DNA損傷の切除のための前例のない核酸捕獲機構
Emily H Rubinson1, A S Prakasha Gowda, Thomas E Spratt
1Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, USA.
Nature
|October 8, 2010
まとめ
バシルス・セレウスAlkD DNAグリコシラーゼは,固形外傷を独特の溶媒露出方向で捕捉することによって,損傷したDNAを修復します. このメカニズムは,ゲノム保護とがん治療の洞察に不可欠な細胞毒性N3-メチラデニン塩基の除去を促進します.
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.
- 構造生物学 構造生物学とは
背景:
- DNAグリコシラゼは,損傷したピューリン基を除去し,ゲノムの完全性にとって不可欠です.
- これらの酵素はDNA修復経路において重要な役割を果たしますが,がんのアルキレーション療法に干渉することがあります.
- グリコシラーゼの特異性を理解することは,治療戦略の改善の鍵です.
研究 の 目的:
- バシルス・セレウスAlkDの構造的基礎を解明する.DNAグリコシラーゼ特異性.
- AlkDがアルキル化ピューリン基を認識し,処理するメカニズムを調査する.
- DNA修復に関する構造的な洞察と,がん治療におけるその影響を提供するためです.
主な方法:
- X線結晶学により,改変DNAの複合体AlkDの構造を決定する.
- 塩基転移と触媒活性を分析するための生化学的分析.
- DNAとタンパク質の相互作用と酵素機構の構造分析.
主要な成果:
- 結晶構造は,AlkDが溶媒に曝露された方向で外螺旋的な病変を捕捉することを明らかにします.
- このユニークな結合方式は,N3およびN7アルキル化塩基の水解を容易にする.
- AlkDは,HEATの繰り返しを利用してDNAの骨幹を歪め,不適切な塩基対の検出をインターキャラなしで可能にします.
結論:
- AlkDは,既知の他のグリコシラゼと異なるDNA修復の独特なメカニズムを使用しています.
- 酵素の構造は,アルキル化ピューリンの塩基切除修復のモデルを提供します.
- 発見は,がんアルキレーション療法における抵抗メカニズムを克服するための洞察を提供します.
関連する概念動画
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Nucleotide Excision Repair
Overview
Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Nucleotide Excision Repair
Overview
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...


