Related Experiment Video
Updated: Aug 6, 2026
07:05
Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA
Published on: September 8, 2021
Electron microscopic observation and single-stranded DNA binding activity of the Mcm4,6,7 complex
1Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Tokyo, Machida, 194-8511, Japan.
Journal of Molecular Biology
|July 8, 2000
Summary
The Mcm4,6,7 complex functions as a DNA helicase essential for eukaryotic DNA replication. Its activity is regulated by Mcm2 and Mcm3,5 complexes, impacting DNA replication processes.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Mcm2-7 proteins are crucial for eukaryotic DNA replication.
- These proteins possess conserved DNA-dependent ATPase motifs.
- A 600 kDa human Mcm4,6,7 complex exhibits DNA helicase activity.
Purpose of the Study:
- To investigate the structural and functional properties of the human Mcm4,6,7 complex.
- To elucidate the role of Mcm2 and Mcm3,5 complexes in regulating Mcm4,6,7 helicase activity.
Main Methods:
- Electron microscopy with negative staining.
- Gel-shift assays to assess DNA binding affinity.
- Analysis of regulatory interactions with Mcm2 and Mcm3,5 complexes.
Main Results:
- The Mcm4,6,7 complex forms toroidal structures with a central channel and slit-like structures.
- DNA binding affinity is comparable to SV40 T antigen, requiring longer single-stranded DNA.
- Nucleoprotein complexes visualized as 'beads on a string'.
- Mcm2 and Mcm3,5 complexes inhibit Mcm4,6,7 helicase activity.
Conclusions:
- The Mcm4,6,7 complex functions as a DNA helicase.
- Formation of the 600 kDa complex is essential for its helicase activity.
- Regulation by Mcm2 and Mcm3,5 is critical for DNA replication control.
