Immunoanalysis of DnaK in native 50S and 30S ribosomal subunits. (Lane 1) Control, DnaK (30 ng ≅ 0.5 pmole); (lane 2) 5.2 A260 units ≅ 375 pmole of 30S subunits from strain CAN20-12E (dnaK+); (lane 3) 4.4 A260 units ≅ 160 pmole of 50S subunits from strain CAN20-12E; (lane 4) 5.6 A260 units of 30S subunits from strain BB11 (ΔdnaK); (lane 5) 5.6 A260 units of 50S subunits from strain BB11 (ΔdnaK). The subunits were boiled in SDS sample buffer before subjecting them to an SDS-gel electrophoresis followed by the blotting procedure. The relative density of the bands was determined by scanning (Molecular Dynamics) and processing with the ImageQuant program. The pixel numbers for lanes 1, 2, and 3 were 63,840, 2434, and 21,577, yielding a molar ratio of DnaK per 30S and 50S subunits of 1:20,000 and 1:950, respectively. For details, see Materials and Methods.
