TABLE 1.
Kinetic constants of ScMVD, putPtMVD, PMD from H. volcanii and R. castenholzii, and M3K from T. acidophiluma
| Enzyme | Reference(s) | Activity (U · mg−1) | Km (μM)b | Km(ATP) (μM) | kcat (s−1) | kcat/Km (s−1 · μM−1)b |
|---|---|---|---|---|---|---|
| P. torridus putMVD | 3 ± 0.1 | 131 ± 18 (MVA) | 23 ± 0.1 | 1.9 | 1.5 × 10−2 (MVA) | |
| S. cerevisiae MVD | This study | 7 ± 0.7 | 133 ± 28 (MVAPP) | 61 ± 6 | 5.4 | 4 × 10−2 (MVAPP) |
| S. cerevisiae MVD | 39, 40 | 6.4 ± 0.2 | 123 ± 22 (MVAPP) | 61 ± 6 | 4.9 | 4 × 10−2 (MVAPP) |
| H. volcanii PMD | 44 | 5.6 ± 0.1 | 159 ± 15 (MVA-5P) | 289 ± 15 | 3.5 | 2.2 × 10−2 (MVA-5P) |
| R. castenholzii PMD | 45 | NA | 152 ± 38 (MVA-5P) | NA | 1.7 | 1.1 × 10−2 (MVA-5P) |
| T. acidophilum M3K | 31 | NA | 97 ± 6 (MVA) | NA | 5.0 | 5.1 × 10−2 (MVA) |
a
Activity values refer to the rate of ADP formation coupled to NADH oxidation. Values for putPtMVD and ScMVD are calculated from enzyme assays at 30°C in 50 mM Tris-HCl buffer, pH 7.5, with the addition of 10 mM MgCl2, 20 mM KCl, and 10 μg of pure putPtMVD or ScMVD. Assays were done in triplicate, and the means ± standard errors of the means for the kinetic constants are shown. Previous data for ScMVD, H. volcanii PMD, R. castenholzii PMD, and T. acidophilum M3K are taken from the literature. NA, not available.
b
Values are given for the respective substrate (in parentheses) of each enzyme (MVAPP, MVA-5P, or MVA).