Table 2. Inhibition of Exopolyphosphatase and ATPase activities by pppGpp and ppGpp.
| A | |||
| Protein | Exopolyphosphatase activities | ||
| Vmax (μM/min) | |||
| No (p)ppGpp | +1 mM pppGpp | +1 mM ppGpp | |
| (% decrease) | (% decrease) | ||
| MTB-PPX1 | 43.8±3.8 | 27.2±2.5 | 41.2±1.3 |
| (37.9±6.7%) | (5.9±0.7%) | ||
| EC-GPP | 115.2±12.5 | 81.2±3.8 | 108.3±3.4 |
| (29.5±4.4%) | (6.0±0.5%) | ||
| EC-PPX | 151.7±15.2 | 15.8±2.5 | 135.3±2.1 |
| (89.6±20.1%) | (10.8±1.2%) | ||
The maximum enzymatic reaction rates (Vmax values) calculated for assays performed in the presence of 1 mM pppGpp or ppGpp, were compared with the Vmax values obtained from analogous assays performed in the absence of (p)ppGpp. The percentage decrease in Vmax values are reported in parentheses. Vmax values are reported as the mean value (μM/min) ± S.D.