Fig. 3. Inner membrane localization of the 4′-phosphatase and the PtdIns-dependent phosphotransferase of R. leguminosarum.
The inner and outer membranes of strain CE3 were separated by isopycnic sucrose density gradient centrifugation, and ~0.4-ml fractions were collected. NADH oxidase and phospholipase A activities were assayed to locate inner and outer membrane fragments, respectively. A, NADH oxidase and phospholipase A activities in each fraction are expressed as a percentage of the total activity across the entire gradient. B, the 4′-phosphatase and the phosphotransferase activities were assayed in each fraction.