3E8W

Crystal Structure of Epiphyas postvittana Takeout 1

Summary for 3E8W

• Entry DOI: 10.2210/pdb3e8w/pdb
• Related: 3E8T
• Descriptor: Takeout-like protein 1, Ubiquinone-8 (3 entities in total)
• Functional Keywords: takeout, epiphyas postvittana, transport protein
• Biological source: Epiphyas postvittana (Light brown apple moth)
• Total number of polymer chains: 1
• Total formula weight: 25239.48

Authors

Hamiaux, C.,Stanley, D.,Greenwood, D.R.,Baker, E.N.,Newcomb, R.D. (deposition date: 2008-08-20, release date: 2008-12-09, Last modification date: 2024-10-30)

Primary citation

Hamiaux, C.,Stanley, D.,Greenwood, D.R.,Baker, E.N.,Newcomb, R.D.
Crystal structure of Epiphyas postvittana takeout 1 with bound ubiquinone supports a role as ligand carriers for takeout proteins in insects
J.Biol.Chem., 284:3496-3503, 2009

PubMed Abstract: Takeout (To) proteins are found exclusively in insects and have been proposed to have important roles in various aspects of their physiology and behavior. Limited sequence similarity with juvenile hormone-binding proteins (JHBPs), which specifically bind and transport juvenile hormones in Lepidoptera, suggested a role for To proteins in binding hydrophobic ligands. We present the first crystal structure of a To protein, EpTo1 from the light brown apple moth Epiphyas postvittana, solved in-house by the single-wavelength anomalous diffraction technique using sulfur anomalous dispersion, and refined to 1.3 angstroms resolution. EpTo1 adopts the unusual alpha/beta-wrap fold, seen only for JHBP and several mammalian lipid carrier proteins, a scaffold tailored for the binding and/or transport of hydrophobic ligands. EpTo1 has a 45 angstroms long, purely hydrophobic, internal tunnel that extends for the full length of the protein and accommodates a bound ligand. The latter was shown by mass spectrometry to be ubiquinone-8 and is probably derived from Escherichia coli. The structure provides the first direct experimental evidence that To proteins are ligand carriers; gives insights into the nature of endogenous ligand(s) of EpTo1; shows, by comparison with JHBP, a basis for different ligand specificities; and suggests a mechanism for the binding/release of ligands.

PubMed: 19073605
DOI: 10.1074/jbc.M807467200

Experimental method

X-RAY DIFFRACTION (2.5 Å)