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Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
Crystal structure of the yeast MATalpha2/MCM1/DNA ternary complex
1ETH-Zurich, Institut für Molekularbiologie und Biophysik, Switzerland.
Nature
|March 7, 1998
Summary
Researchers elucidated the structural basis of cooperative DNA binding between MATalpha2 and MCM1 transcription factors. This reveals novel protein-protein interactions and a unique
Area of Science:
- Molecular biology
- Structural biology
- Biochemistry
Background:
- MATalpha2 is a homeodomain repressor protein.
- MCM1 is a MADS-box transcription factor.
- Both proteins are involved in gene regulation.
Purpose of the Study:
- To determine the crystal structure of the MATalpha2-MCM1-DNA complex.
- To elucidate the protein-protein interactions mediating cooperative DNA binding.
- To understand the role of DNA bending in complex formation.
Main Methods:
- X-ray crystallography at 2.25 A resolution.
- Structural analysis of protein-protein and protein-DNA interactions.
Main Results:
- The structure reveals specific interactions between MATalpha2 and MCM1.
- MATalpha2's N-terminal extension forms a beta-hairpin interacting with MCM1.
- MCM1 induces DNA bending, facilitating protein complexation.
- An eight-amino-acid 'chameleon' sequence in MATalpha2 adopts different conformations (alpha-helix or beta-strand).
Conclusions:
- The determined structure provides insights into cooperative DNA binding mechanisms.
- The beta-hairpin interaction and DNA bending are crucial for complex stability.
- The 'chameleon' sequence may play a role in operator site recognition.
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