Role of the b subunit of the Escherichia coli proton-translocating ATPase. A mutagenic analysis.
Role of the b subunit of the Escherichia coli proton-translocating ATPase. A mutagenic analysis.
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DOI：
10.1016/s0021-9258(17)39579-0
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发表时间：
1985-07
期刊：
影响因子：
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通讯作者：
A. Porter;Carol A. Kumamoto;K. Aldape;R. D. Simoni
中科院分区：
文献类型：
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作者：
A. Porter;Carol A. Kumamoto;K. Aldape;R. D. Simoni
用羟胺和甲磺酸乙酯诱变携带大肠杆菌uncF基因的质粒，该基因编码质子转运ATP酶（F1 F0）的B亚基。突变质粒的特征在于互补分析和体外转录/翻译。详细研究了11个在uncF中特异性突变的质粒：确定了它们的uncF基因的核苷酸序列，并测量了它们对F1 F0的影响。结果表明，C-末端部分的B亚基，涉及在位置131的甘氨酸残基，是必需的功能质子孔的形成，以及为F1到F0的结合。在N-末端部分的B亚基，在位置9的甘氨酸残基中的突变，也阻止了功能质子孔的形成，但只有一个小的影响F1到F0的结合。
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.