title: NMR studies of subunit c of the ATP synthase from Propionigenium modestum in dodecylsulphate micelles.
abstract: The structure of the Na+, Li+ or H+-binding c subunit of the ATP synthase from Propionigenium modestum was studied by NMR. Subunit c in dodecylsulphate micelles consists of four alpha-helical segments, I-IV, that are connected by short linker peptides with non-regular secondary structures. We propose that helices I (V4-I26) and IV (I69-V85) are membrane-spanning structures, and that helices II and III and the intervening hydrophilic loop are located in the cytoplasm. The Na+-binding residues Q32, E65 and S66 are located in the I-->II and III-->IV helix connections, probably near the membrane surface on the cytoplasmic side.
authors.affiliation: Mikrobiologisches Institut, Eidgenössische Technische Hochschule, Zürich, Switzerland.
authors.forename: U
authors.initials: U
authors.lastname: Matthey
authors.forename: G
authors.initials: G
authors.lastname: Kaim
authors.forename: D
authors.initials: D
authors.lastname: Braun
authors.forename: K
authors.initials: K
authors.lastname: Wüthrich
authors.forename: P
authors.initials: P
authors.lastname: Dimroth
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry; D008823:Micelles; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010316:Particle Size; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D008823:Micelles; D011994:Recombinant Proteins; D012967:Sodium Dodecyl Sulfate; D006180:Proton-Translocating ATPases