ルテニウム複合DNA結晶の制御された脱水は,可逆的なDNAキンキングを誘導する
James P Hall1, Juan Sanchez-Weatherby, Cora Alberti
1Chemistry Department, University of Reading , Whiteknights, Reading, Berkshire RG6 6AD, United Kingdom.
Journal of the American Chemical Society
|November 14, 2014
まとめ
研究者らは脱水したDNAの原子構造を明らかにし,それが逆転的に水分化形態への移行が可能であることを示した. 結晶で見られるこのDNA構造の変化は,結晶のダイナミックな性質を強調しています.
科学分野:
- 構造生物学 構造生物学とは
- バイオフィジックス 生物物理学
- クリスタログラフィーです.
背景:
- DNAの構成は,水分濃度に依存することが知られている.
- 以前の研究では,異なる湿度下でのDNA構成を観察するために,繊維 difraktion に依存していました.
研究 の 目的:
- 脱水DNA複合体の原子レベルの結晶構造を決定する.
- 室温で脱水および水分化DNA形態の間の可逆的な移行を実証するために.
主な方法:
- 高解像度構造を入手するために,X線結晶学を用いた.
- 複数のデータセットを単一の結晶から室温で,相対湿度 (84-79%) の変動下で収集した.
- Λ-[Ru(TAP) 2(dppz) ](2+) の存在におけるDNA複合体 d ((TCGGCGCCGA) が研究されました.
主要な成果:
- 脱水したDNA複合体の結晶構造は,原子解像度で決定された.
- 脱水後にA/BハイブリッドからA-DNA形状への可逆的な移行が観察されました.
- DNAデュプレックスは,脱水時に,中央のステップキンク (22°から51°) が増加し,端末ベースが顕著に動いた.
結論:
- DNA結晶は,形状の変化を起こすことができるダイナミックなシステムです.
- 脱水はDNAの構造的な変化を誘導し,キンキングが増加します.
- この移行の可逆性により,DNA結晶のインシチュエーション実験の可能性が生まれます.
関連する概念動画
Overview of DNA Repair
35.6K
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...
35.6K
Fixing Double-strand Breaks
16.5K
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
16.5K
Nucleotide Excision Repair
42.9K
Overview
42.9K
Homologous Recombination
66.1K
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...
66.1K
DNA Topoisomerases
38.4K
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. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
38.4K
Restarting Stalled Replication Forks
6.6K
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,...
6.6K


