title: The NMR solution structure of subunit G (G(61)(-)(101)) of the eukaryotic V1VO ATPase from Saccharomyces cerevisiae.
abstract: Subunit G is an essential stalk subunit of the eukaryotic proton pump V(1)V(O) ATPase. Previously the structure of the N-terminal region, G(1)(-)(59), of the 13kDa subunit G was solved at higher resolution. Here solution NMR was performed to determine the structure of the recombinant C-terminal region (G(61)(-)(101)) of subunit G of the Saccharomyces cerevisiae V(1)V(O) ATPase. The protein forms an extended alpha-helix between residues 64 and 100, whereby the first five- and the last residues of G(61)(-)(101) are flexible. The surface charge distribution of G(61)(-)(101) reveals an amphiphilic character at the C-terminus due to positive and negative charge distribution at one side and a hydrophobic surface on the opposite side of the structure. The hydrophobic surface pattern is mainly formed by alanine residues. The alanine residues 72, 74 and 81 were exchanged by a single cysteine in the entire subunit G. Cysteines at positions 72 and 81 showed disulfide formation. In contrast, no crosslink could be formed for the mutant Ala74Cys. Together with the recently determined NMR solution structure of G(1)(-)(59), the presented solution structure of G(61)(-)(101) enabled us to present a first structural model of the entire subunit G of the S. cerevisiae V(1)V(O) ATPase.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
authors.forename: Sankaranarayanan
authors.initials: S
authors.lastname: Rishikesan
authors.forename: Malathy S S
authors.initials: MS
authors.lastname: Manimekalai
authors.forename: Gerhard
authors.initials: G
authors.lastname: Grüber
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005057:Eukaryotic Cells / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D012996:Solutions; C485339:VMA10 protein, S cerevisiae; D025262:Vacuolar Proton-Translocating ATPases; D003545:Cysteine