The delta'-subunit of higher plant six-subunit mitochondrial F1-ATPase is homologous to the delta-subunit of animal mitochondrial F1-ATPase.
Mitochondrial F1-ATPases purified from several dicotyledonous plants contain six different subunits of alpha, beta, gamma, delta, delta' and epsilon. Previous N-terminal amino acid sequence analyses indicated that the gamma-, delta-, and epsilon-subunits of the sweet potato mitochondrial F1 correspond to the gamma-subunit, the oligomycin sensitivity-conferring protein and the epsilon-subunit of animal mitochondrial F1F0 complex (Kimura, T., Nakamura, K., Kajiura, H., Hattori, H., Nelson, N., and Asahi, T. (1989) J. Biol. Chem. 264, 3183-3186). However, the N-terminal amino acid sequence of the delta'-subunit did not show any obvious homologies with known protein sequences. A cDNA clone for the delta'-subunit of the sweet potato mitochondrial F1 was identified by oligonucleotide-hybridization selection of a cDNA library. The 1.0-kilobase-long cDNA contained a 600-base pair open reading frame coding for a precursor for the delta'-subunit. The precursor for the delta'-subunit contained N-terminal presequence of 21-amino acid residues. The mature delta'-subunit is composed of 179 amino acids and its sequence showed similarities of about 31-36% amino acid positional identity with the delta-subunit of animal and fungal mitochondrial F1 and about 18-25% with the epsilon-subunit of bacterial F1 and chloroplast CF1. The sweet potato delta'-subunit contains N-terminal sequence of about 45-amino acid residues that is absent in other related subunits. It is concluded that the six-subunit plant mitochondrial F1 contains the subunit that is homologous to the oligomycin sensitivity-conferring protein as one of the component in addition to five subunits that are homologous to subunits of animal mitochondrial F1.
Laboratory of Biochemistry, School of Agriculture, Nagoya University, Japan.
A
A
Morikami
K
K
Aiso
T
T
Asahi
K
K
Nakamura
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D004247:DNA / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010944:Plants / Q000201:enzymology; D011061:Poly A / Q000235:genetics; D014176:Protein Biosynthesis; D006180:Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D004247:DNA; D006180:Proton-Translocating ATPases