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DNA bending due to specific p53 and p53 core domain-DNA interactions visualized by electron microscopy
D I Cherny1, G Striker, V Subramaniam
1Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, D-37077, Germany. dtcherny@mpc186.mpibpc.gwdg.de
Journal of Molecular Biology
|December 10, 1999
Summary
The human tumor suppressor protein p53 and its core domain bend DNA upon binding. The p53 core domain plays a key role in this DNA bending, showing similar complexes to full-length p53.
Area of Science:
- Molecular Biology
- Biophysics
- Structural Biology
Background:
- The tumor suppressor protein p53 plays a critical role in cellular responses to DNA damage.
- Understanding the interaction of p53 with DNA is crucial for comprehending its function.
Purpose of the Study:
- To analyze the DNA bending induced by full-length human p53 and its core domain (p53CD).
- To investigate the specificity and extent of DNA bending upon protein-DNA complex formation.
Main Methods:
- Transmission electron microscopy (TEM) was employed to visualize and quantify DNA bending.
- Quantitative analysis using folded Gaussian distributions was performed on p53/DNA complexes.
Main Results:
- Both full-length p53 and p53CD specifically bind to the p53 consensus DNA sequence (p53CON).
- DNA bending angles induced by p53 ranged from 40-48 degrees, dependent on salt concentration.
- p53CD induced DNA bending of 35-37 degrees, with less variation across salt concentrations.
- Complex formation did not significantly alter DNA contour length.
Conclusions:
- The p53 core domain is critical for specific DNA binding and bending.
- Complexes formed by p53 and p53CD are similar under moderate salt conditions.
- Protein segments flanking the p53CD influence complex formation and DNA bending.