大肠杆菌的F1F0 - ATP合酶。c亚基第29位的甘氨酸被缬氨酸取代影响功能但不影响组装。

The F1F0-ATPase of Escherichia coli. The substitution of glycine by valine at position 29 in the c-subunit affects function but not assembly.

作者信息

Fimmel A L, Norris U

机构信息

Department of Biochemistry, Faculty of Science, Australian National University, Canberra.

出版信息

Biochim Biophys Acta. 1989 Nov 27;986(2):257-62. doi: 10.1016/0005-2736(89)90475-6.

DOI:10.1016/0005-2736(89)90475-6

PMID:2556183

Abstract

Site-directed mutagenesis has been used to construct two mutations within the uncE gene, coding for the c-subunit of the F1F0-ATPase, resulting in the substitution of Gly-29 by Val and Gly-18 by Leu. The strain carrying the Gly-29----Val substitution is unable to grow on succinate as sole carbon source and possesses an uncoupled growth yield, while the strain carrying the Gly-18----Leu substitution possesses a wild-type phenotype. Membranes prepared from the strain carrying the Gly-29----Val substitution possess low levels of ATPase activity and are proton-impermeable. The F1-ATPase activity of this strain was found to be inhibited by approx. 75% when bound to the membrane. These results are discussed in relation to a previously proposed model for the F0 (Cox, G.B., Fimmel, A.L., Gibson, F. and Hatch, L. (1986) Biochim. Biophys. Acta 849, 62-69).

摘要

定点诱变已用于在uncE基因内构建两个突变，该基因编码F1F0 - ATP酶的c亚基，导致第29位甘氨酸被缬氨酸取代，第18位甘氨酸被亮氨酸取代。携带第29位甘氨酸突变为缬氨酸的菌株无法在琥珀酸盐作为唯一碳源的培养基上生长，且具有解偶联的生长产量，而携带第18位甘氨酸突变为亮氨酸的菌株具有野生型表型。由携带第29位甘氨酸突变为缬氨酸的菌株制备的膜具有低水平的ATP酶活性，且对质子不可渗透。该菌株的F1 - ATP酶活性在与膜结合时被发现受到约75%的抑制。结合之前提出的F0模型（考克斯，G.B.，菲默尔，A.L.，吉布森，F.和哈奇，L.（1986年）《生物化学与生物物理学报》849，62 - 69）对这些结果进行了讨论。