TABLE 3.
Properties of XR from various organisms
| Organism (reference[s]) | Subunit mol mass (kDa) | Native mol mass (kDa) | kcat (min−1)a | Km for xylose (mM)a | kcat/Km for xylose (mM−1 min−1)a | Km for NADPH (μM) | kcat/Km for NADPH (μM−1 min−1) | Km for NADH (μM) | Optimal pH |
|---|---|---|---|---|---|---|---|---|---|
| N. crassa (this work) | 38.4 | 53 | 3,600 | 34 | 106 | 1.8 | 2,000 | 16 | 5.5 |
| C. intermedia (21, 24) | 36 | 58 | 900 | 50 | 18 | 56 | 16 | 28 | 6.0 |
| C. parapsilosis (20) | 36.6 | 69 | 3,100b | 32b | 98b | 37 | 939b | 3.3 | 6.0 |
| C. tropicalis (33) | 36.5 | 58 | NDc | 30-37 | ND | 9-18 | ND | ND | 6.0 |
| C. tenuis (7, 23) | 36 | 60 | 1,300 | 72 | 18 | 4.8 | 271 | 25 | 6.0 |
| P. tannophilus (4) | 38 | 38 | 600 | 162 | 4 | 59 | 10 | ND | 7.0 |
| P. stipitus (30) | 34 | 65 | 1,500 | 42 | 36 | 9 | 167 | 21 | 6.0 |
| S. cerevisiae (11) | 33 | 33 | 860 | 13.6 | 63 | 7.6 | 113 | ND | ND |
a
With NADPH as a cofactor, except for C. parapsilosis.
b
With NADH as a cofactor.
c
ND, not determined.