title: Cloning of the yeast ATP3 gene coding for the gamma-subunit of F1 and characterization of atp3 mutants.
abstract: Saccharomyces cerevisiae pet mutants, of complementation group G115, are deficient in mitochondrial ATPase and have properties indicative of defective F1. In this study we show that C287/LU1, a mutant belonging to group G115, is complemented by the yeast nuclear ATP3 gene coding for the gamma-subunit of the mitochondrial F1-ATPase. The amino-terminal sequence of the mature gamma-subunit matches the sequence encoded by ATP3 starting with the 34th amino acid confirming the identity of the gene, and earlier evidence indicating that this F1 component is synthesized as a precursor with a long amino-terminal extension. The properties of the mitochondrial ATPase have been studied in C287/LU1 with an Ala273-->Val substitution in the carboxyl-terminal region of the gamma-subunit and in W303 delta ATP3, a mutant lacking the gamma-subunit as a result of a deletion in ATP3. Both strains have negligible ATPase activity but near normal concentrations of the alpha- and beta-subunits of F1. In W303 delta ATP3, the subunits do not form a stable F1 oligomer nor are they firmly associated with F0. This is not true of C287/LU1, which was found to assemble an F1-F0 complex. These data indicate that the yeast gamma-subunit has dual functions, one in catalysis of ATP hydrolysis/synthesis and the second in assembly/stability of F1.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York 10027.
authors.forename: M F
authors.initials: MF
authors.lastname: Paul
authors.forename: S
authors.initials: S
authors.lastname: Ackerman
authors.forename: J
authors.initials: J
authors.lastname: Yue
authors.forename: G
authors.initials: G
authors.lastname: Arselin
authors.forename: J
authors.initials: J
authors.lastname: Velours
authors.forename: A
authors.initials: A
authors.lastname: Tzagolof
authors.forename: S ]
authors.initials: S]
authors.lastname: Ackermann S [corrected to Ackerman
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D013329:Structure-Activity Relationship
chemical_list: D006180:Proton-Translocating ATPases