Proton leakiness caused by cloned genes for the F0 sector of the proton-translocating ATPase of Escherichia coli: requirement for F1 genes.
Proton leakiness caused by cloned genes for the F0 sector of the proton-translocating ATPase of Escherichia coli: requirement for F1 genes.
复制标题
大肠杆菌质子转位 ATP 酶 F0 区段的克隆基因引起的质子泄漏：对 F1 基因的需求。
DOI：
10.1128/jb.169.11.4984-4990.1987
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发表时间：
1987
影响因子：
3.2
通讯作者：
Brusilow,WS
中科院分区：
文献类型：
--
作者：
Brusilow,WS
为了研究编码大肠杆菌质子转运ATP酶γ亚基的基因uncG的表达，在编码α亚基的基因uncA和uncG之间的基因间区域进行缺失。融合uncA和uncG的两个缺失编码α-γ融合多肽，其在体外和体内都合成良好，表明uncG表达通常由基因间区域中的核苷酸控制。携带这些融合基因和ATP酶其它亚基基因的多拷贝质粒对E.杆菌该效应被N，N '-二环己基碳二亚胺克服，表明细胞可能泄漏质子。通过在上游F0基因uncB中进行非极性缺失或通过将每个uncA-uncG融合基因克隆到从F0基因中去除的单独质粒上来消除有害作用，从而证明融合基因不是质子渗透性的主要原因。携带F0基因和δ亚基基因的质粒在unc+细胞中引起有害的质子泄漏，但在删除unc操纵子的细胞中不引起质子泄漏。因此，由这些不同质粒引起的质子泄漏是由于产生泄漏的F0质子通道，并且需要F1基因的存在。结果支持ATP酶组装模型，其中F1基因或多肽参与F0质子通道的形成或开放。
To study expression of uncG, the gene coding for the gamma subunit of the Escherichia coli proton-translocating ATPase, deletions were made in the intergenic region between uncA, the gene coding for the alpha subunit, and uncG. Two deletions which fused uncA and uncG coded for alpha-gamma fusion polypeptides which were synthesized well both in vitro and in vivo, demonstrating that uncG expression is normally controlled by nucleotides in the intergenic region. Multicopy plasmids carrying these fusion genes and the genes for the other subunits of the ATPase had a harmful effect on the growth of E. coli. The effect was overcome by N,N'-dicyclohexylcarbodiimide, indicating that the cells probably leaked protons. The deleterious effect was eliminated by making a nonpolar deletion in the upstream F0 gene uncB, or by cloning each of the uncA-uncG fusion genes onto a separate plasmid, removed from the F0 genes, thus demonstrating that the fusion genes were not primarily responsible for the proton permeability. A plasmid which carried F0 genes and the gene for the delta subunit caused deleterious proton leakiness in unc+ cells but not in cells from which the unc operon was deleted. The proton leakiness caused by these different plasmids was therefore due to the production of a leaky F0 proton channel and required the presence of F1 genes. The results support a model for ATPase assembly in which F1 genes or polypeptides are involved in the formation or opening of the F0 proton channel.