FIGURE 3.
Induction of the methylcitrate cycle-related genes and enzyme activity in M. smegmatis in response to different phosphate availabilities. (A) The transcriptional profiles of regX3 and methylcitrate-cycle-related genes when M. smegmatis was grown in MOPS-propionate (10 mM) medium without phosphate (P-) or with a high phosphate level (P+, 10 mM K2HPO4). RNA was collected at 12 h after incubation. Relative fold change was tested using 16S rRNA as housekeeping gene. The data of relative fold change under the high phosphate condition was set to 1.0 (arbitrary unit). (B) Comparison analysis of total MCS activity in M. smegmatis grown at the low- and high-phosphate level. Ten micrograms of total protein were used in the MCS activity assay. Data are presented as means ± SEM calculated from three independent experiments. Unpaired two-tailed Student’s t-test, *p < 0.05; **p < 0.01; and ***p < 0.001.