Maggio M B, Parsonage D, Senior A E
Department of Biochemistry, University of Rochester Medical Center, New York 14642.
J Biol Chem. 1988 Apr 5;263(10):4619-23.
The mutation Gly-29----Asp in the alpha-subunit of the F1-ATPase from Escherichia coli was characterized and shown to cause the following effects. 1) Oxidative phosphorylation was markedly impaired in vivo 2) Membrane ATPase and ATP-driven proton-pumping activities were decreased markedly. 3) Membranes were proton-permeable, and membrane-bound ATPase was dicyclohexylcarbodiimide-insensitive. Therefore, it appeared that integration between F1 and F0 was abnormal. This was confirmed directly by the demonstration that the mutant F1 bound poorly to stripped membranes from a normal strain. Purified, soluble mutant F1 had normal ATPase activity. These results suggest that residue Gly-29, which is strongly conserved in alpha-subunits of F1-ATPases, lies in a region of the alpha-subunit important for membrane binding. Thus, three regions of the F1-alpha-subunit have now been recognized, specialized for membrane binding, nucleotide binding, and alpha/beta intersubunit signal transmission, respectively. The approximate locations of the three regions are described.
对来自大肠杆菌的F1 - ATP酶α亚基中Gly - 29突变为Asp的情况进行了表征，并显示其会产生以下影响。1）体内氧化磷酸化明显受损。2）膜ATP酶和ATP驱动的质子泵活性显著降低。3）膜对质子具有通透性，且膜结合的ATP酶对二环己基碳二亚胺不敏感。因此，似乎F1和F0之间的整合异常。通过证明突变型F1与正常菌株的剥离膜结合不佳，直接证实了这一点。纯化的可溶性突变型F1具有正常的ATP酶活性。这些结果表明，在F1 - ATP酶α亚基中高度保守的Gly - 29残基位于α亚基中对膜结合很重要的区域。因此，现在已经识别出F1 - α亚基的三个区域，分别专门用于膜结合、核苷酸结合以及α/β亚基间信号传递。描述了这三个区域的大致位置。
