1HG4

Ultraspiracle ligand binding domain from Drosophila melanogaster

Summary for 1HG4

• Entry DOI: 10.2210/pdb1hg4/pdb
• Descriptor: ULTRASPIRACLE, 2-(HEXADECANOYLOXY)-1-[(PHOSPHONOOXY)METHYL]ETHYL HEXADECANOATE (3 entities in total)
• Functional Keywords: nuclear hormone receptor, transcription factor, ligand binding
• Biological source: DROSOPHILA MELANOGASTER (FRUIT FLY)
• Cellular location: Nucleus: P20153
• Total number of polymer chains: 6
• Total formula weight: 192024.44

Authors

Schwabe, J.W.R.,Clayton, G.M. (deposition date: 2000-12-12, release date: 2001-02-23, Last modification date: 2023-12-13)

Primary citation

Clayton, G.M.,Peak-Chew, S.Y.,Evans, R.M.,Schwabe, J.W.R.
The Structure of the Ultraspiracle Ligand-Binding Domain Reveals a Nuclear Receptor Locked in an Inactive Conformation
Proc.Natl.Acad.Sci.USA, 98:1549-, 2001

PubMed Abstract: 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.

PubMed: 11171988
DOI: 10.1073/PNAS.041611298

Experimental method

X-RAY DIFFRACTION (2.4 Å)