Fig. 5: The lack of free 5S rRNA results in assembly defects.

a Cold sensitivity of cells expressing 23S-cp5S ribosomes. Exponentially-growing cultures of wt or DH42* cells were serially diluted and spotted onto LB/agar plates supplemented with Amp. Plates were incubated at 37 °C for 24 h or at 30 °C for 48 h. b Sucrose gradient analysis of ribosomal fractions isolated from wt or 23S-cp5S DH42* cells. Fractions shaded with dark (70S) and light (unassociated 50S subunits) gray boxes were collected for subsequent analysis. c Protein composition of the large subunits in wt (blue bars) or mutant (red bars) 70S ribosomes and of the unassociated mutant 50S subunits (purple bars). Red asterisks indicate the r-proteins that are significantly underrepresented (<60% of the remaining amount) in the unassociated 50S subunits. The bar graph represents the mean of two biological replicates with individual data points indicated by black dots. Raw data can be found in the Source Data file. d Relative location of the 5S rRNA (red) and underrepresented proteins (purple) in the large subunit structure viewed from the solvent side.