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Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
Crystal structure of a ternary SAP-1/SRF/c-fos SRE DNA complex
Y Mo1, W Ho, K Johnston
1The Wistar Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Journal of Molecular Biology
|February 16, 2002
Summary
This study reveals the crystal structure of a ternary complex involving SAP-1, SRF, and c-fos DNA. It shows how these proteins interact to regulate gene activation, highlighting DNA bending and protein-DNA contact modulation.
Area of Science:
- Molecular Biology
- Structural Biology
- Genetics
Background:
- Combinatorial DNA binding regulates eukaryotic gene activation.
- The c-fos proto-oncogene promoter uses a serum response element (SRE).
- SRE mediates complex formation with Ets proteins (SAP-1/Elk-1) and SRF.
Purpose of the Study:
- Determine the crystal structure of a ternary SAP-1/SRF/c-fos SRE DNA complex.
- Elucidate the protein-DNA interactions and structural consequences.
- Compare this complex to related structures to understand regulatory mechanisms.
Main Methods:
- X-ray crystallography to determine the ternary complex structure.
- Analysis of protein-DNA contacts and DNA conformation.
- Comparative structural analysis with existing datasets.
Main Results:
- The crystal structure reveals SAP-1 monomer and SRF dimer on opposite DNA faces.
- SAP-1's DNA recognition helix contacts SRF's DNA recognition helix.
- The complex induces an 82-degree DNA bend and modulates protein-DNA interactions.
Conclusions:
- The SAP-1 B-box region may not significantly influence DNA recognition.
- DNA target sequence impacts protein cooperation in DNA recognition.
- Findings inform how SRF and Ets proteins modulate transcription factor binding for gene regulation.
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