Western blot of cellular fractions. Staphylococci harbouring plasmids encoding C-terminally hexahistidine-tagged AgrB, Csm6 or Nh Cam1 were grown to an OD 600 of 0.5. Cells were disrupted to collect the total lysate fraction (L), which was subsequently fractionated by ultracentrifugation to obtain cytosolic (C) and membrane (M) fractions. Samples were blotted with a primary anti-His 6 antibody. Anti-RpoB was used as a loading control. The protein molecular weight ladder is shown in Supplementary Fig. 1b . The experiment was repeated for two biological replicates.
