title: The importance of the putative helices 4 and 5 of human vitamin D(3) receptor for conformation and ligand binding.
abstract: The 3-D structure of the human vitamin D(3) receptor has not been solved to date. To study the conformation of the ligand binding pocket and the amino acid residues important for binding of calcitriol and its synthetic 20-epi analog MC1288, we have introduced several point mutations into putative helices 4 and 5 of human vitamin D(3) receptor by site-directed mutagenesis. The amino acid residues Ser256, Glu257, Asp258, Gln259, Lys264, Ser265, Ser266, Glu269, Arg274, Ser278, and Phe279 were substituted by alanine. Our results suggest that Arg274 is important for the binding of calcitriol and probably also for the binding of the synthetic vitamin D analog MC1288, whereas Asp258, Gln259, Glu269, and Phe279 may have an important role in stabilizing the conformation of hVDR after ligand binding.
authors.affiliation: Department of Biochemistry, University of Kuopio, Kuopio, FIN-70211, Finland. vaisanen@messi.uku.fi
authors.forename: S
authors.initials: S
authors.lastname: Väisänen
authors.forename: C
authors.initials: C
authors.lastname: Duchier
authors.forename: J
authors.initials: J
authors.lastname: Rouvinen
authors.forename: P H
authors.initials: PH
authors.lastname: Mäenpää
mesh_terms: D000409:Alanine / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites; D002117:Calcitriol / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011487:Protein Conformation; D018167:Receptors, Calcitriol / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D008024:Ligands; D018167:Receptors, Calcitriol; D002117:Calcitriol; D000409:Alanine