Porter A C, Kumamoto C, Aldape K, Simoni R D
J Biol Chem. 1985 Jul 5;260(13):8182-7.
A plasmid that carries the uncF gene of Escherichia coli, which codes for the b subunit of the proton-translocating ATPase (F1F0), was mutagenized with hydroxylamine and ethyl methanesulfonate. Mutated plasmids were characterized by complementation analysis and by in vitro transcription/translation. Eleven of the plasmids mutated specifically in uncF were studied in detail: the nucleotide sequences of their uncF genes were determined and their effects on the F1F0 were measured. The results suggest that a C-terminal portion of the b subunit that involves the glycine residue at position 131, is required for the formation of a functional proton pore as well as for the binding of F1 to F0. A mutation in the N-terminal portion of the b subunit, in the glycine residue at position 9, also prevented the formation of a functional proton pore, but had only a small effect on the binding of F1 to F0.
携带大肠杆菌uncF基因（该基因编码质子转运ATP酶（F1F0）的b亚基）的质粒，用羟胺和甲磺酸乙酯进行诱变。通过互补分析和体外转录/翻译对突变质粒进行表征。对11个在uncF中特异性突变的质粒进行了详细研究：测定了它们uncF基因的核苷酸序列，并测量了它们对F1F0的影响。结果表明，b亚基涉及第131位甘氨酸残基的C末端部分，对于功能性质子孔的形成以及F1与F0的结合是必需的。b亚基N末端部分第9位甘氨酸残基的突变也阻止了功能性质子孔的形成，但对F1与F0的结合只有很小的影响。
