Figure 6.

SV-associated translocase activity from a Dnf1,2,3-deficient mutant recognizes NBD-labeled PS and PE but not NBD-PC. SV-enriched membranes prepared from 38°C-shifted sec6-4Δdrs2Δdnf1,2,3 mutant cells expressing Drs2p from a multicopy (2μ) plasmid were labeled with NBD-lipids and incubated for 3 h at 25°C without ATP. The reaction was then split, ATP was added to one-half, and the incubation was continued an additional 2 h. At times indicated, the fraction of fluorescent lipid remaining in the cytosolic leaflet was determined as in the legend to Figure 2. Data shown are means ± SD of two independent experiments.