ユカリオットの複製体分解を制御する保存されたメカニズム
Michael Jenkyn-Bedford1, Morgan L Jones1, Yasemin Baris1
1MRC Laboratory of Molecular Biology, Cambridge, UK.
Nature
|October 26, 2021
まとめ
DNA複製の最終段階である複製体分解は,CMGヘリケーゼのユビキティレーションによって制御される. 複製フォークのDNAは,早すぎるCMGの普遍化を防止し,ゲノムの安定性を確保します.
科学分野:
- 分子生物学
- 遺伝学
- 生物化学
背景:
- 複素体分解は,CMGヘリケイズ普遍化によって開始された真核DNA複製を完了する.
- 複製フォークDNAによって媒介されるフォークの崩壊を防ぐために,複製の終了前にユビキティレーションが抑制されます.
- E3リガスが延長されたレプシソームと終了したレプシソームを区別するメカニズムは不明である.
研究 の 目的:
- SCFDia2とCUL2LRR1リガゼによるCMGの選択的汎用化の構造的基礎を解明する.
- 複製フォークDNAが延長時にCMGの普遍化を抑制する方法を理解する.
主な方法:
- 発芽中の酵母とヒトレプリソーム-E3リガゼ複合体の高解像度冷凍電子顕微鏡 (冷凍-EM)
- CMGヘリケーズとのDia2とLRR1の相互作用の構造分析
主要な成果:
- 構造は,Dia2とLRR1のLRRドメインが,MCM3/MCM5を含むCMGに保存されたサイトを結合することを明らかにする.
- このLRR-MCMの相互作用は,レプリソームの解体には極めて重要です.
- 複製フォークで排除されたDNA鎖は,この相互作用をステリックに阻害し,延長中にCMGの汎用化を防ぐ.
結論:
- 保存されたメカニズムは,DNA媒介による CMG ユビキティレーションを終了前に抑制し,レプリソームの解体を調節する.
- DNAは 早期分解を防ぐことで 複製体の整合性を維持する上で 重要な役割を果たします
さらに関連する動画
11:19Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System
Published on: August 21, 2016
9.2K
08:53Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method
Published on: May 2, 2025
545
関連する概念動画
The Replisome
36.0K
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 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...
36.0K
Restarting Stalled Replication Forks
6.0K
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,...
6.0K
Homologous Recombination
55.6K
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...
55.6K
Replication in Eukaryotes
177.4K
Overview
177.4K
Nucleosome Remodeling
9.9K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.9K
Coordination of Gene Expression Processes in Bacteria
228
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
228
