Fork Stalling
Fork Stalling - Related Videos
02:37
Restarting Stalled Replication Forks
0 Views •
2020
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...
02:37
Restarting Stalled Replication Forks
0 Views •
2023
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...
07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
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Cited by 10 •
2010
The fate of the replisome following a collision with a head-on RNA polymerase (RNAP) is unknown. We find that the replisome stalls upon collision with a head-on RNAP, but resumes elongation after displacing the RNAP from DNA. Mfd promotes replication restart by facilitating displacement of the RNAP after the collision.
01:02
The DNA Replication Fork
0 Views •
2020
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...
01:02
The DNA Replication Fork
0 Views •
2023
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...
FAQs
Obstacles such as DNA lesions, tightly bound proteins, repetitive sequences, or insufficient nucleotides interfere with the coordinated actions of helicase and DNA polymerase. When helicase continues unwinding while polymerase synthesis is impaired, the replication machinery becomes uncoupled. This disruption can increase the risk of chromosome damage unless cellular responses stabilize the affected fork.
Replication-checkpoint signaling acts as a protective response when fork progression is disrupted. It stabilizes the stalled structure, limits additional damage, and creates conditions that support repair or later restart. This coordination is important because an unmanaged stalled fork may contribute to chromosome breaks, whereas checkpoint control helps preserve genome stability during replication stress.
Restart can proceed through mechanisms including template switching and homologous recombination. Template switching allows replication to use an alternative matching template, while homologous recombination provides a pathway for recovering replication intermediates through sequence-based repair. These mechanisms help the cell bypass or repair the underlying problem and restore chromosome duplication without immediately converting the stall into a break.
A useful analysis considers both the source of the obstacle and the cellular response to it. Researchers can distinguish effects associated with lesions, protein-bound DNA, repetitive sequences, or nucleotide limitation, then examine checkpoint stabilization, repair, and restart pathways. The resulting interpretation should connect fork behavior with broader outcomes such as chromosome breaks, mutations, and genome stability.
Fork stalling is a key model for understanding how cells protect chromosomes while copying DNA. If stabilization, repair, or restart fails, replication problems can contribute to breaks and mutations. Consequently, research on this process informs the biology of genome maintenance, developmental disorders, and cancer, where replication-associated damage can influence disease development and cellular behavior.
Cancer research examines fork stalling because DNA-damaging therapies can challenge replication and expose weaknesses in checkpoint, repair, or restart responses. Studying how cells manage these stalled structures helps connect treatment-related replication stress with chromosome damage and mutation. The same framework also clarifies why genome-stability pathways are relevant when interpreting cellular responses to therapy.