Harvested and resuspended in a lysis buffer containing 0.4 M sucrose, 50 mM 3-(Nmorpholino) propanesulfonic acid, pH 7.0, 10 mM NaCl, 5 mM EDTA, and 0.5 mM PMSF. Cells were broken using a bead beater, and centrifuged with 5,000 g for 30 min at 4 to remove glass beads and insoluble cell debris. The membrane and the soluble fractions were separated as previously described with slight modifications