Fork Reversal
Fork Reversal - Related Videos
02:37
Restarting Stalled Replication Forks
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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...
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...
07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
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Cited by 11 •
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.
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The remodeling begins when newly synthesized strands separate from their original templates and anneal to each other. At the same time, the parental strands re-pair, creating a four-way junction behind the stalled synthesis site. This coordinated rearrangement changes the fork architecture without describing simple fork collapse, allowing the damaged or obstructed region to be managed as a structured DNA intermediate.
A regressed fork can reduce the exposure of vulnerable DNA at a site where synthesis has stalled. By reorganizing the newly made and parental strands, it creates a protected configuration that can also serve as a substrate for repair or lesion bypass. These properties connect fork reversal with genome preservation rather than treating stalling as an irreversible replication failure.
Fork reversal links the immediate response to a blocked replication fork with later repair or bypass decisions. Its remodeled structure provides an intermediate that can be acted on while replication stress is being managed. In genetics, this relationship is important because successful coordination limits chromosome instability, whereas defective handling of stalled forks can compromise genome integrity.
Analysis of Fork Reversal can clarify how cells respond when DNA synthesis encounters obstacles and how they preserve replication-associated DNA structures. It can also distinguish protective remodeling from outcomes associated with unresolved stress, such as chromosome instability. These insights help organize the relationship among fork protection, repair pathway engagement, lesion bypass, and maintenance of genome integrity.
Inherited repair defects provide an important genetic context for examining whether cells can properly manage stalled replication forks. Comparing fork responses in that context can connect altered repair capacity with impaired fork protection, reduced tolerance of replication stress, or greater chromosome instability. The process therefore offers a framework for relating inherited mutations to cellular genome-maintenance problems.
Cancer-associated mutations may alter the regulation of replication stress responses, making fork remodeling relevant to chromosome stability and disease biology. The same framework helps investigators consider how cells respond to therapies that target replication. Studying these relationships can clarify why defective fork management contributes to instability and how treatment-related replication obstacles engage repair or lesion-bypass responses.