title: Three-dimensional structure of the FK506 binding protein/ascomycin complex in solution by heteronuclear three- and four-dimensional NMR.
abstract: A high-resolution three-dimensional solution structure of the FKBP/ascomycin complex has been determined using heteronuclear multidimensional nuclear magnetic resonance spectroscopy (NMR) and a distance geometry/simulated annealing protocol. A total of 43 structures of the complex, including 3 tightly bound water molecules, were obtained using 1958 experimental restraints consisting of 1724 nuclear Overhauser effect (NOE) derived distances, 66 chi 1 and 46 phi angular restraints, and 122 hydrogen bond restraints. The root mean square (rms) deviations between the 43 FKBP/ascomycin solution structures and the mean atomic coordinates were 0.43 +/- 0.08 A for the backbone heavy atoms and 0.80 +/- 0.08 A for all non-hydrogen atoms. Angular order parameters for the family of 43 conformations were calculated to determine dihedral convergence. Order parameters for phi, psi, and chi 1 angles exhibited mean values of 0.98, 0.97, and 0.95, respectively, while the mean of the chi 2 order parameter was 0.63. Comparisons were made between the FKBP/ascomycin complex and two NMR-derived solution structures of unbound FKBP and the X-ray crystal structure of an FKBP/FK506 complex. Differences were observed between the FKBP/ascomycin complex and uncomplexed FKBP for residues 33-45 and 78-92. In contrast, the NMR-derived solution structure of the FKBP/ascomycin complex and the X-ray crystal structure of the FKBP/FK506 complex were very similar. Differences between the two complexes were mainly observed in the conformations of some highly solvent exposed side chains.
authors.affiliation: Pharmaceutical Discovery Division, Abbott Laboratories, Abbott Park, Illinois 60064.
authors.forename: R P
authors.initials: RP
authors.lastname: Meadows
authors.forename: D G
authors.initials: DG
authors.lastname: Nettesheim
authors.forename: R X
authors.initials: RX
authors.lastname: Xu
authors.forename: E T
authors.initials: ET
authors.lastname: Olejniczak
authors.forename: A M
authors.initials: AM
authors.lastname: Petros
authors.forename: T F
authors.initials: TF
authors.lastname: Holzman
authors.forename: J
authors.initials: J
authors.lastname: Severin
authors.forename: E
authors.initials: E
authors.lastname: Gubbins
authors.forename: H
authors.initials: H
authors.lastname: Smith
authors.forename: S W
authors.initials: SW
authors.lastname: Fesik
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006860:Hydrogen Bonding; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012996:Solutions; D016559:Tacrolimus / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D022021:Tacrolimus Binding Proteins; D014867:Water / Q000737:chemistry
chemical_list: D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D008024:Ligands; D011994:Recombinant Proteins; D012996:Solutions; D014867:Water; C058028:immunomycin; D022021:Tacrolimus Binding Proteins; D016559:Tacrolimus