Maegawa Yuki, Morita Hazuki, Iyaguchi Daisuke, Yao Min, Watanabe Nobuhisa, Tanaka Isao
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Japan.
Acta Crystallogr D Biol Crystallogr. 2006 May;62(Pt 5):483-8. doi: 10.1107/S0907444906006329. Epub 2006 Apr 19.
H(+)-transporting ATP synthase is a multi-subunit enzyme involved in the production of ATP, which is an essential molecule for living organisms as a source of energy. Archaeal A-type ATPase (A-ATPase) is thought to act as a functional ATP synthase in archaea and is thought to have chimeric properties of F-ATPase and V-ATPase. Previous structural studies of F-ATPase indicated that the major nucleotide-binding subunits alpha and beta consist of three domains. The catalytic nucleotide-binding subunit A of V/A-ATPase contains an insertion of about 90 residues which is absent from the F(1)-ATPase beta subunit. Here, the first X-ray structure of the catalytic nucleotide-binding subunit A of an A(1)-ATPase is described, determined at 2.55 A resolution. A(1)-ATPase subunit A from Pyrococcus horikoshii consists of four domains. A novel domain, including part of the insertion, corresponds to the 'knob-like structure' observed in electron microscopy of A(1)-ATPase. Based on the structure, it is highly likely that this inserted domain is related to the peripheral stalk common to the A- and V-ATPases. The arrangement of this inserted domain suggests that this region plays an important role in A-ATPase as well as in V-ATPase.
H(+)转运ATP合酶是一种参与ATP生成的多亚基酶，ATP作为能量来源，是生物体必需的分子。古菌A 型ATP酶（A-ATP酶）被认为在古菌中作为功能性ATP合酶起作用，并且被认为具有F-ATP酶和V-ATP酶的嵌合特性。先前对F-ATP酶的结构研究表明，主要的核苷酸结合亚基α和β由三个结构域组成。V/A-ATP酶的催化核苷酸结合亚基A包含约90个残基的插入序列，而F(1)-ATP酶β亚基中没有该序列。在此，描述了A(1)-ATP酶催化核苷酸结合亚基A的首个X射线结构，分辨率为2.55 Å。来自嗜热栖热菌的A(1)-ATP酶亚基A由四个结构域组成。一个包括部分插入序列的新结构域对应于在A(1)-ATP酶电子显微镜观察中看到的“球状结构”。基于该结构，极有可能这个插入结构域与A-ATP酶和V-ATP酶共有的外周柄有关。该插入结构域的排列表明该区域在A-ATP酶和V-ATP酶中都起重要作用。
