DNAポリメラーゼβの指のサブドメインにあるトライアード相互作用は,ポリメラーゼ活性を制御する
Drew L Murphy1, Joachim Jaeger, Joann B Sweasy
1Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Journal of the American Chemical Society
|April 2, 2011
まとめ
DNA修復に不可欠なDNAポリメラーゼβ (polβ) は,その機能のためにC端末領域を必要とします. 特定の突然変異は,ポリメリゼーション活動に不可欠な重要な相互作用を明らかにしました.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- DNAポリメラーゼβ (polβ) は,塩基切除修復経路の中心に位置しています.
- 以前の研究では,ポリベータのC端部が機能に不可欠であることが示されていました.
研究 の 目的:
- DNAポリメリゼーションにおけるポリベータのC端末領域の役割を調査する.
- ポリベータ活動の基礎となる分子メカニズムを解明する.
主な方法:
- サイト・ディレクテッド・ミュータゲネシス (サイト・ディレクテッド・ミュータゲネシス) は,ポルベータのC端末領域のサイト・ディレクテッド・ミュータゲネシスである.
- ポリメラーゼの活性を測定するための運動実験.
- タンパク質の相互作用と形状の変化を研究するための分子モデリング.
主要な成果:
- C末端領域は,野生型のポリベータ活動に不可欠である.
- ポリメリゼーションには,指と手のひらのサブドメインの相互作用が必要です.
- E316R変異体は,ポリメリゼーション率の有意な低下を示したが,ニュクレオチド結合を保持していた.
- Arg182-Glu316の相互作用の混乱は,水害性ヒンジ領域の詰め込みと構成の変化に影響します.
結論:
- ポリベータのC末端領域は,DNAポリメリゼーションにおいて重要な役割を果たします.
- Arg182,Glu316,Arg333を含む特定のトライアード相互作用は,ポリベータ機能にとって極めて重要です.
- ポリメリゼーションの過程で,ニュクレオチド結合と核愛性の攻撃の間に非共性ステップが発生します.
関連する概念動画
01:31Proofreading
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Errors During Replication are Corrected by the DNA Polymerase Enzyme
01:43Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
02:10Translesion DNA Polymerases
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
02:13Cooperative Binding of Transcription Regulators
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 dimers that...
03:01The 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...
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...
02:37Restarting 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...