Figure 4

Subcellular localisation of YsxC. The ribosome-containing fraction of S. aureus SH1000 was made by ultracentrifugation after cell breakage and removal of cellular debris. Lane: 1, pre-stained molecular mass markers; 2, supernatant after ultracentrifugation; 3, pellet resuspended in buffer, containing 0.5% (v/v) Triton X-100, equal to that of the original suspension; 4, supernatant after the ultracentrifugation step was repeated; 5, pellet resuspended in buffer containing 1 M ammonium chloride (NH₄Cl); 6, supernatant after further ultracentrifugation; 7, pellet resuspended in an equal amount of buffer containing 1 M NH₄Cl. Samples were resolved by 12% (w/v) SDS-PAGE and A) Coomassie Blue stained, or B) Western blotted with antibodies against YsxC. Each lane contains the equivalent of 1 ml of original culture.