Fig. S4.

Bacterial growth and the abundance of 100S ribosomes at 37 °C in different genetic backgrounds. (A) Only the ΔsigB mutant was slightly attenuated in growth. Cell growth was measured by monitoring optical density (OD) at 600 nm. Error bars are SEs of three independent biological replicates. (B) Sucrose density gradient (5–25%) profiles of S. aureus JE2 and the ΔhflX mutant during early-log, midlog, and stationary phases. No significant difference in 100S abundance was observed between the wild-type (WT) and the ΔhflX null under these conditions. Each panel represents 2.5 Abs₂₆₀ units of RNA input. (C) Comparison of 100S abundance in the Δhpf, Δrsh, and ΔsigB null mutants. Ribosome profiles were analyzed as in B. HPF synthesis is greatly reduced in the ΔsigB mutant (Fig. 4B), thereby decreasing 70S dimerization.