帕拉梅PolX DNA聚合酶的忠实性,专业化和进化参与编程的双链断裂DNA修复
Nourisson Antonin1,2, Missoury Sophia1, Lucas-Staat Soizick1
1Unit of Architecture and Dynamics of Biological Macromolecules, Université Paris Ci té, CNRS UMR 3528, 25-28 rue du Docteur Roux, Institut Pasteur, 75015 Paris, France.
Nucleic acids research
|August 19, 2025
概括
帕拉梅四素修复DNA双链断裂 (DSBs) 使用忠实的DNA聚合酶X (PolXs). 这些酶可能代表甲基动物Polβ和Polλ之间的进化联系,对植物DNA修复有影响.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 在Paramecium的性繁殖过程中,DNA双链断裂 (DSB) 对宏核发育至关重要.
- 帕拉梅四角利用非同类末端连接 (NHEJ) 进行精确的DSB修复.
- 在Paramecium中存在四个DNA聚合酶X (PolX) 家族基因,其中一个与NHEJ蛋白相关.
研究的目的:
- 为了生物化学地表征所有四种Parametium PolX酶.
- 研究这些PolX酶的进化起源和功能专业化.
- 了解它们在DNA修复中的高保真性的结构基础.
主要方法:
- 生物化学测试以评估酶活性和忠实性.
- 位点导向的突变发生以探测酶功能.
- 人类Polλ突变体的X射线晶体学结合了帕拉梅序列.
主要成果:
- 这四种Paramecium PolX酶都在DNA修复中表现出高保真度.
- 这些酶分为两种功能类别,表明它们具有专门的作用.
- 结构分析表明Paramecium PolXs可能是甲基动物Polβ和Polλ之间的进化中间体.
结论:
- 帕拉梅PolX酶在宏核发育过程中对编程的DSB修复起着至关重要的作用.
- 这些酶为DNA修复机制的演变提供了洞察力.
- 这些发现与了解植物PolX酶在DSB修复中的重要性有关,包括CRISPR-Cas9应用.
相关概念视频
02:31Homologous Recombination
51.7K
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...
51.7K
02:10Translesion DNA Polymerases
10.1K
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...
10.1K
02:04Fixing Double-strand Breaks
12.9K
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
12.9K
01:31Proofreading
6.6K
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...
Errors During Replication are Corrected by the DNA Polymerase...
6.6K
02:31Replication in Eukaryotes
172.0K
Overview
172.0K
01:02Long-patch Base Excision Repair
7.2K
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
7.2K