酿酒酵母H(+)-ATP酶的Dio-9抗性pma1-1突变体的分子与生化特性

Molecular and biochemical characterization of the Dio-9-resistant pma1-1 mutation of the H(+)-ATPase from Saccharomyces cerevisiae.

作者信息

Van Dyck L, Petretski J H, Wolosker H, Rodrigues Júnior G, Schlesser A, Ghislain M, Goffeau A

机构信息

Unité de Biochimie Physiologique, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.

出版信息

Eur J Biochem. 1990 Dec 27;194(3):785-90. doi: 10.1111/j.1432-1033.1990.tb19470.x.

DOI:10.1111/j.1432-1033.1990.tb19470.x

PMID:2148517

Abstract

The plasma-membrane H(+)-ATPase gene PMA1 was sequenced in four Dio-9-resistant strains of Saccharomyces cerevisiae, isolated independently. The same amino acid substitution Ala608----Thr was found in the four mutated strains. The mutant ATPase activity was decreased while the Km value for MgATP was increased. The ATPase efficiency (V/Km) of the mutant was reduced by a factor of 25 under acid conditions (pH 5.5), and by a factor of 10 at physiological pH (pH 6.6). The mutation also strongly reduces the inhibition by vanadate of ATPase activity, suggesting that the altered amino acid is involved in phosphate binding and/or in the E1-E2 transition.

摘要

对独立分离得到的四株酿酒酵母Dio - 9抗性菌株的质膜H(+) - ATP酶基因PMA1进行了测序。在这四株突变菌株中发现了相同的氨基酸替换，即丙氨酸608突变为苏氨酸。突变型ATP酶活性降低，而MgATP的Km值增加。在酸性条件（pH 5.5）下，突变体的ATP酶效率（V/Km）降低了25倍，在生理pH（pH 6.6）下降低了10倍。该突变还强烈降低了钒酸盐对ATP酶活性的抑制作用，表明氨基酸的改变参与了磷酸盐结合和/或E1 - E2转变。