同方向的复制-转录冲突导致复制重新启动
Houra Merrikh1, Cristina Machón, William H Grainger
1Department of Biology, M.I.T., Cambridge, Massachusetts 02139, USA.
Nature
|February 26, 2011
概括
同向转录与DNA在体内复制发生冲突,破坏了这一过程. 这需要复制重启蛋白质,与体外发现相反,突出显示了DNA复制和转录的体内复杂性.
科学领域:
- 分子生物学分子生物学
- 基因组学就是基因组学.
- 微生物学 微生物学
背景情况:
- DNA复制和转录可能发生冲突,特别是在滞后链上,可能导致基因组不稳定.
- 基因通常编码在领先链上,用于协同定向的复制和转录,以最大限度地减少正面冲突.
研究的目的:
- 为了研究同向转录复制遭遇的体内后果.
- 确定复制重启蛋白在解决这些冲突中的作用 Bacillus subtilis.
主要方法:
- 研究了快速生长的细菌细菌细胞.
- 在冲突部位观察到复制性酶和复制重启蛋白质的关联.
- 分析了转录依赖蛋白质的招募.
主要成果:
- 同向转录与体内复制发生冲突,特别是在高度转录的rRNA基因中.
- 复制重启蛋白和复制性酶以转录依赖的方式被招募到冲突地点.
- 在体内,复制重启机制对于解决正面冲突和共同方向冲突至关重要,与体内观测不同.
结论:
- 同向转录在体内对DNA复制构成了重大挑战.
- 复制重启机制在解决活细胞中转录和复制之间的冲突方面发挥着至关重要的作用.
- 这些发现解释了辅助蛋白对于复制重新启动和复制细胞进展的必要性.
相关概念视频
01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
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...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
02:31Replication in Eukaryotes
Overview