Figure 7. RcsA is involved in CRP regulation of CPS expression.

(A) CPS levels of WT, ΔrcsA, Δcrp, and ΔcrpΔrcsA strains were determined. For complementation purposes, introduction of pRK415 and prcsA into ΔcrpΔrcsA strain were also determined. Bacterial strains were grown in LB broth as indicated at 37°C with agitation. After 16 h of growth, the bacterial glucuronic acid content was determined. *P<0.05 and **P<0.01 compared to the indicated group. (B) The β-galactosidase activities of K. pneumoniae CG43S3ΔlacZ and the isogenic strains (ΔlacZΔcrp, ΔlacZΔrcsA, and ΔlacZΔcrpΔrcsA) carrying the reporter plasmid pOrf12 (P_orf1-2::lacZ), pOrf315 (P_orf3-15::lacZ), or pOrf1617 (P_orf16-17::lacZ) were determined using log-phased cultures grown in LB medium. The results shown are an average from triplicate measurements in one single experiment representative of three independent experiments. Error bars indicate standard deviations. *P<0.05 compared to the indicated group.