title: Crystal structure of the yeast vacuolar ATPase heterotrimeric EGC(head) peripheral stalk complex.
abstract: Vacuolar ATPases (V-ATPases) are multisubunit rotary motor proton pumps that function to acidify subcellular organelles in all eukaryotic organisms. V-ATPase is regulated by a unique mechanism that involves reversible dissociation into V₁-ATPase and V₀ proton channel, a process that involves breaking of protein interactions mediated by subunit C, the cytoplasmic domain of subunit "a" and three "peripheral stalks," each made of a heterodimer of E and G subunits. Here, we present crystal structures of a yeast V-ATPase heterotrimeric complex composed of EG heterodimer and the head domain of subunit C (C(head)). The structures show EG heterodimer folded in a noncanonical coiled coil that is stabilized at its N-terminal ends by binding to C(head). The coiled coil is disrupted by a bulge of partially unfolded secondary structure in subunit G and we speculate that this unique feature in the eukaryotic V-ATPase peripheral stalk may play an important role in enzyme structure and regulation by reversible dissociation.
authors.affiliation: Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Oot
authors.forename: Li-Shar
authors.initials: LS
authors.lastname: Huang
authors.forename: Edward A
authors.initials: EA
authors.lastname: Berry
authors.forename: Stephan
authors.initials: S
authors.lastname: Wilkens
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D019281:Dimerization; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D025262:Vacuolar Proton-Translocating ATPases