title: Molecular cloning and characterization of cDNAs for the gamma- and epsilon-subunits of mitochondrial F1F0 ATP synthase from the sweet potato.
abstract: Mitochondrial F1F0 ATP synthases purified from dicotyledonous plants contain six different subunits named alpha, beta, gamma, delta, delta', and epsilon. Our previous N-terminal amino acid sequence analyses indicated that the gamma- and epsilon-subunits of the sweet potato mitochondrial F1 correspond to the gamma- and epsilon-subunits of animal mitochondrial F1, respectively (Kimura, T., Nakamura, K., Kajiura, H., Hattori, H., Nelson, N., and Asahi, T. (1989) J. Biol. Chem. 264, 3183-3186). A cDNA clone for the gamma-subunit of the sweet potato mitochondrial F1 was identified by oligonucleotide hybridization selection of a cDNA library, and a cDNA clone for the epsilon-subunit was isolated by reverse polymerase chain reaction and hybridization selection of a cDNA library by the polymerase chain reaction product. The 1.4-kilobase long cDNA for the gamma-subunit contained a 978-base pair open reading frame coding for a precursor for the gamma-subunit. The mature gamma-subunit is composed of 281 amino acids, and its sequence showed significantly higher similarities with the gamma-subunit of animal mitochondrial F1 and bacterial F1 compared with the gamma-subunit of chloroplast CF1 from plants. The precursor for the gamma-subunit contained N-terminal presequence of 45 amino acid residues. By contrast, the 0.46-kilobase long cDNA for the epsilon-subunit contained a coding sequence of 207-base pairs for the mature epsilon-subunit of 69 amino acid residues that is preceded by an ATG codon suggesting that the epsilon-subunit is synthesized without the cleavable presequence for mitochondrial import. The amino acid sequence of the epsilon-subunit of sweet potato mitochondrial F1 showed similarities of 25 and 36% amino acid positional identity with the epsilon-subunits of mitochondrial F1 from yeast and bovine, respectively.
authors.affiliation: Laboratory of Biochemistry, School of Agriculture, Nagoya University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Morikami
authors.forename: G
authors.initials: G
authors.lastname: Ehara
authors.forename: K
authors.initials: K
authors.lastname: Yuuki
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum
chemical_list: D004272:DNA, Mitochondrial; D011498:Protein Precursors; D006180:Proton-Translocating ATPases