相关实验视频
Updated: Sep 4, 2025

09:25
In vitro Reconstitution of the Active T. castaneum Telomerase
Published on: July 14, 2011
11.8K
聚合酶α-酶结合的CST的结构
Yao He1,2, He Song1, Henry Chan1
1Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA.
Nature
|July 13, 2022
概括
这项研究揭示了将DNA聚合酶α-初酶 (PolαPrim) 和CTC1-STN1-TEN1 (CST) 引入端粒的结构基础. 这些发现揭示了染色体末端的DNA合成协调.
科学领域:
- 分子生物学
- 结构生物学
- 遗传学
背景情况:
- 端粒是染色体末端的保护帽, 对于基因组的稳定性至关重要.
- 端粒维护涉及G链合成的端粒酶和C链合成的DNA聚合酶α-原酶 (PolαPrim).
- 对PolaPrim和CTC1- STN1- TEN1 (CST) 复合物的招募机制在结构上仍未确定.
研究的目的:
- 阐明PolαPrim和CST在端粒末端的结构基础.
- 提供对G链和C链DNA合成在端粒的协调的见解.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定Tetrahymena CST,端粒酶全酶和PolαPrim的结构.
- 核磁共振 (NMR) 光谱以表征结合相互作用.
主要成果:
- 结构显示Tetrahymena Ctc1通过灵活的动机与端粒酶子单元p50结合.
- 波拉1的PolaPrim子单元与Ctc1和Stn1结合,Ctc1形成了G链DNA进入波拉1活性部位的入口.
- 获得了端粒酶核核核蛋白,p50,CST和PolαPrim复合物的全面结构快照.
结论:
- 这项研究提供了关于CST和PolαPrim对端粒的首次结构性见解.
- 这些发现阐明了染色体末端G链和C链合成之间交换的分子机制.
- 这些结构数据为了解端粒复制和维护提供了基础.
相关概念视频
Telomeres and Telomerase
23.9K
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...
23.9K
Translesion 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
The Replisome
34.6K
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 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...
34.6K
Replication in Eukaryotes
171.6K
Overview
171.6K
Lagging Strand Synthesis
54.0K
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...
54.0K
Mechanism of Conjugation
112
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
112

