1z5x

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spinqualitylabelsall models 1z5x, resolution 3.07Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

hemipteran ecdysone receptor ligand-binding domain complexed with ponasterone A

Overview

The ecdysone receptor is a hormone-dependent transcription factor that, plays a central role in regulating the expression of vast networks of, genes during development and reproduction in the phylum Arthropoda. The, functional receptor is a heterodimer of the two nuclear receptor proteins, ecdysone receptor (EcR) and ultraspiracle protein. The receptor is the, target of the environmentally friendly bisacylhydrazine insecticides, which are effective against Lepidoptera but not against Hemiptera or, several other insect orders. Here we present evidence indicating that much, of the selectivity of the bisacylhydrazine insecticides can be studied at, the level of their binding to purified ecdysone receptor ligand-binding, domain (LBD) heterodimers. We report the crystal structure of the ecdysone, receptor LBD heterodimer of the hemipteran Bemisia tabaci (Bt, sweet, potato whitefly) in complex with the ecdysone analogue ponasterone A., Although comparison with the corresponding known LBD structure from the, lepidopteran Heliothis virescens (Hv) ecdysone receptor revealed the, overall mode of ponasterone A binding to be very similar in the two cases, we observed that the BtEcR ecdysteroid-binding pocket is structured, differently to that of HvEcR in those parts that are not in contact with, ponasterone A. We suggest that these differences in the ligand-binding, pocket may provide a molecular basis for the taxonomic order selectivity, of bisacylhydrazine insecticides.

About this Structure

1Z5X is a Protein complex structure of sequences from Bemisia tabaci with PO4 and P1A as ligands. Full crystallographic information is available from OCA.

Reference

The X-ray structure of a hemipteran ecdysone receptor ligand-binding domain: comparison with a lepidopteran ecdysone receptor ligand-binding domain and implications for insecticide design., Carmichael JA, Lawrence MC, Graham LD, Pilling PA, Epa VC, Noyce L, Lovrecz G, Winkler DA, Pawlak-Skrzecz A, Eaton RE, Hannan GN, Hill RJ, J Biol Chem. 2005 Jun 10;280(23):22258-69. Epub 2005 Apr 4. PMID:15809296

Page seeded by OCA on Sun Nov 25 04:44:57 2007