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Updated: Oct 21, 2025
07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 29, 2010
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Bypass of complex co-directional replication-transcription collisions by replisome skipping.
Jan-Gert Brüning1, Kenneth J Marians1
1Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
Nucleic Acids Research
|September 1, 2021
Summary
DNA replication encounters obstacles from colliding RNA polymerases (RNAPs). The replisome bypasses these, using mRNA or new primers, with factors like Rep and Mfd aiding continuous DNA synthesis.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Collisions between DNA replication machinery (replisome) and RNA polymerases (RNAPs) impede DNA replication.
- These collisions can be head-on or co-directional, with distinct resolution mechanisms.
Purpose of the Study:
- To investigate how replisomes bypass co-directional RNA polymerase (RNAP) obstacles during DNA replication.
- To identify factors and mechanisms involved in resolving RNAP-DNA replication conflicts.
Main Methods:
- The study likely involved in vitro biochemical assays and possibly in vivo genetic experiments to observe replisome-RNAP interactions.
- Analysis of DNA replication dynamics in the presence of various transcription complexes and DNA structures.
Main Results:
- Replisomes primarily use mRNA transcripts as primers for bypassing short, single RNAP obstacles.
- Bypassing longer or more complex RNAP arrays requires de novo primer synthesis downstream of the RNAP.
- Factors such as Rep, Mfd, UvrD, and RNase H facilitate RNAP displacement and continuous leading-strand synthesis.
- R-loops present similar challenges to RNAP arrays of equivalent length.
Conclusions:
- Replisome bypass of co-directional RNAPs is a multi-faceted process dependent on obstacle complexity and transcript length.
- Specific protein factors are crucial for resolving these replication-transcription conflicts, ensuring genome integrity.
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