病原性サブゲノムフラビウイルスRNA (sfRNA) 生産の構造的基礎
Erich G Chapman1, David A Costantino, Jennifer L Rabe
1Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, Aurora, CO 80045, USA.
Science (New York, N.Y.)
|April 19, 2014
まとめ
病原性フラビウイルスは,宿主細胞の防御を回避する抵抗性RNA構造を生成する. この研究は,このRNAの結晶構造を明らかにし,ウイルスの分解を阻害し,感染を促進するユニークなリング状の折りたたみを発見しました.
科学分野:
- ウイルス学 ウイルス学 ウイルス学
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- フラビウイルスは,世界的な健康にとって重大な脅威です.
- サブゲノムフラビウイルスRNAs (sfRNAs) は宿主細胞の外核酵素の分解に抵抗することで,ウイルス感染を可能にします.
- Xrn1エクソヌクレアゼに対するsfRNA耐性のメカニズムは以前は知られていなかった.
研究 の 目的:
- フラビウイルスRNAにおけるXrn1耐性の構造的基礎を決定する.
- sfRNAが宿主細胞の分解を回避するメカニズムを解明する.
主な方法:
- 完全なXrn1耐性フラビウイルスRNAの3D構造を決定するX線結晶学.
- 保存されたヌクレオチドとRNAトポロジーの分析.
- sfRNA形成に対する構造的障害の影響を評価するための機能検査.
主要な成果:
- 結晶構造は,相互に織り交わされた擬似結び目を持つコンパクトなRNAの折りたたみを示しています.
- RNAは環状の形状を形成し,その5'端は環を通過します.
- 保存されたヌクレオチドは,この特定の構造を維持するために不可欠です.
- この構造の破壊は,感染中にsfRNAの形成を無効にします.
結論:
- sfRNAの形成は,特定の保存されたRNAの折りたたみに依存しています.
- このRNA構造は,宿主細胞外核酵素Xrn1.1.と直接相互作用し,それを阻害する.
- RNAのトポロジーは,Xrn1ヘリケース活性を混乱させ,RNAの分解を防ぐ.
関連する概念動画
01:29Subviral Agents
933
Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...
933
01:29Viruses with RNA Genomes
1.5K
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
1.5K
02:30siRNA - Small Interfering RNAs
13.4K
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...
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...
13.4K
02:28Leaky Scanning
4.5K
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...
4.5K
01:26Size and Structure of Viral Genomes
1.2K
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
1.2K
00:56Viral Structure
59.0K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
59.0K