Fig 4.

YdiV affects motility independent of glucose at a step in flagellar biosynthesis downstream from CAP activation of flhDC. (A) Swimming motility diameter of wild-type E. coli CFT073 and the ΔydiV, ΔslyB, Δcrp, Δcya, ΔsdiA, ΔydiV ΔslyB, ΔydiV Δcrp, ΔydiV Δcya, and ΔydiV ΔsdiA mutants, cultured at 30°C in soft LB agar plates for 16 h. Data are averages of three independent experiments performed in triplicate. Error bars indicate standard errors of the means. Gray bars have a P value of <0.05 compared to the wild type as assessed by Student's t test. (B) Addition of excess glucose (0.8%) to motility agar decreases swimming motility in wild-type E. coli CFT073 and the Δcya mutant, but the ΔydiV, ΔsdiA, ΔydiV Δcya, and ΔydiV ΔsdiA strains are glucose insensitive. Data are averages of three independent experiments performed in triplicate. Error bars indicate standard errors of the means. *, P value < 0.05 as assessed by Student's t test.