This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1hg4
From Proteopedia
Revision as of 09:36, 20 March 2008
| |||||||
| , resolution 2.4Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | , , , , and | ||||||
| Ligands: | |||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ULTRASPIRACLE LIGAND BINDING DOMAIN FROM DROSOPHILA MELANOGASTER
Overview
Ultraspiracle (USP) is the invertebrate homologue of the mammalian retinoid X receptor (RXR). RXR plays a uniquely important role in differentiation, development, and homeostasis through its ability to serve as a heterodimeric partner to many other nuclear receptors. RXR is able to influence the activity of its partner receptors through the action of the ligand 9-cis retinoic acid. In contrast to RXR, USP has no known high-affinity ligand and is thought to be a silent component in the heterodimeric complex with partner receptors such as the ecdysone receptor. Here we report the 2.4-A crystal structure of the USP ligand-binding domain. The structure shows that a conserved sequence motif found in dipteran and lepidopteran USPs, but not in mammalian RXRs, serves to lock USP in an inactive conformation. It also shows that USP has a large hydrophobic cavity, implying that there is almost certainly a natural ligand for USP. This cavity is larger than that seen previously for most other nuclear receptors. Intriguingly, this cavity has partial occupancy by a bound lipid, which is likely to resemble the natural ligand for USP.
About this Structure
1HG4 is a Single protein structure of sequence from Drosophila melanogaster. Full crystallographic information is available from OCA.
Reference
The structure of the ultraspiracle ligand-binding domain reveals a nuclear receptor locked in an inactive conformation., Clayton GM, Peak-Chew SY, Evans RM, Schwabe JW, Proc Natl Acad Sci U S A. 2001 Feb 13;98(4):1549-54. Epub 2001 Feb 6. PMID:11171988
Page seeded by OCA on Thu Mar 20 11:36:42 2008
