Figure 4

The HD residues of VC1348 are required for in vivo function. The genes encoding wild type VC1348 and VC1348 with alanine substitutions in the HD motif (VC1348AA) were expressed ectopically in V. cholerae using an IPTG-inducible promoter. The EAL domain PDE VC1592 was included as a positive control. The motility of V. cholerae bearing expression plasmids or vector control was assayed in soft agar medium as an indication of c-di-GMP hydrolysis, which augments flagellar motility of V. cholerae. Each strain was inoculated into motility medium with (grey bars) or without (white bars) 0.5 mM IPTG. The diameter of each motility swarm was measured after 20 hours incubation at room temperature. Shown are the means and standard deviations for six biological replicates. ***P <0.001 by two-way ANOVA with Bonferroni’s post-test.