优化的末端堆叠为人类端粒G-四重复DNA提供了N-甲基美索氨酸IX的特异性
John M Nicoludis1, Stephen T Miller, Philip D Jeffrey
1Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States.
Journal of the American Chemical Society
|November 28, 2012
概括
N-甲基中氨酸IX (NMM) 通过调整其形状,融入核心并与离子对齐来选择性地结合并行G-四重复体 (GQ). 这就解释了NMM.
科学领域:
- 结构生物学 结构生物学
- 生物化学 生物化学
- 药用化学 医学化学
背景情况:
- 在双重DNA上,N-甲基介质氨酸IX (NMM) 对G-四重复 (GQ) 具有很高的选择性.
- NMM证明了对平行与反平行GQ折叠的选择性.
研究的目的:
- 确定NMM和人类端粒DNA (Tel22) 之间的复合物的X射线晶体结构.
- 阐明NMM对平行GQ结构的选择性的分子基础.
主要方法:
- 在1.65 Å和2.15 Å分辨率的NMM-Tel22复合物的X射线晶体学.
- 对NMM-Tel22结合相互作用的生物化学分析.
主要成果:
- 获得了迄今为止人类端粒GQDNA的最高分辨率结构.
- 生物单元揭示了一个Tel22二元体,5'-5'堆叠并行GQs被NMM封顶.
- NMM的宏循环几何学适应G-四度,N-甲基组适应GQ核心并与离子对齐.
- 绝缘冲突解释了NMM缺乏与双重DNA和反平行GQs的结合.
- NMM-Tel22的结合是疏水的,而不是静电的.
结论:
- 结构和生化数据解释了NMM对平行GQ的异常选择性.
- 观察到的特征为设计具有高亲和力和选择性的新四重复合联体提供了基础.
相关概念视频
Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
Mismatch Repair
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
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...


