摘要
The ε-subunit is the smallest subunit of chloroplast ATP synthase, and is known to inhibit ATPase activity in isolated CF1-ATPase. As a result ε is sometimes called an inhibitory subunit. In addition, and perhaps more importantly, the ε -subunit is essential for the coupling of proton translocation to ATP synthesis (as proton gate). The relation between the structure and function of ε -subunit of ATP synthase in higher plant chloroplast has been studied by molecular biological methods such as site-directed mu-tagenesis and truncations for C- or N-terminus of ε -subunit. The results showed that: (1) Thr42 of ε-subunit is important for its structure and function; (2) compared with the ε-subunit in E.coli, the ε-subunit of chloroplast ATP synthase is more sensitive to C- or N-terminus truncations.
ε亚基是叶绿体ATP合酶最小的一个亚基,有阻寒ATP合酶的质子通道和抑制其水解ATP活力的两种功能。用定点突变和缺失等分子生物学方法对ε亚基的结构功能进行了研究,结果表明:ε亚基42位上的苏氨酸(Thr42)对维持其结构和功能都很重要。与大肠杆菌ATP合酶相比,叶绿体ATP合酶ε亚基C端和N端的氨基酸残基缺失对其结构功能的影响更为敏感。
基金
国家重点基础研究发展规划项目(G1998010100)
国家自然科学基金(30170078)
