1. Assembly of subunit d (Vma6p) and G (Vma10p) and the NMR solution structure of subunit G (G1–59) of the Saccharomyces cerevisiae V1VO ATPase
- Author
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Sankaranarayanan Rishikesan, Malathy Sony Subramanian Manimekalai, Yin Hoe Yau, Susana Geifman Shochat, Subramanian Vivekanandan, Shovanlal Gayen, Gerhard Grüber, and Youg Raj Thaker
- Subjects
Models, Molecular ,Vacuolar Proton-Translocating ATPases ,Magnetic Resonance Spectroscopy ,Saccharomyces cerevisiae Proteins ,Time Factors ,Protein subunit ,ATPase ,Molecular Sequence Data ,Saccharomyces cerevisiae ,Vma7p ,Biophysics ,Biochemistry ,Protein Structure, Secondary ,law.invention ,Hydrophobic effect ,Vma10p ,law ,Amphiphile ,Hydrolase ,Vacuolar-type ATPase ,Amino Acid Sequence ,biology ,Circular Dichroism ,Vma6p ,Titrimetry ,Subunit d ,Cell Biology ,Surface Plasmon Resonance ,biology.organism_classification ,Yeast ,Solutions ,Kinetics ,Protein Subunits ,Crystallography ,V1VO ATPase ,Subunit G ,Subunit E ,Recombinant DNA ,biology.protein ,Protein Binding - Abstract
Understanding the structural traits of subunit G is essential, as it is needed for V(1)V(O) assembly and function. Here solution NMR of the recombinant N- (G(1-59)) and C-terminal segment (G(61-114)) of subunit G, has been performed in the absence and presence of subunit d of the yeast V-ATPase. The data show that G does bind to subunit d via its N-terminal part, G(1-59) only. The residues of G(1-59) involved in d binding are Gly7 to Lys34. The structure of G(1-59) has been solved, revealing an alpha-helix between residues 10 and 56, whereby the first nine- and the last three residues of G(1-59) are flexible. The surface charge distribution of G(1-59) reveals an amphiphilic character at the N-terminus due to positive and negative charge distribution at one side and a hydrophobic surface on the opposite side of the structure. The C-terminus exhibits a strip of negative residues. The data imply that G(1-59)-d assembly is accomplished by hydrophobic interactions and salt-bridges of the polar residues. Based on the recently determined NMR structure of segment E(18-38) of subunit E of yeast V-ATPase and the presently solved structure of G(1-59), both proteins have been docked and binding epitopes have been analyzed.
- Published
- 2009