FIG. 1.

Association of YajL with ribosomes. (A) Lysates from the wild-type strain were centrifuged for 150 min at 36,000 rpm in a SW41 rotor through 15 to 30% sucrose gradients in 10 mM Tris (pH 7.6), 10 mM magnesium acetate, and 50 mM ammonium chloride at 4°C. Ribosomes were detected by their absorbance at 260 nm and YajL by immunoblot analysis (fractions 5 to 29). Representative results are shown for three repeat experiments. (B) Sucrose gradient sedimentation profiles of extracts from the parental strain (filled circles) and from the yajL mutant (empty circles) after they were stressed with 1 mM hydrogen peroxide for 10 min. Ribosomal subunits were centrifuged for 4 h at 36,000 × g in the same conditions as described above. The distribution of YajL in fractions 17 to 30 from the parental strain was detected by immunoblot analysis.