title: Evidence for major structural changes in subunit C of the vacuolar ATPase due to nucleotide binding.
abstract: The ability of subunit C of eukaryotic V-ATPases to bind ADP and ATP is demonstrated by photoaffinity labeling and fluorescence correlation spectroscopy (FCS). Quantitation of the photoaffinity and the FCS data indicate that the ATP-analogues bind more weakly to subunit C than the ADP-analogues. Site-directed mutagenesis and N-terminal sequencing of subunit C from Arabidopsis (VHA-C) and yeast (Vma5p) have been used to map the C-terminal region of subunit C as the nucleotide-binding site. Tryptophan fluorescence quenching and decreased susceptibility to tryptic digestion of subunit C after binding of different nucleotides provides evidence for structural changes in this subunit caused by nucleotide-binding.
authors.affiliation: Universität des Saarlandes, Fachrichtung 2.5, Biophysik, Universitätsbau 76, D-66421 Homburg, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Armbrüster
authors.forename: Christina
authors.initials: C
authors.lastname: Hohn
authors.forename: Anne
authors.initials: A
authors.lastname: Hermesdorf
authors.forename: Karin
authors.initials: K
authors.lastname: Schumacher
authors.forename: Michael
authors.initials: M
authors.lastname: Börsch
authors.forename: Gerhard
authors.initials: G
authors.lastname: Grüber
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D013050:Spectrometry, Fluorescence; D014357:Trypsin / Q000737:chemistry; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D029701:Saccharomyces cerevisiae Proteins; C447616:VMA5 protein, S cerevisiae; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D014357:Trypsin; D025262:Vacuolar Proton-Translocating ATPases