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Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
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Primer-Free Aptamer Selection Using A Random DNA Library
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Microbial Primer: Bacterial DNA supercoiling.

Charles J Dorman1

  • 1Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin D02 PN40, Ireland.

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|February 13, 2026
PubMed
Summary
This summary is machine-generated.

Bacterial DNA topology, maintained by supercoiling and strand separation, is managed by topoisomerase enzymes. Understanding DNA topology is crucial for bacterial pathogenesis and cellular processes like transcription and replication.

Keywords:
DNA supercoilingDNA topoisomerasestranscriptiontwin supercoiling domain model

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Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Bacterial DNA exists in an underwound state.
  • DNA responds to underwinding via supercoiling or single-stranded bubble formation.
  • DNA topology significantly impacts cellular functions.

Purpose of the Study:

  • To summarize key DNA topological features in bacteria.
  • To describe topoisomerase enzymes involved in managing DNA topology.
  • To discuss the interplay between DNA topology, transcription, replication, metabolism, and pathogenesis.

Main Methods:

  • Literature review and synthesis of existing research.
  • Explanation of DNA supercoiling and topoisomerase functions.
  • Discussion of topological influences on gene expression and DNA replication.

Main Results:

  • DNA topology is a critical factor in bacterial physiology.
  • Topoisomerase enzymes are essential for regulating DNA structure.
  • Changes in DNA topology affect bacterial pathogenesis.

Conclusions:

  • Bacterial DNA topology is a dynamic feature influenced by cellular processes.
  • Topoisomerases are key targets for therapeutic intervention.
  • Understanding DNA topology provides insights into bacterial survival and virulence.