title: Isolation and in silico functional analysis of MtATP6, a 6-kDa subunit of mitochondrial F₁F0-ATP synthase, in response to abiotic stress.
abstract: Mitochondrial F(1)F(0)-ATP  synthase is a key enzymatic complex of energy metabolism that provides ATP for  the cell. Subunits of this enzyme over-express under stress conditions. Little  is known about the structure and regulatory mechanism of the F(0) portion of this enzyme. We isolated the full-length  coding sequence of the RMtATP6 gene from rice and wheat, and partial  sequences from Aegilops crassa and Triticum monococcum (Poaceae).  We found that the sequence of rice RMtATP6 is 1965 bp long and contains  two exons and one intron in 3'-UTR. Then, we analyzed the 2000-bp upstream  region of the initiation codon ATG of the RMtATP6 and AtMtATP6,  as promoter. The RMtATP6 coding sequence was found to be much conserved  in the different plant species, possibly because of its key role under stress  conditions. Promoter analysis demonstrated that RMtATP6 and AtMtATP6 include cis-acting elements such as ABRE, MYC/MYB, GT element in the upstream  region, which respond to abscisic acid stress hormone and might show vital its  roles in biotic and abiotic tolerance as an early-stress responsive gene. A  mitochondrial signal peptide of 30 amino acids in length and an N-terminal  cleavage site between amino acids 20 and 21 were discovered in RMtATP6.  In addition, we found a transmembrane domain with an alpha helix structure that  possibly passed through the mitochondrial inner membrane and established the  6-kDa subunit in the F(0) portion  of the enzyme complex. Apparently, under stress conditions, with increasing ATP  consumption by the cell, the 6-kDa subunit accumulates; by switching on F(1)F(0)-ATP  synthase it provides additional energy needed for cell homeostasis.
authors.affiliation: Institute of Biotechnology, Shiraz University, Shiraz, Iran.
authors.forename: A A
authors.initials: AA
authors.lastname: Moghadam
authors.forename: S M
authors.initials: SM
authors.lastname: Taghavi
authors.forename: A
authors.initials: A
authors.lastname: Niazi
authors.forename: M
authors.initials: M
authors.lastname: Djavaheri
authors.forename: E
authors.initials: E
authors.lastname: Ebrahimie
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D019295:Computational Biology / Q000379:methods*; D018076:DNA, Complementary / Q000302:isolation & purification; D004579:Electron Transport; D004587:Electrophoresis, Agar Gel; D005091:Exons / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D007438:Introns / Q000235:genetics; D007492:Iran; D008928:Mitochondria / Q000201:enzymology*; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012275:Oryza / Q000201:enzymology / Q000235:genetics; D006109:Poaceae / Q000201:enzymology; D011401:Promoter Regions, Genetic / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000201:enzymology / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D021122:Protein Subunits; D014157:Transcription Factors; C474451:F1F0-ATP synthase; D025261:Mitochondrial Proton-Translocating ATPases