TABLE 3.
Rates of CO- or H2-dependent reduction of Isf and Isf homologs catalyzed by cell extracts
| Protein | Cell extract | Rates of reduction with the following electron donors (nmol/min/mg of cell extract protein)a
|
|
|---|---|---|---|
| CO | H2 | ||
| Isf | M. thermophila | 20 ± 2 (0.37 ± 0.03) | 2.7 ± 0.5 (0.05 ± 0.01) |
| Af3 | A. fulgidus | 12 ± 2 (0.18 ± 0.03) | NDb |
| Cd1 | C. thermoaceticum | 6.2 ± 0.6 (0.11 ± 0.01) | ND |
| Mj2 | M. jannaschii | 1.2 ± 0.2 (0.024 ± 0.003) | 0.4 ± 0.1 (0.007 ± 0.001) |
a
Each value was determined from the slope of the linear portion of the time course. The values in parentheses are the changes in A480 per minute per milligram of cell extract protein. The values are means ± standard deviations based on three determinations.
b
ND, not detected (below the limit of detection, 0.1 nmol/min/mg of cell extract protein).