在个别DNA聚合酶复合体中测量转位阶段的动力学
Kate R Lieberman1, Joseph M Dahl, Ai H Mai
1Biomolecular Engineering, University of California, Santa Cruz, 95064, United States. krlieberman@gmail.com
Journal of the American Chemical Society
|October 30, 2012
概括
使用纳米孔技术研究了菌体phi29 DNA聚合酶 (DNAP) 转位动态. 活动部位附近的DNA序列会影响DNAP转位的能量格局.
科学领域:
- 生物化学 生物化学
- 纳米技术 纳米技术
- 分子生物学分子生物学
背景情况:
- 菌体phi29 DNA聚合酶 (DNAP) 与DNA形成复合体,在转移前和转移后的状态之间波动.
- 这些动态对于理解DNAP催化循环至关重要.
研究的目的:
- 为了研究phi29 DNAP-DNA复合体中转位步骤的随机动力学.
- 分析管理转移过程的能源格局.
主要方法:
- 使用单分子观测的phi29 DNAP-DNA复合体在一个α-hemolysin纳米孔.
- 采用实时离子电流测量和自相关函数分析来确定过渡速率.
主要成果:
- 观察到两个离散状态 (转移前和转移后) 之间的波动,具有单指数衰变动力学.
- 提取了状态之间的前向和逆向转变速率,作为应用电压的函数.
- 证明在活性部位附近的DNA序列调节了转位状态的能量井.
结论:
- 该研究通过分析其随机动态,提供了对DNAP转位步骤机制的洞察.
- 活点DNA序列在塑造能量格局和DNAP转移的过渡状态方面发挥着重要作用.
相关概念视频
The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
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...
Real Time RT-PCR
Real-time reverse transcription-polymerase chain reaction, or Real-time RT-PCR, is an analytical tool used to determine the expression level of target genes. The method involves converting mRNA to complementary DNA with the help of an enzyme known as reverse transcriptase, followed by the PCR amplification of the cDNA. These two processes can be performed simultaneously in a single tube or separately as a two-step reaction.
The real-time quantification of the number of amplified products is...
The real-time quantification of the number of amplified products is...
Replication in Prokaryotes
DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules.
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
Replication in Prokaryotes
Overview
DNA Replication
DNA replication involves the separation of the two strands of the double helix, with each strand serving as a template from which the new complementary strand is copied. After replication, each double-stranded DNA includes one parental or “old” strand and one “new” strand. This is known as semiconservative replication. The resulting DNA molecules have the same sequence and are divided equally into the two daughter cells.
Replication in Prokaryotes
DNA replication uses a large number of...
Replication in Prokaryotes
DNA replication uses a large number of...


