An unbroken network of interactions connecting flagellin domains is required for motility in viscous environments
Fig 5
Effects of FliC domain swaps between P. aeruginosa PAK and PAO1 strains on swimming motility and filament formation.
(A) Protofilament comparison of PAO1 (blue) and PAK (orange) strains. Outer domains in PAK are farther apart and do not engage in contacts. (B) Swimming motility and negative-stain EM images of the wild type PAO1 and PAK strains. (C) Swimming motility and negative-stain EM images of PAO1-ΔfliC strain complemented with PAK-FliC or FliC in which one or two domains are replaced with equivalent domains of PAK strain. (D) Comparison of average swimming speeds of P. aeruginosa strains in liquid media complemented with increasing concentration of Ficoll 400. Statistical significance for each condition is in S4 Table Blue bars represents the motile spread on semi-solid agar. Red bars represent average swimming speed in liquid medium (right vertical axis). Area of motile spread for each strain represents the average of ten replicates and it is normalized to that of the PAO1 wild type strain (A), or full-length wild type complemented strain (FliCWT) (B). Error bars represent standard deviation. Statistical significance was determined by Brown-Forsythe and Welch ANOVA test followed by a Dunnett’s T3 multiple comparison test for data series that passed Shapiro-Wilk normality test, or Kruskal-Wallis test for data series that did not passed normality test (ns—not significant; * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001).