8-オキシグアナインを含むDNA塩基対のダイナミックな行動
Xiaolin Cheng1, Catherine Kelso, Viktor Hornak
1Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA.
Journal of the American Chemical Society
|October 6, 2005
まとめ
DNAの酸化,特に8-オクソグアナイン (8-オクソG) は,DNAの柔軟性を高め,塩基挤出を促進します. 8-oxoG:Aのような不一致は,自発的なanti-to-syn移行を経験し,DNA修復酵素の選択性に影響を与えます.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- コンピュータ生物学 コンピュータ生物学
背景:
- DNA修復メカニズムは,ゲノムの完全性を維持するために不可欠です.
- 酸化性DNA損傷,特に8-オクソグアニン (8-オクソG) は一般的な病変です.
- 塩基挤出は,DNA損傷の認識と修復の重要なステップです.
研究 の 目的:
- 酸化的ダメージを含むDNA複合体の構成動態を調査する.
- 塩基ペアリングとシーケンスの文脈が8oxoGの構成と挤出にどのように影響するか理解する.
- 修復酵素による損傷したDNAの認識の基礎となるメカニズムを解明する.
主な方法:
- 13メルのDNA二重複の無制限分子ダイナミクスシミュレーション.
- DNAの構造的変動,柔軟性,塩基挤出障壁の分析.
- 塩基対の幾何学と核酸化物の構成変異の調査.
主要な成果:
- デュプレックスDNAの8-oxoGは,通常のグアニンと比較して,柔軟性が向上し,塩基挤出に対するバリアが低下しています.
- 8-oxoG:A不一致は,重要な構造的不安定性を示し,自発的なanti-to-syn移行を経験しています.
- 8-オクソGのシン構成は熱力学的に好ましいものであり,ステリックおよび静電的要因によって引き起こされる.
- 移行経路と速度は配列に依存しており,酵素特異性についての洞察を提供します.
結論:
- 酸化によるダメージはDNAのダイナミクスと均衡構造を変化させ,修復を容易にする.
- 形状の柔軟性と配列の文脈は,DNA損傷の認識において重要な役割を果たします.
- これらの発見は,損傷したDNAに対するDNA修復酵素の選択的作用に関する機械的洞察を提供します.
さらに関連する動画
12:15Quantification of three DNA Lesions by Mass Spectrometry and Assessment of Their Levels in Tissues of Mice Exposed to Ambient Fine Particulate Matter
Published on: May 29, 2019
05:13Quantifying the Level of 8-oxo-dG Using ELISA Assay to Evaluate Oxidative DNA Damage in MCF-7 Cells
Published on: May 24, 2024
関連する概念動画
DNA Topoisomerases
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
DNA Damage can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Spontaneous and Induced Mutations
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
