ATPase activity of liposome-reconstituted Pdr11p and Aus1p. Purified Pdr11p and Aus1p were reconstituted into different liposomes (containing Rho-PE as fluorescent lipid marker) and assayed for ATPase activity using [ γ - 32 P] ATP. A: SDS PAGE analysis of a flotation assay of Pdr11p proteoliposomes in a sucrose gradient. Detection of lipids and protein in the same low density fraction validated successful reconstitution. Proteins are visualised by silver staining and lipids by fluorescence from Rho-PE. B: Relative ATPase activity of Pdr11p reconstituted in PS liposomes in presence of the indicated inhibitors: orthovanadate, 1 mM; BeSO 4 , 1 mM; NaF, 5 mM. Data is based on at least two reconstitutions from one purification batch. C: Lipid effect on ATPase activity of reconstituted Pdr11p and Aus1p. All activities are corrected for protein amount in the proteoliposomes. Data is based on two reconstitutions from one purification batch of each protein. PC, PC only; PS, PC/PS (1:1); PG, PC/PG (7:3).