安定したRAG1-RAG2-DNA複合体で,V(D) J分裂に活性化しています

K Hiom¹, M Gellert

¹Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.

Cell

|January 10, 1997

まとめ

RAG1およびRAG2タンパク質は,DNA再結合部位で安定した複合体を形成し,V(D) J再結合を開始します. この複雑なコンプレックス.

科学分野:

分子生物学は分子生物学である.
免疫学免疫学とは
遺伝学遺伝学とは

背景:

V(D) J再結合は,適応性免疫にとって極めて重要です.
RAG1とRAG2のタンパク質は,特定の部位でDNAを分裂することによって,このプロセスを開始します.

研究の目的:

RAG1/RAG2タンパク質と再結合信号配列の間の初期相互作用を調査する.
V(D) J再結合で形成されるタンパク質-DNA複合体の構造と機能を特徴付ける.

主な方法:

タンパク質-DNA結合測定は,特定の相互作用を証明するために行われます.
生物化学的分析により,分裂活動と複合体の安定性を分析する.
二等性カチオン依存性研究.

主要な成果:

RAG1とRAG2は,再結合信号配列に特異的に結合し,安定した複合体を形成します.
この複合体は,保存されたヘプタマーとノンアマーモチーフとRAGタンパク質の両方を必要とします.
複合体はDNAをノックまたはヘアピンすることができ,その活動は二価イオン (Ca2+,Mg2+,Mn2+) に依存する.
複合体は,DNAの分裂後に不安定化し,解離する.

結論:

RAG1/RAG2によってV(D) J再結合部位で安定した分裂複合体が形成されます.
この複合体は,V(D) J再結合経路における重要な中間物質である.
二対子カチオンは,RAG複合体の分裂活動を調節する上で重要な役割を果たします.

さらに関連する動画

10:11

Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG

Published on: July 26, 2024

07:37

Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase

Published on: September 27, 2024

関連する概念動画

00:55

DNA Helicases

DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...

03:01

The Replisome

DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...

02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...

02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...

01:03

Single-Strand DNA Binding Proteins

For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...