Extended Data Fig. 2: Levels of csm expression and Rcs pathway-related promoters.
a, Activity of the csm promoter was measured in strains containing a chromosomal LacZ reporter (Pcsm-lacZ) or no reporter controls (lacZ—controls) (n = 6 biologically independent samples). b, Expression of the csm promoter was partially restored in the igaA mutant background upon expression of igaA from a low copy number plasmid (pPF2143, RK2 origin; T5-lac promoter) versus control plasmid (pPF1622) (n = 5 biologically independent samples). MFI, median fluorescence intensity. c, Organization of a predicted capsular polysaccharide biosynthesis locus and predicted rcsA gene in Serratia. d, Expression levels of the rcsA promoter (PrcsA) is elevated in strains igaA and mdoG, which suggests positive autoregulation of rcsA upon Rcs-pathway induction (n = 5 biologically independent samples). e, Capsule locus expression, measured from a wza promoter fusion to eYFP (Pwza), was reduced in Rcs-activated strains igaA and mdoG. The decrease in capsule locus expression is consistent with TEM imaging which showed no evidence of capsule synthesis in the igaA mutant (n = 5 biologically independent samples). All bars shown are the mean and error bars represent the s.e.m. For panels d and e, two-sided t-tests were used to determine statistical significance. Detailed statistical testing can be found in the accompanying Source Data file. ****P < 0.0001; ***P < 0.001.
