TABLE 2.
Kinetic parameters of the wild-type AlsS (B. subtilis) and the variants for acetolactate synthase and decarboxylase activitya
| Amino acid at residue 487 | Pyruvate
|
KIV
|
||||
|---|---|---|---|---|---|---|
| Km (mM) | kcat (s−1) | kcat/Km ratio | Km (mM) | kcat (s−1) | kcat/Km ratio | |
| Q | 13.6 ± 0.8 | 121 ± 13 | 8.9 ± 1.1 | 300 ± 35 | 8.9 ± 1.2 | 0.03 ± 0.005 |
| A | 8.7 ± 0.5 | 58 ± 8 | 6.7 ± 1.0 | 186 ± 27 | 1.1 ± 0.5 | 0.006 ± 0.003 |
| G | 1.6 ± 0.4 | 11 ± 5 | 6.9 ± 3.6 | 175 ± 18 | 0.8 ± 0.2 | 0.005 ± 0.001 |
| S | 1.1 ± 0.6 | 11 ± 6 | 10 ± 7.7 | 154 ± 21 | 0.8 ± 0.3 | 0.005 ± 0.002 |
| L | ND | ND | ND | 342 ± 45 | 5.4 ± 0.9 | 0.02 ± 0.003 |
| I | ND | ND | ND | 323 ± 26 | 4.8 ± 0.5 | 0.01 ± 0.002 |
a
The values shown after the ± signs are standard deviations. ND, not detectable.