Related Experiment Video
Updated: Aug 27, 2025
11:19
Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System
Published on: August 21, 2016
9.1K
Creation and resolution of non-B-DNA structural impediments during replication
Christopher Mellor1, Consuelo Perez1, Julian E Sale1
1Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK.
Critical Reviews in Biochemistry and Molecular Biology
|September 28, 2022
Summary
DNA secondary structures impede DNA replication. This study examines how these structures form and how the replisome resolves them to prevent replication stress and ensure genome duplication.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- DNA replication requires smooth progression of the replisome.
- Non-B-form secondary structures are frequent impediments during DNA replication.
- These structures can cause replication stress, necessitating active resolution.
Purpose of the Study:
- To discuss the forces driving non-B-form DNA secondary structure formation.
- To review evidence of secondary structures as a source of replication stress.
- To examine how these structures are sensed and resolved by the replisome.
Main Methods:
- Review of recent advances in molecular and structural biology.
- Analysis of yeast and human replisome mechanisms.
- Examination of DNA secondary structure formation and resolution pathways.
Main Results:
- Non-B-form DNA secondary structures are abundant impediments during replication.
- Replication stress arises frequently from these DNA structures.
- The core replisome and accessory factors actively counter these structures.
Conclusions:
- Understanding non-B-form structure formation is crucial for comprehending replication stress.
- The replisome possesses mechanisms to sense and resolve DNA secondary structures.
- Active resolution of these structures is essential for accurate genome duplication.
Related Concept Videos
01:02The DNA Replication Fork
36.5K
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...
36.5K
02:37Restarting Stalled Replication Forks
5.9K
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,...
5.9K
01:03Single-Strand DNA Binding Proteins
14.8K
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
14.8K
02:04Fixing Double-strand Breaks
12.8K
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...
12.8K
03:01The Replisome
34.5K
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...
34.5K
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