title: Mitochondrial ATPase subunit 6 and cytochrome B gene polymorphisms in young obese adults.
abstract: We hypothesized that the mutational strand asymmetry is more strongly exerted upon the mitochondrial cytochrome b (Cytb) gene, which is distant from the origin of the light-strand replication (Ori(L)), than upon the ATPase subunit 6 (ATP6) gene, which is close to the Ori(L). To test this hypothesis, we determined the sequences of these two genes in 96 Japanese young obese adults. The frequency of G-->A transitions was significantly higher than that of C-->T transitions in the Cytb gene, whereas the frequencies of G-->A and C-->T transitions were not significantly different in the ATP6 gene. The marked mutational strand asymmetry in the Cytb gene can be explained by the deamination of C to uracil in the long single-stranded state of the heavy strand during replication. The ratio of the nonsynonymous substitutions at the second codon positions to those at the first codon positions was significantly lower in the Cytb gene than in the ATP6 gene. The physicochemical differences between the standard and the replaced amino acid residues were significantly smaller in the Cytb gene than in ATP6 one. The present study indicates that amino acid sequences are less variable for Cytb than for ATP6 in spite of the strong mutational strand asymmetry for the Cytb gene.
authors.affiliation: Department of Sports Medicine, Research Center of Health, Physical Fitness and Sports, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Fuku
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Oshida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takeyasu
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Guo
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kurata
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Yamada
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Sato
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000328:Adult; D003573:Cytochrome b Group / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007564:Japan; D008928:Mitochondria / Q000201:enzymology; D025261:Mitochondrial Proton-Translocating ATPases; D008957:Models, Genetic; D009154:Mutation; D009765:Obesity / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D011110:Polymorphism, Genetic
chemical_list: D003573:Cytochrome b Group; D004272:DNA, Mitochondrial; C501005:MT-ATP6 protein, human; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases