FIG. 6.

Subcellular localization of Stk1-HA in S. aureus. Exponentially growing cultures of S. aureus strain ST1006 (8325-4 carrying the control vector pMK4-Pprot) (vec) or expressing the stk1-HA gene (strain ST1007) were fractionated into cytosolic (CYT), membrane (MB), cell wall (CW), and supernatant (SN) compartments and immunoblotted with a commercial anti-HA monoclonal antibody. The equivalent of 1 ml of culture was loaded in each well, and molecular mass standards (kDa) are indicated on the left. Equivalent loading was controlled by staining the nitrocellulose membrane with Ponceau red (bottom) before immunoblotting. The asterisk indicates the presence of the likely protein A band, and the arrowhead indicates the position of the Stk1 band.