相关实验视频
Updated: Jul 15, 2026

09:06
Preparation of DNA-crosslinked Polyacrylamide Hydrogels
Published on: August 27, 2014
概括
乙甲基 (BAA) 与超卷聚合体中的未配对DNA基发生反应. 令人惊的是,邻近的DNA序列也发生了反应,表明影响DNA构造的位置效应.
科学领域:
- 分子生物学分子生物学
- DNA结构和动力学
- 生物化学 生物化学
背景情况:
- 超绕的DNA可以采用非正规结构.
- 众所周知,类似于poly (dG) -poly (dC) 的同纯素-同胺基序列形成了不寻常的DNA结构.
- 乙 (BAA) 是一种化学探针,它专门与未配对的DNA基发生反应.
研究的目的:
- 为了研究与乙化的超卷聚合物中的多-多-多序列的反应性.
- 为了确定邻近的DNA序列是否会受到多DG-多DC通道的存在的影响.
- 为了阐明由特定序列诱导的超卷DNA的构造变化.
主要方法:
- 合成了含有poly (dG) -poly (dC) 序列的超卷状等离子体DNA.
- 等离子体DNA与乙 (BAA) 的反应.
- 分析BAA引证,以确定反应的DNA基和它们的位置.
主要成果:
- 超卷聚合物中的poly (dG) -poly (dC) 序列与BAA发生了反应,证实了其未配对的基区域.
- 意想不到的是,与多样性 (dG) -多样性 (dC) 通道相邻的 (3') DNA 序列也与BAA发生了反应.
- 在相邻的序列中,这种反应发生在同一个超螺旋等离子体分子中.
- 邻近序列的反应性取决于它们相对于多 (dG) -多 (dC) 段的位置,而不是它们的特定序列组成.
结论:
- 超绕的DNA中的多基 (dG) -多基 (dC) 序列可以诱导延伸到相邻DNA区域的构造变化.
- 一个位置效应,而不是特定序列的相互作用,决定了邻近DNA的改变形状.
- 这些发现突出了特定DNA序列和超级卷对局部DNA结构和可访问性的影响.
相关概念视频
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...
Translesion 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...
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...
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...
Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
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...

