FIG 6.

Intracellular levels of c-di-GMP in V. cholerae expressing an empty vector or DGC VC1067, VC1372, or VC1376 quantified with LC-MS/MS. The intracellular c-di-GMP levels of strains expressing alleles containing mutations in the active site motif of each DGC were also quantified. The black bars indicate strains grown in LB medium, while the gray bars indicate strains grown in LB medium with SHB. Error bars indicate standard deviations. Brackets indicate statistical significance, which was determined using a Student one-tailed t test (n = 3, P < 0.05).