グローバルRNA結合タンパク質KhpBによるRNA認識におけるKH-R3H領域の協力
Kenji Fukui1, Takeshi Murakawa2, Seiki Baba3
1Department of Biochemistry, Faculty of Medicine, Osaka Medical and Pharmaceutical University, 2-7 Daigaku-machi, Takatsuki, Osaka, Japan. kenji.fukui@ompu.ac.jp.
Nature communications
|September 3, 2025
まとめ
KhpB (EloR) タンパク質は,KHとR3Hドメインを組み合わせてRNAを結合する. 構造データは,この細菌のRNA結合タンパク質が RNAとどのように相互作用し,その機能についての洞察を提供します.
科学分野:
- 分子生物学
- 構造生物学
- 生物化学
背景:
- KhpB (EloR) は,病原性細菌に見られるグローバルRNA結合タンパク質である.
- 核酸結合タンパク質に共通する独特のR3HとKHドメインを有する.
- KhpBの正確なRNA結合機構,特にそのR3Hドメインはよく理解されていません.
研究 の 目的:
- Thermus thermophilus KhpBによるRNA結合の構造的基礎を解明する.
- RNA認識におけるR3HとKHドメインの協力的役割を理解する.
主な方法:
- X線結晶学を用いて,RNAフリーとRNA結合のKhpB二元体の構造を決定した.
- 構造データを分析して,RNAとタンパク質の相互作用と形状の変化を特定する.
主要な成果:
- 結晶構造は,協力的なKHとR3Hドメインによって形成された複合RNA結合部位を明らかにした.
- KhpBは,少なくとも7つのヌクレオチドの単一のRNA分子に結合する.
- RNA結合は構造変化を誘導し,ドメイン間の裂け目を閉じ,主にRNAのリン酸骨格と相互作用する.
結論:
- KhpBはRNAの結合にユニークなドメインの協力を利用しています.
- KhpBのRNA相互作用メカニズムに関する構造的な洞察
- 他のR3Hドメインを含むタンパク質のRNA結合を理解するためのモデルを提供します.
関連する概念動画
Transcription Initiation
16.7K
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
16.7K
Eukaryotic RNA Polymerases
24.6K
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
24.6K
Cooperative Binding of Transcription Regulators
6.5K
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form...
6.5K
Types of RNA
64.8K
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
64.8K
Bacterial RNA Polymerase
30.3K
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...
30.3K
Translational Regulation
91
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
91


