Shull G E, Lingrel J B
J Biol Chem. 1986 Dec 25;261(36):16788-91.
We have isolated cDNA clones for the rat stomach (H+ + K+)-ATPase by employing a novel procedure involving the use of oligonucleotides corresponding to conserved amino acid sequences of related cation transport ATPase and a cross-hybridization with the sheep kidney (Na+ + K+)-ATPase alpha-subunit cDNA. The complete nucleotide sequence of the cDNA has been determined and the amino acid sequence of the protein deduced. The ATPase consists of 1,033 amino acids and has an Mr of 114,012. Amino acid homology and hydropathy plot comparisons between the gastric ATPase and the (Na+ + K+)-ATPase catalytic subunit demonstrate a striking similarity which suggests that their higher order structure and mechanism of action are virtually identical. The greatest homology occurs in the phosphorylation site region and in domains which may be involved in nucleotide binding and energy transduction. The most substantial differences occur in the N-terminal region and in the transmembrane domains. In addition, we report the presence of an open reading frame 5' to the translation initiation site of the gastric ATPase, which raises the possibility that the mRNA is polycistronic.
我们采用了一种新方法，分离出了大鼠胃（H⁺ + K⁺）-ATP酶的cDNA克隆。该方法使用了与相关阳离子转运ATP酶保守氨基酸序列对应的寡核苷酸，并与绵羊肾（Na⁺ + K⁺）-ATP酶α亚基cDNA进行交叉杂交。已确定该cDNA的完整核苷酸序列，并推导了该蛋白质的氨基酸序列。该ATP酶由1033个氨基酸组成，分子量为114,012。胃ATP酶与（Na⁺ + K⁺）-ATP酶催化亚基之间的氨基酸同源性和亲水性图谱比较显示出惊人的相似性，这表明它们的高级结构和作用机制几乎相同。最大的同源性出现在磷酸化位点区域以及可能参与核苷酸结合和能量转导的结构域中。最显著的差异出现在N端区域和跨膜结构域中。此外，我们报告在胃ATP酶翻译起始位点5'端存在一个开放阅读框，这增加了该mRNA是多顺反子的可能性。
