Figure 2.

Accumulation of ribosomal subunits assembly intermediates in the E. coli strains with inactivation of the 16S rRNA and 23S rRNA methyltransferase genes marked on the left side. WT corresponds to the parental isogeneic strain carrying all set of rRNA methyltransferase genes. Shown are sucrose gradient centrifugation profiles at subunit dissociation conditions (1 mM magnesium ions concentration) (A) and association conditions (10 mM magnesium ions concentration) (B). Left panels correspond to the cells grown at 37°C, while that to the right correspond to the cells grown at 20°C known to exacerbate ribosomal subunits assembly defects.