RADAR抗ファージの超分子組成の分子基礎

Yina Gao¹, Xiu Luo¹, Peipei Li²

¹CAS Key Laboratory of Infection and Immunity, National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.

Cell

|February 10, 2023

まとめ

バクテリアのRADAR防御はRNAを編集するためにRdrAとRdrBタンパク質を使用します. Cryo-EM構造は,これらのタンパク質がRNAをトランスロケーションし,改変する方法を明らかにし,アンチファージ機構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:

アデノシンからイノシンへのRNA編集は,細菌の抗菌体防御に関与しています.
RADARシステムはアデノシントリフォスファターゼ (RdrA) とアデノシンデアミナーゼ (RdrB) を含む.

研究の目的:

RADARシステムの構造的基礎を明らかにする.
バクテリアの抗菌体防御におけるRNA転移と脱アミネーションの仕組みを理解する.

主な方法:

RdrA,RdrB,およびそれらの複合体の構造を決定するために,冷凍電子顕微鏡 (cryo-EM) が使用されました.
システムの機能的側面を評価するために生化学的測定が行われました.

主要な成果:

RdrBはドデカメリックケージを形成し,RdrAはテトラデカメリック (自己抑制) とヘプタメリック (活性) リングとして存在します.
構造データは,RdrAによるRNA転位がATP結合と結合することを示唆している.
複数のRdrAリングがRdrBケージにドッキングし,結合RNAの転位とデアミネーションのための触媒部位を並べます.

結論:

この研究は,RNA編集と抗菌素防御のための新しい酵素結合のメカニズムを明らかにしています.
RdrAとRdrBの超分子組成は,RADARシステムの機能に不可欠です.

キーワード:

アトピーゼアデノシン・デアミナーゼアデノシンからイノシンアンチファージ防御レーダー RNA編集超分子組成

さらに関連する動画

08:34

MS2-Affinity Purification Coupled with RNA Sequencing in Gram-Positive Bacteria

Published on: February 23, 2021

6.8K

13:31

Novel Atomic Force Microscopy Based Biopanning for Isolation of Morphology Specific Reagents against TDP-43 Variants in Amyotrophic Lateral Sclerosis

Published on: February 12, 2015

8.8K

関連する概念動画

01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...

01:23

The Antiviral System of Bacteria and Archaea: CRISPR

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...

02:41

Protein Complex Assembly

10.7K

Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...

10.7K

02:53

CRISPR and crRNAs

17.2K

Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...

17.2K

01:30

Lytic Cycle of Bacteriophages

71.4K

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...