Table 2.
Kinetic analyses of H. pyroli MsrAB, HpMsrA, HpMsrB domain, and its mutants.
| Form | Substrate |
Km (mM) |
kcat (min−1) |
kcat/Km (mM−1 min−1) |
|---|---|---|---|---|
| WT | Met-S-O | 0.17 ± 0.06 | 10.2 ± 1.3 | 60 ± 7 |
| Met-R-O | 0.05 ± 0.02 | 9.4 ± 0.4 | 188 ± 8 | |
| MsrA_D | Met-S-O | 0.25 ± 0.09 | 2.2 ± 0.3 | 8.8 ± 1.2 |
| MsrB_D | Met-R-O | 1.7 ± 0.1 | 4.8 ± 0.3 | 2.8 ± 0.2 |
| E193A | Met-S-O | 0.14 ± 0.06 | 6.5 ± 0.8 | 46 ± 6 |
| Met-R-O | 0.06 ± 0.02 | 4.7 ± 0.3 | 78 ± 5 | |
| D197A | Met-S-O | 0.15 ± 0.04 | 6.1 ± 0.9 | 41 ± 6 |
| Met-R-O | 0.06 ± 0.02 | 4.4 ± 0.3 | 73 ± 5 | |
| E193A/D197A | Met-S-O | 0.12 ± 0.05 | 5.7 ± 0.6 | 47 ± 5 |
| Met-R-O | 0.05 ± 0.02 | 3.0 ± 0.3 | 60 ± 6 | |
| E339A | Met-S-O | 0.04 ± 0.01 | 3.5 ± 0.1 | 88 ± 3 |
| Met-R-O | 0.02 ± 0.01 | 2.7 ± 0.4 | 135 ± 25 | |
| Y343F | Met-S-O | 0.12 ± 0.02 | 5.8 ± 0.2 | 48 ± 2 |
| Met-R-O | 0.03 ± 0.02 | 5.2 ± 0.7 | 173 ± 23 |
WT, wild-type MsrAB form; MsrA_D, MsrA domain form; MsrB_D, MsrB domain form.