Mechanism of ATP Synthase (F F ): Analysis at the level of amino acid residues of subunits.

大肠杆菌的ATP合酶与线粒体中的ATP合酶具有基本相同的结构和功能。该酶的催化部分<F_1>由、和5个亚基组成<alpha><beta><gamma><delta><epsilon>，具有ATP酶活性。该<F_o>部分具有三个亚基，a、B和c，并且作为质子通道起作用。这八个亚基由unc操纵子编码，其DNA序列已由本课题组测定。我们分离了150多个unc操纵子突变体，并建立了快速测定其氨基酸残基变化的方法。本研究在氨基酸残基水平上研究了该酶的作用机制和组装。(1)我们已经分析了催化协同酶使用抑制剂和突变体。结果表明，该酶的单中心催化和多中心催化两种机理可以很好地分离.突变研究表明，Arg-246或其附近的区域对于催化协同性是重要的。(2)组装突变（在<beta>和<gamma>亚基）进行了广泛的分析，并提出了一个新的模型的酶。(3)进行了亚基突变的广泛分析<F_o>。提出了残基参与质子传递系统的设想。

The ATP synthase of Escherichia coli has essentially the same structure and functions as those found in mitochondria. The catalytic portion of the enzyme, <F_1> , consists of 5 subunits <alpha> , <beta> , <gamma> , <delta> and <epsilon> , and has ATPase activity. The <F_o> portion has three subunits, a, b and c, and functions as a proton channel. The eight subunits are encoded by the unc operon which DNA sequence was determined by our group. We isolated more than 150 mutants of unc operon and established rapid method to determine their altered amino acid residues. In this research project we studied mechanism and assembly of the enzyme at the level of amino acid residues.(1) We have analyzed catalytic cooperativity of the enzyme using inhibitors and mutants. Our results showed that the two mechanisms uni- and multi- site catalyses of the enzyme can be clearly separated. Mutation studies indicated that Arg-246 or the region in its vicinity is important for the catalytic cooperativity.(2) Assembly mutations (in <beta> and <gamma> subunits) were analyzed extensively, and a new model for the enzyme was proposed.(3) Extensive analysis of mutations in <F_o> subunits was carried out. Residues participating proton relay system were proposed.