A transcribing RNA polymerase molecule survives DNA replication without aborting its growing RNA chain

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• DNA replication and transcription are fundamental cellular processes.
• The potential for conflict between DNA replication and transcription machinery is a key area of research.
• Previous studies showed stalled RNA polymerase ternary complexes can be bypassed by replication forks.

Purpose of the Study:

• To investigate if the bypass of stalled transcription complexes by replication forks is a general phenomenon.
• To determine if actively transcribing RNA polymerases are also bypassed by replication forks.
• To generalize previous findings on transcription-replication fork interactions.

Main Methods:

• Creation and analysis of multiple Escherichia coli RNA polymerase ternary transcription complexes.
• Experimental manipulation of DNA replication fork passage over transcription complexes.
• Observation of RNA polymerase complex fate and RNA chain elongation post-bypass.

Main Results:

• Stalled Escherichia coli RNA polymerase ternary complexes remain on the DNA template after replication fork passage.
• Bypassed complexes retain their ability to resume RNA elongation.
• Actively transcribing RNA polymerases and various ternary complexes are also successfully bypassed by replication forks.

Conclusions:

• The ability of DNA replication forks to bypass transcription complexes is a general feature of Escherichia coli transcription.
• Transcription intermediates, whether stalled or actively elongating, can be effectively navigated by replication machinery.
• This finding has significant implications for understanding genome stability and gene expression during DNA replication.