Table 2.
Summary of kinetic parameters for GMKs, see also Figure S2
| Species | kcat (sec−1)a | Km (μM)a | Ki (μM)b | Modec | Phylum/Class |
|---|---|---|---|---|---|
| B. anthracis | 57.6 ± 21.9 | 78.1 ± 39.7 | 42.5 ± 7.3 | Comp | Firmicutes |
| B. subtilis | 23.0 ± 1.0 | 24.6 ± 3.4 | 13.5 ± 2.1 | Comp | Firmicutes |
| E. faecalis-1 | 37.3 ± 4.0 | 80.3 ± 14.3 | 5.1 ± 0.5 | Comp | Firmicutes |
| E. faecalis-2 | 23.4 ± 0.6 | 42.3 ± 3.2 | 355.0 ± 26.0 | Noncomp | Firmicutes |
| L. monocytogenes | 54.9 ± 5.6 | 84.7 ± 14.2 | 12.0 ± 1.1 | Comp | Firmicutes |
| S. aureus | 72.9 ± 7.2 | 35.1 ± 7.1 | 8.2 ± 0.4/7.0 ± 0.9 | Comp | Firmicutes |
| S. mutans | 68.9 ± 24.8 | 147.4 ± 68.6 | 16.6 ± 2.4 | Comp | Firmicutes |
| A. tumefaciens | 24.8 ± 0.5 | 18.0 ± 2.1 | 53.5 ± 8.9 | Comp | α-Proteobacteria |
| S. meliloti | 19.5 ± 0.3 | 14.1 ± 1.3 | 81.6 ± 11.8 | Comp | α-Proteobacteria |
| D. radiodurans | 44.5 ± 4.4 | 17.8 ± 5.4 | 1.6 ± 0.4 | Comp | Deinococcus-Thermus |
| T. thermophilus | 4.8 ± 0.4 | 17.5 ± 4.1 | 2.9 ± 0.5 | Comp | Deinococcus-Thermus |
| C. gilvus | 25.0 ± 2.7 | 22.5 ± 7.3 | 1.7 ± 0.5 | Comp | Actinobacteria |
| S. coelicolor | 25.5 ± 0.7 | 29.7 ± 3.4 | 61.5 ± 9.6 | Comp | Actinobacteria |
a
Values are kcat and Km for GMP with 4 mM ATP at 25 °C and were determined by globally fitting the kinetic data into the modified competitive inhibition equation (Supplemental Experimental Procedures).
b
Values are Ki for pppGpp. For S. aureus GMK, reported here are Ki for ppGpp and pppGpp, respectively.
c
Mode of inhibition was determined relative to GMP. Comp and noncomp stand for competitive and noncompetitive, respectively.