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Updated: Sep 14, 2025
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Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
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Networked Salt-Bridges Mediate Magnesium-Dependent Conformational Dynamics and Functional Regulation in Type IA
Keir Neuman1, Yeonee Seol2, Yuk-Ching Tse-Dinh1
1Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
Research Square
|July 25, 2025
Summary
Magnesium ions regulate protein motion in Type IA topoisomerases by controlling salt-bridge networks. This discovery offers insights into enzyme function and the design of new drugs.
Area of Science:
- Biochemistry
- Structural Biology
- Enzymology
Background:
- Protein conformational dynamics are crucial for enzyme function.
- Mechanisms regulating these dynamics are not fully understood.
Purpose of the Study:
- To investigate the role of magnesium ions in regulating conformational transitions of Type IA topoisomerases.
- To elucidate the molecular mechanisms underlying enzyme regulation.
Main Methods:
- Molecular dynamics simulations
- Targeted protein mutagenesis
- Functional assays
Main Results:
- Identified a magnesium-binding site that controls the DNA gate in Type IA topoisomerases.
- Demonstrated that magnesium ions tune the kinetics of salt-bridge network switching.
- Showed magnesium's role in enzyme activity and protection against DNA damage.
Conclusions:
- A conserved network of salt-bridges, modulated by magnesium, regulates Type IA topoisomerase conformational dynamics.
- This provides a framework for understanding cation-dependent protein regulation.
- Findings enable rational design of cation-sensitive proteins and inhibitors.
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