人类DNA聚合酶 Eta 的结构和机制
Christian Biertümpfel1, Ye Zhao, Yuji Kondo
1Laboratory of Molecular Biology, NIDDK, NIH, 9000 Rockville Pike, Building 5, Room B103, Bethesda, Maryland 20892, USA.
Nature
|June 26, 2010
概括
Xeroderma pigmentosum变体 (XPV) 是由于DNA聚合酶eta (Poleta) 缺乏导致的. 结构洞察力揭示Poleta稳定了受损的DNA,使复制成为可能,并为了解XPV突变提供了基础.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- Xeroderma pigmentosum变体 (XPV) 是一种与DNA聚合酶eta (Poleta) 缺乏相关的人类综合征.
- 波莱塔对于复制紫外线 (UV) 辐射损伤的DNA至关重要,特别是胺二聚体.
研究的目的:
- 通过紫外线诱导的胺二次体在DNA合成过程中阐明人类Poleta的结构机制.
- 了解Poleta如何在分子层面上发挥作用,以克服DNA损伤.
主要方法:
- 高分辨率晶体学被用来捕捉人类Poleta结构在DNA合成的四个不同的阶段.
- 结构分析的重点是Poleta与cis-syn环丁丁胺二元体的相互作用.
主要成果:
- 波莱塔作为一个"分子",使受损的DNA稳定在B型形状.
- 一个扩大的活性位点促进了两金属离子催化,并容纳了精确立体化学的胺二次体.
- 保存的残留物与DNA损伤和传入的核酸形成关键的键,帮助转化合成.
结论:
- 通过识别Poleta的稳定或催化功能的中断,确定的结构合理化了导致XPV的八种误解突变.
- 这些发现提供了对Poleta在复制具有挑战性的DNA结构,如D循环和脆弱部位的更广泛作用的见解.
相关概念视频
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Overview
02:40DNA 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.
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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...
03:01The 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...
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Eukaryotic replication follows many of the same...
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01:29Replication 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...
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Eukaryotic replication follows many of the same...