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Author Spotlight: Investigating the Motion Dynamics of the Eukaryotic Replisome Components at the Single-Molecule Level
Published on: July 26, 2024
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DNA induces conformational changes in a recombinant human minichromosome maintenance complex
Emma L Hesketh1, Richard P Parker-Manuel1, Yuriy Chaban2
1From the Department of Biology, University of York, York YO10 5DD and.
The Journal of Biological Chemistry
|February 5, 2015
Summary
Researchers produced functional recombinant human MCM (minichromosome maintenance) complexes, demonstrating their ATP-dependent DNA unwinding and hydrolysis capabilities. This breakthrough enables in vitro studies of the human replicative helicase.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- DNA replication relies on the minichromosome maintenance (MCM) complex, a key component of the replicative helicase.
- While archaeal and yeast MCM complexes show DNA unwinding activity, higher eukaryotic MCM helicase activity is often studied within larger complexes.
- The human MCM complex's independent function and structure remained less characterized due to production challenges.
Purpose of the Study:
- To produce recombinant human MCM (hMCM) complex in Escherichia coli.
- To characterize the biochemical and structural properties of the recombinant hMCM complex.
- To assess the functional activity of hMCM in DNA unwinding and ATP hydrolysis.
Main Methods:
- Recombinant expression of the human MCM complex in E. coli.
- Biochemical assays to measure ATP hydrolysis and DNA unwinding activity.
- Single-particle asymmetric electron microscopy (EM) for structural analysis.
Main Results:
- Successfully produced functional recombinant hMCM complex lacking post-translational modifications.
- Demonstrated that recombinant hMCM exhibits ATP hydrolysis and duplex DNA unwinding capabilities.
- Structural analysis revealed that hMCM forms a hexamer and undergoes conformational changes upon DNA binding.
Conclusions:
- Recombinant hMCM is a functional hexameric DNA helicase.
- The produced hMCM complex serves as a valuable tool for in vitro biochemical reconstitution of the human replicative helicase.
- This work facilitates further mechanistic studies of human DNA replication initiation and elongation.
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