title: Insect juvenile hormone binding protein shows ancestral fold present in human lipid-binding proteins.
abstract: Low molecular weight juvenile hormone binding proteins (JHBPs) are specific carriers of juvenile hormone (JH) in the hemolymph of butterflies and moths. As hormonal signal transmitters, these proteins exert a profound effect on insect development. The crystal structure of JHBP from Galleria mellonella shows an unusual fold consisting of a long alpha-helix wrapped in a highly curved antiparallel beta-sheet. JHBP structurally resembles the folding pattern found in tandem repeats in some mammalian lipid-binding proteins, with similar organization of one cavity and a disulfide bond between the long helix and the beta-sheet. JHBP reveals, therefore, an archetypal fold used by nature for hydrophobic ligand binding. The JHBP molecule possesses two hydrophobic cavities. Several lines of experimental evidence conclusively indicate that JHBP binds JH in only one cavity, close to the N- and C-termini, and that this binding induces a structural change. The second cavity, located at the opposite end of the molecule, could bind another ligand.
authors.affiliation: Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, 60-780 Poznan, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Kolodziejczyk
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bujacz
authors.forename: Michał
authors.initials: M
authors.lastname: Jakób
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ozyhar
authors.forename: Mariusz
authors.initials: M
authors.lastname: Jaskolski
authors.forename: Marian
authors.initials: M
authors.lastname: Kochman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D019476:Insect Proteins / Q000737:chemistry* / Q000378:metabolism; D007605:Juvenile Hormones / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism*; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D002352:Carrier Proteins; D019476:Insect Proteins; D007605:Juvenile Hormones; C035606:juvenile hormone-binding protein, insect