Structure/Function of Recombinant Human Estrogen Receptor
Abstract
Interaction of the estrogen receptor with its ligands is mediated by a C-terminal region designated the hormone binding domain (HBD). We initiated structure-function studies in an attempt to improve our understanding of how estrogen activates the receptor and how antagonists inhibit its activity. We previously reported high yield expression of recombinant human estrogen receptor HBD and suggested that the isolated HBD forms dimers in solution and undergoes conformational changes comparable to those in the full-length protein. Small crystals of the HBD have been obtained, although these are not yet suitable for diffraction analysis. Structural modeling of the HBD predicts that the core of the HBD remains essentially unaffected by ligand binding. Fluorescence spectroscopy results also suggest that the HBD core is largely unaffected by ligand binding: all three of the HBD tryptophan residues appear to be located in hydrophobic environments in the presence and absence of ligand. Studies using iodide as a quenching agent showed that estradiol binding increased the accessibility of Trp36O, suggesting that ligand binding alters the conformational flexibility of the HBD. The modeling and fluorescence studies suggest that the major conformational changes induced by ligand binding may be confined to the N- and C-termini.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1999
- Accession Number
- ADA382977
Entities
People
- Larry E. Vickery
Organizations
- University of California, Irvine