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Updated: Jul 11, 2025
09:26
DNA-Tethered RNA Polymerase for Programmable In vitro Transcription and Molecular Computation
Published on: December 29, 2021
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Structural Insight into Polymerase Mechanism via a Chiral Center Generated with a Single Selenium Atom
Tong Qin1, Bei Hu1, Qianwei Zhao1,2
1Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China.
International Journal of Molecular Sciences
|November 14, 2023
Summary
This study visualizes DNA synthesis stereochemistry using a selenium-modified probe, revealing an SN2 mechanism. Findings highlight the critical role of metal ions in DNA polymerase catalysis and drug design.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- DNA polymerase catalyzes DNA synthesis, a fundamental biological process.
- Phosphodiester bond formation involves phosphorus center inversion, crucial for DNA replication.
- Understanding DNA polymerase reaction mechanisms is key for developing therapeutics.
Purpose of the Study:
- To visualize the stereochemistry and catalysis of DNA synthesis.
- To provide explicit evidence for the in-line attacking SN2 mechanism in DNA polymerization.
- To investigate the impact of diastereomeric modifications on DNA polymerase binding and catalysis.
Main Methods:
- Utilized a single-selenium-atom-modified deoxyribonucleoside triphosphate (dNTP) probe.
- Captured pre- and post-reaction states to analyze stereochemical outcomes.
- Performed kinetic and thermodynamic studies to assess binding affinity and reaction selectivity.
Main Results:
- Visualized the center inversion and confirmed the SN2 mechanism of DNA polymerization.
- Determined the absolute configurations of diastereomers.
- Demonstrated that Mg2+ or Mn2+ ions significantly influence substrate binding and catalysis, with specific diastereomers being disruptive.
Conclusions:
- The study provides direct evidence for the stereochemical course of DNA polymerization.
- Highlights the critical role of the third metal ion in substrate recognition and phosphodiester bond formation.
- Offers insights for designing improved polymerase inhibitors and therapeutics.
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