Fig 1.
Growth-phase-dependent expression of YknX and SdpC in B. subtilis cells. (A) Immunoblotting analysis of whole B. subtilis cells with various genetic backgrounds. Cells were grown in LB medium and collected at OD600s of 0.6 and 1.6. Total proteins (5 μg) were separated by 12% SDS-PAGE and analyzed by immunoblotting with polyclonal anti-YknX antibodies. Purified YknXHis (lane 1) was loaded as a positive control. A cross-reacting band with SDS-PAGE mobility slightly faster than that of YknX was more abundant in exponential- than in stationary-phase cells. (B) HB6098 (Pspac-sdpABC) cells were grown in the presence (+SdpC) and absence (-SdpC) of 1 mM IPTG to indicated ODs. A 10-μg volume of total protein was separated by 10% SDS-PAGE and probed with anti-YknX antibodies. N, cells grown overnight. (C) B. subtilis strains Cu1065 (WT), HB6127 (-YknWXYZ), and HB6182 (-SdpI and -YknWXYZ) were grown to indicated ODs. A 10-μg volume of total protein was separated by 16% SDS-PAGE and probed with anti-SdpC antibody. N, cells grown overnight.