相关实验视频
Updated: Jul 20, 2026

12:02
Molecular Evolution of the Tre Recombinase
Published on: May 29, 2008
概括
Tn3溶解酶有效地重组DNA部位,形成简单的链状环. 拓分析表明,在转位过程中,酶可能无法保持连续的DNA接触.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 特定位置的重组对于各种生物过程中的DNA操纵至关重要.
- Tn3溶解酶通过与特定的重组 (res) 位点结合来调节DNA重组.
- 了解Tn3溶解酶的机制是破译DNA拓和酶-DNA相互作用的关键.
研究的目的:
- 为了研究Tn3溶解酶的体外重组机制.
- 分析Tn3溶解酶介导重组的拓产物.
- 为了阐明Tn3溶解酶的DNA结合和转位特性.
主要方法:
- 在体外再组合测试中,使用具有直接重复复位点的等离子体进行测试.
- 使用凝电泳分析对DNA拓产物 (链) 的分析.
- 基质超线圈密度和酶度的系统变化.
- 使用多站点基板来研究位置效应和转位.
主要成果:
- Tn3溶解酶从两个直接重复的反应部位生成单个相互连接的链状环.
- 产品连环结构在不同的超线圈密度中保持稳定.
- 在四个站点的基板中观察到对邻近的资源站点进行重组的偏好.
- 拓测试表明,TN3溶解酶在转位过程中可能无法保持连续的DNA接触.
结论:
- Tn3溶解酶表现出一种简单而强大的重组机制,形成稳定的连锁产物.
- 该酶显示位置偏好,表明对DNA位点的系统搜索.
- 新的拓学分析提供了证据,证明了在溶解酶转位过程中持续的DNA-蛋白质接触.
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...
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...
Restarting 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...
Overview of Transposition and Recombination
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
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...

