Fig 1.

RFHR 2-D gel electrophoresis of ribosomal proteins prepared from deletion mutants of the ribosomal protein genes. Ribosomal proteins (750 μg) were prepared from cells in the early exponential phase (OD₆₀₀ of ∼0.2) of the wild type (wt) (A), ΔrplO (L15) mutant (B), or ΔrplV (L22) mutant (C), grown in LB medium at 37°C and were used for RFHR two-dimensional gel electrophoresis as described in Materials and Methods. The areas of the two-dimensional gels that contained the spots of the L15 and L22 or L32 and L35 proteins were extracted from the gel images. Arrows indicate each ribosomal protein spot (A). Circles with dotted lines indicate protein spots that have disappeared (B and C). The deletion of rplO and rplV was confirmed by the disappearance of spots that correspond to L15 and L22, respectively. Significant reductions in the amount of L35 and L32 proteins were observed in the ribosomes prepared from the ΔrplO (L15) and ΔrplV (L22) mutants, respectively.