March 10, 2001
まとめ
研究者は,重要なウイルス酵素の構造を決定し,二重鎖RNAウイルスとフラビウイルスとの間の進化的リンクを明らかにしました. この発見は,ウイルスRNAの複製と転写の開始のための新しいモデルを提供します.
科学分野:
- ウイルス学 ウイルス学 ウイルス学
- 構造生物学 構造生物学とは
- 分子生物学は分子生物学である.
背景:
- ウイルスRNA依存型RNAポリメラーゼは,RNAウイルスの複製と転写に不可欠です.
- 二重鎖RNAウイルスは,これらのプロセスのためにカプシド内の酵素を利用し,単一鎖RNAと二重鎖RNAの両方を読み取ることができます.
- これまでのウイルスカプシドの構造の研究では,ポリメラーゼサブユニットの詳細な解像度が欠けていました.
研究 の 目的:
- 二重鎖RNA細菌の活性ポリメラーゼ亜単体の構造を解明する. phi6.6.
- 二重鎖RNAウイルスとフラビウイルス間の進化的関係を調査する.
- ウイルスのRNA複製と転写の開始のためのメカニズムを提案する.
主な方法:
- 2 Åの解像度のX線結晶学で,phi6ポリメラーゼ亜単体の構造を決定する.
- オリゴヌクレオチドとヌクレオシドトリフォスファート (NTP) の複合体を研究するための結晶浸漬と共結晶化技術.
主要な成果:
- phi6ポリメラーゼサブユニットのX線構造は,C型肝炎ウイルスのポリメラーゼと高い類似性を示し,進化的リンクを示唆しています.
- NTPを持つ複合体の構造は,二重鎖RNA処理と活性部位へのテンプレート供給のメカニズムを示唆する.
- テンプレートストランドのオーバーショット,特異性ポケット,および2つのNTPの関与を含むイニシアチブのモデルが提案されています.
結論:
- この研究は,二重鎖RNAウイルスポリメラーゼの高解像度構造を提供し,進化的つながりを明らかにしています.
- 構造データに基づいて,ウイルスのRNA複製と転写の開始のための詳細なメカニズムが提案されています.
- この研究は,基本的なウイルスRNA合成プロセスを理解するための作業モデルを提供します.
関連する概念動画
Bacterial RNA Polymerase
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...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Bacterial RNA Polymerase
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...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...

