TABLE 2.
Catalytic and structural properties of kustc1061 from K. stuttgartiensis, characterized orthologues from B. anammoxidans, and anammox strain KSU1 and hydroxylamine oxidoreductase from N. europaea
Kinetic values are given for mammalian cytochrome c as electron acceptor. Reduced methyl viologen was used as electron donor for NO2− reduction. NR, not reported.
| Property | K. stuttgartiensis | B. anammoxidans | KSU-1 | N. europaea |
|---|---|---|---|---|
| Vmax NH2OH (μmol min−1 mg−1) | 4.8 | 21 | 9.6 | 28.5 |
| kcat NH2OH (s−1) | 15 | 64 | 19 | 95 |
| Km NH2OH (μm) | 4.4 | 26 | 33 | 3.6 |
| kcat/Km NH2OH (s−1 μm−1) | 3.4 | 2.5 | 0.57 | 26 |
| Vmax N2H4 (μmol min−1 mg−1) | 1.6 | 1.1 | 0.54 | 14 |
| kcat N2H4 (s−1) | 4.9 | 3.4 | 1.1 | 47 |
| Km N2H4 (μm) | 54 | 18 | 25 | 4 |
| kcat/Km N2H4 (s−1 μm−1) | 0.1 | 0.19 | 0.04 | 12 |
| NO2− reduction (μmol min−1 mg−1) | 0.18a | 0.87b | NR | 6.18c |
| Total size (kDa) | 184 | 183 | 118 | 200 |
| Subunit size (kDa) | 61.5 | 58 | 53 | 67 |
| Subunit composition | α3 | α3 | α2 | α3 |
| Catalytic heme optical maximum (nm) | 468 | 468 | 468 | 463 |
| References | This paper | 49 | 50 | 20, 51, 52 |
a Specific activity with 0.1 mm nitrite.
b Specific activity with 2.5 mm nitrite.
c Vmax.