TABLE 2.
Activity of PHB cycling enzymes in extracts of succinate-grown M. extorquens AM1 wild-type and mutants.
| Enzyme | Activity (nmol/min/mg of
protein)a
|
||||
|---|---|---|---|---|---|
| AM1 | PhaA− | PhaB− | Cro− | Hbd− | |
| β-Ketothiolase | 392 | 0 | 400 | NT | NT |
| Acetoacetyl-CoA reductase | |||||
| NADH-dependent | 17 | 12 | 11 | NT | NT |
| NADPH-dependent | 13 | 10 | 0 | NT | NT |
| l-(+)-Crotonase | 25 | NT | NT | 17 | NT |
| NAD-dependent β-hydroxybutyrate dehydrogenase | 9 | NT | NT | NT | 0 |
a
Values are the average of three to four determinations; the range was ±10%. AM1, wild-type M. extorquens AM1; 0, not detectable; NT, not tested.