Fig. 5

The activated conformation of Drs2p-Cdc50p. a Structural comparison of Drs2p-Cdc50p in the apo and active conformations. The yellow and purple boxes highlight the substrate-transporting path and the C-terminal helix switch in Drs2p. b A putative substrate-transporting path in Drs2p in the apo and active conformations. c–d The putative PI4P binding site of Drs2p in the apo and active conformations. The helix switch of Drs2p rotates by about 90° toward the right in going from the apo to the active conformation. e Complementation of drs2Δ cells (selected by G418) with plasmids carrying either wild-type DRS2 (WT), drs2-W1223A, drs2-K1227A, drs2-R1228A, drs2-Y1235A, drs2-H1236A, or an empty plasmid (drs2Δ). Cells were serially diluted and incubated at 30 and 20 °C for 2 days. f The ATPase activity of the wild-type Drs2p (WT) and mutant enzyme complexes preincubated with PI4P. Each triangle represents a data point. Error bars are standard deviations estimated from three independent measurements