在 prokaryotic 和 eukaryotic DNA 聚合酶中保存的 3'----5' 外核酶活性位
A Bernad1, L Blanco, J M Lázaro
1Centro de Biologia Molecular (CSIC-UAM), Universidad Autónoma, Madrid, Spain.
Cell
|October 6, 1989
概括
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科学领域:
- 分子生物学分子生物学
- 酶学 是一种酶学.
- 进化生物学 进化生物学
背景情况:
- DNA聚合酶具有关键的3'到5'外核酶活性,用于DNA修复和复制.
- 序列同质性表明,在原生和真核DNA聚合酶中保留了活性位点.
研究的目的:
- 研究DNA聚合酶中3'至5'外核酶活性位点的进化保存.
- 通过在phi 29 DNA聚合酶中使用位点定向突变发生的方法来验证功能性保存.
主要方法:
- 对大肠杆菌DNA聚合酶I与其他聚合酶的氨基酸序列同质分析.
- 在phi 29 DNA聚合酶中预测的外核酶活性位点的位点导向突变发生.
主要成果:
- 确定了对金属结合,DNA结合和 prokaryotic 和 eukaryotic DNA 聚合酶中的催化作用至关重要的保存的氨基酸区域.
- 菲29DNA聚合酶的突变性取消了其3'到5'外核酶活性,证实了功能性保存.
- 证明了这一催化领域的高程度的进化保护.
结论:
- 3'到5'外核酶活性位点在各种DNA聚合酶中高度保留.
- 对于 prokaryotic 和 eukaryotic DNA 聚合酶,一种模块化组织的酶性活动被提出.
相关概念视频
Replication in Eukaryotes
Overview
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...
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...
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
Replication in Eukaryotes
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...


