passages.id: split_5_test_1371_passage
passages.type: progene_text
passages.text: IscU and its iron - sulfur complex ( IscU - Fe / S ) stimulated the basal steady - state ATPase activity of Hsc66 weakly in the absence of Hsc20 but , in the presence of Hsc20 , increased the ATPase activity up to 480 - fold .