Related Experiment Videos
Solution structure of the basic region from the transcriptional activator GCN4
V Saudek1, H S Pasley, T Gibson
1Merrell Dow Research Institute, Strasbourg, France.
Biochemistry
|February 5, 1991
Summary
The basic region of the GCN4 transcriptional activator is a flexible helix that becomes more stable at lower temperatures. DNA binding region structure is unaffected by leucine zipper dimerization.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- The transcriptional activator GCN4 plays a crucial role in gene regulation.
- Understanding the structure of its DNA-binding basic region is key to deciphering its function.
Purpose of the Study:
- To investigate the three-dimensional structure of the GCN4 basic region.
- To determine how the leucine zipper domain influences the basic region's structure.
- To explore the implications for DNA binding.
Main Methods:
- Synthesis of peptide fragments of GCN4 (residues 240-280 and 220-280).
- Nuclear magnetic resonance (NMR) spectroscopy.
- Circular dichroic (CD) spectroscopy.
Main Results:
- The GCN4 basic region, in isolation, exists as a flexible, loosely helical segment.
- Helical stability of the basic region is enhanced by trifluoroethanol and lower temperatures.
- Dimerization through the leucine zipper domain does not alter the basic region's structure.
Conclusions:
- The GCN4 basic region exhibits intrinsic flexibility.
- Structural integrity of the basic region is independent of leucine zipper-mediated dimerization.
- These findings provide insights into the mechanism of GCN4's sequence-specific DNA binding.