1g2n
From Proteopedia
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CRYSTAL STRUCTURE OF THE LIGAND BINDING DOMAIN OF THE ULTRASPIRACLE PROTEIN USP, THE ORTHOLOG OF RXRS IN INSECTS
Overview
The major postembryonic developmental events happening in insect life, including molting and metamorphosis, are regulated and coordinated temporally by pulses of ecdysone. The biological activity of this steroid hormone is mediated by two nuclear receptors: the ecdysone receptor (EcR) and the Ultraspiracle protein (USP). The crystal structure of the ligand-binding domain from the lepidopteran Heliothis virescens USP reported here shows that the loop connecting helices H1 and H3 precludes the canonical agonist conformation. The key residues that stabilize this unique loop conformation are strictly conserved within the lepidopteran USP family. The presence of an unexpected bound ligand that drives an unusual antagonist conformation confirms the induced-fit mechanism accompanying the ligand binding. The ligand-binding pocket exhibits a retinoid X receptor-like anchoring part near a conserved arginine, which could interact with a USP ligand functional group. The structure of this receptor provides the template for designing inhibitors, which could be utilized as a novel type of environmentally safe insecticides.
About this Structure
1G2N is a Single protein structure of sequence from Heliothis virescens with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of the ligand-binding domain of the ultraspiracle protein USP, the ortholog of retinoid X receptors in insects., Billas IM, Moulinier L, Rochel N, Moras D, J Biol Chem. 2001 Mar 9;276(10):7465-74. Epub 2000 Oct 26. PMID:11053444
Page seeded by OCA on Thu Feb 21 12:45:26 2008
