title: Three-dimensional structure of the lipoyl domain from Bacillus stearothermophilus pyruvate dehydrogenase multienzyme complex.
abstract: The structure of the lipoyl domain from the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus has been determined by means of nuclear magnetic resonance spectroscopy. A total of 452 nuclear Overhauser effect distance constraints and 76 dihedral angle restraints were employed as the input for the structure calculations, which were performed using a hybrid distance geometry-simulated annealing strategy and the programs DISGEO and X-PLOR. The overall structure of the lipoyl domain (residues 1 to 79 of the dihydrolipoamide acetyltransferase polypeptide chain) is that of a flattened eight-stranded beta-barrel folded around a core of well-defined hydrophobic residues. The lipoylation site, lysine 42, is located in the middle of a beta-turn, and the N and C-terminal residues of the domain are close together in adjacent beta-strands at the opposite end of the molecule. The polypeptide backbone exhibits a 2-fold axis of quasi-symmetry, with the C alpha atoms of residues 15 to 39 and 52 to 76 being almost superimposable on those of residues 52 to 76 and 15 to 39, respectively (root-mean-square deviation = 1.48 A). The amino acid residues at key positions in the structure are conserved among all the reported primary structures of lipoyl domains, suggesting that the domains all fold in a similar way.
authors.affiliation: Laboratoire de Biochimie, URA 240 du CNRS, Ecole Polytechnique, Palaiseau, France.
authors.forename: F
authors.initials: F
authors.lastname: Dardel
authors.forename: A L
authors.initials: AL
authors.lastname: Davis
authors.forename: E D
authors.initials: ED
authors.lastname: Laue
authors.forename: R N
authors.initials: RN
authors.lastname: Perham
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003198:Computer Simulation; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D012996:Solutions
chemical_list: D011768:Pyruvate Dehydrogenase Complex; D012996:Solutions