title: [Effect of point substitutions of Asp-714 and Asp-720 residues on the structure and function of the H+ -ATPase of the yeast plasma membrane].
abstract: Membrane-spanning M5 and M6 segments, which play a role in the formation of cation transport sites in H(+)-, Ca2(+)-, K(+)-, Na(+)-, and other P2-ATPases, are connected by a short extracytoplasmic loop. In the yeast plasma membrane H(+)-ATPase, which belongs to a family of P2-ATPases, the loop is connected to M5 and M6 through the Asp-714 and Asp-720 residues. In this work, the effect of point amino, acidreplacements of Asp-714 and Asp-720 by Ala, Val, Asn, and Glu residues on the function of the enzyme was studied. The Asp714Asn point mutant possessed activities similar to those of the wild-type enzyme, whereas the replacement of Asp-714 by other amino acid residues disrupted biogenesis and led to a loss of activity. All mutants with substitution of Asp-720 were expressed and possessed relatively high activity. The D720V mutant displayed significantly reduced expression levels, activity, H+ transport, and ATP hydrolyzing activity. Thus, substitutions of Asp-714, except for the D714N mutant, led to significant defects in biogenesis and/or function of the enzyme. The results indicate the important role for the Asp-714 residue in biogenesis, structure stability, and enzyme function.
authors.forename: V V
authors.initials: VV
authors.lastname: Petrov
authors.forename: R I
authors.initials: RI
authors.lastname: Ibragimov
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001224:Aspartic Acid / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000201:enzymology; D015870:Gene Expression; D006868:Hydrolysis; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D001224:Aspartic Acid; D000255:Adenosine Triphosphate; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases