Schmid S L, Braell W A, Rothman J E
J Biol Chem. 1985 Aug 25;260(18):10057-62.
ATP facilitates the sequestration of displaced triskelions by uncoating protein. In so doing, ATP is not hydrolyzed; nor does the concentration of ATP affect the equilibrium of this binding. However, the rates of both the binding of uncoating protein to clathrin and of their dissociation are greatly accelerated by ATP. These properties suggest that ATP acts catalytically to speed the capture of displaced triskelions by uncoating protein, as well as stoichiometrically in its hydrolysis to drive the displacement of triskelions from cages. The nucleotide specificity of this "catalytic" site for ATP on the uncoating protein is much less strict than that of the distinct "hydrolytic" site that drives the ATP-dependent displacement of triskelions from cages.
ATP通过脱衣被蛋白促进移位三脚蛋白复合体的隔离。在此过程中,ATP不会被水解;ATP的浓度也不会影响这种结合的平衡。然而,脱衣被蛋白与网格蛋白的结合和解离速率都因ATP而大大加快。这些特性表明,ATP起到催化作用,加速脱衣被蛋白捕获移位的三脚蛋白复合体,同时在其水解过程中按化学计量比驱动三脚蛋白复合体从笼状结构中移位。脱衣被蛋白上这个ATP“催化”位点的核苷酸特异性远不如驱动ATP依赖的三脚蛋白复合体从笼状结构中移位的独特“水解”位点严格。