在DNA上的交易场所 - - 一个三点开关是从原酶到复制性DNA聚合酶的原始转移的基础
A Yuzhakov1, Z Kelman, M O'Donnell
1The Rockefeller University, New York, New York 10021, USA.
Cell
|February 16, 1999
概括
在大肠杆菌中,揭示了一种新的原酶到聚合酶切换机制. 这个过程涉及子单元和SSB蛋白来取代原酶,允许DNA聚合酶III全酶启动DNA合成.
科学领域:
- 分子生物学分子生物学
- 复制DNA复制DNA的复制
- 细菌学 细菌学是一门学科.
背景情况:
- 启动DNA复制需要由原酶合成的RNA原体.
- DNA聚合酶III全酶进行DNA延长.
- 调节原酶活性及其传递给DNA聚合酶对于复制忠实性至关重要.
研究的目的:
- 为了阐明通过DNA聚合酶III全酶的原酶移位的机制.
- 确定特定的子单元和辅助蛋白在这种过渡过程中的作用.
- 了解大肠杆菌中原料合成和扩展的调节.
主要方法:
- 生物化学测试用于研究蛋白质-DNA相互作用.
- 在实验室中复制原酶到聚合酶开关.
- 对蛋白质结合和位移动态的分析.
主要成果:
- 主酶紧紧地结合RNA原始酶,保护它们.
- 基因聚合酶III全酶的基亚单元取代了原酶.
- SSB蛋白调解了原酶和之间的相互作用,用于排位.
- 这便于将β滑动接器组装到RNA原料上.
结论:
- 一个保存的三蛋白开关机制调节了从原料合成到DNA延长的过渡.
- 这种切换涉及与SSB蛋白相互排斥的相互作用.
- 这些发现提供了对复制启动和延长机制协调的见解.
相关概念视频
Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
Lagging Strand Synthesis
During replication, the complementary strands in double-stranded DNA are synthesized at different rates. Replication first begins on the leading strand. Replication starts later, occurs more slowly, and proceeds discontinuously on the lagging strand.
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
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...
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...
Proofreading
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Errors During Replication are Corrected by the DNA Polymerase Enzyme


