title: Crystal structure of the neurophysin-oxytocin complex.
abstract: The first crystal structure of the pituitary hormone oxytocin complexed with its carrier protein neurophysin has been determined and refined to 3.0 A resolution. The hormone-binding site is located at the end of a 3(10)-helix and involves residues from both domains of each monomer. Hormone residues Tyr 2, which is buried deep in the binding pocket, and Cys 1 have been confirmed as the key residues involved in neurophysin-hormone recognition. We have compared the bound oxytocin observed in the neurophysin-oxytocin complex, the X-ray structures of unbound oxytocin analogues and the NMR-derived structure for bound oxytocin. We find that while our structure is in agreement with the previous crystallographic findings, it differs from the NMR result with regard to how Tyr 2 of the hormone is recognized by neurophysin.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Rose
authors.forename: C K
authors.initials: CK
authors.lastname: Wu
authors.forename: C D
authors.initials: CD
authors.lastname: Hsiao
authors.forename: E
authors.initials: E
authors.lastname: Breslow
authors.forename: B C
authors.initials: BC
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009481:Neurophysins / Q000737:chemistry*; D010121:Oxytocin / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary
chemical_list: D009481:Neurophysins; D010121:Oxytocin