Proteome fractions of genes involved in transcription. Relative proteome fractions of the core RNA polymerase subunits α (RpoA), β (RpoB), β′ (RpoC), δ (RpoE), ε (RpoY), and ω (YloH), as well as for the sigma factors σ^A (SigA), σ^B (SigB), σ^X (SigX), σ^H (SigH), σ^W (SigW), σ^L (SigL), σ^D (SigD), and σ^I (SigI) for the genome-reduced strains Δ6, PG10, and PS38. Note that the scales are different for the three panels.