An Assay for Detecting RNA Topoisomerase Activity

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Type IA topoisomerases are enzymes involved in managing nucleic acid topology.
• Recent findings indicate RNA topoisomerase activity in various Type IA DNA topoisomerases.
• This dual activity suggests a broader role in solving topological problems for both DNA and RNA.

Purpose of the Study:

• To describe a detailed assay for detecting RNA topoisomerase activity.
• To evaluate RNA topoisomerase activity in a wide range of Type IA topoisomerases.
• To provide a comprehensive guide including strategy, procedures, troubleshooting, and limitations.

Main Methods:

• Development and validation of a specific biochemical assay.
• Testing the assay on diverse Type IA topoisomerases from bacteria, archaea, and eukarya.
• Systematic analysis of enzyme activity on RNA substrates.

Main Results:

• The assay successfully detected RNA topoisomerase activity in many, but not all, tested Type IA topoisomerases.
• Confirmation of RNA topoisomerase activity across different domains of life.
• Identification of enzymes with dual DNA and RNA topological activities.

Conclusions:

• Type IA topoisomerases possess significant RNA topoisomerase activity, expanding their known functions.
• The described assay is a valuable tool for further research into nucleic acid topology.
• These enzymes play a crucial role in managing topological stress in both DNA and RNA molecules.