title: Heteronuclear 1H-15N nuclear magnetic resonance studies of the c subunit of the Escherichia coli F1F0 ATP synthase: assignment and secondary structure.
abstract: Nuclear magnetic resonance (NMR) studies of the c subunit of F1F0 ATP synthase from Escherichia coli are presented. A combination of homonuclear (1H-1H) and heteronuclear (1H-15N) 2D and 3D methods was applied to the 79-residue protein, dissolved in trifluoroethanol. Resonance assignment for all the backbone amide groups and many C alpha H side-chain protons was achieved. Analysis of inter- and intraresidue 1H-1H nuclear Overhauser effect (NOE) data and scalar coupling constant information indicates that this protein contains two extended regions of predominant alpha-helical character (residues 10-40 and 48-77) separated by an eight-residue segment which displays little evidence of ordered secondary structure. This model is consistent with information about the molecular motion of the protein deduced from 15N-1H heteronuclear NOE data and observed pKa values of carboxylic acid groups.
authors.affiliation: Department of Biochemistry, University of Oxford, U.K.
authors.forename: T J
authors.initials: TJ
authors.lastname: Norwood
authors.forename: D A
authors.initials: DA
authors.lastname: Crawford
authors.forename: M E
authors.initials: ME
authors.lastname: Steventon
authors.forename: P C
authors.initials: PC
authors.lastname: Driscoll
authors.forename: I D
authors.initials: ID
authors.lastname: Campbell
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000201:enzymology*; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D009587:Nitrogen Isotopes; D006859:Hydrogen; D006180:Proton-Translocating ATPases