Table 2.
Molecular and enzymatic properties of Cu-containing nitrite reductase
| Subunit compositiona | Visible absorption peaksb (nm) | EPR | Physiological electron donor | Activityc | Ref. | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
|
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| T1 Cu | T2 Cu | Affinity constant for NO2− | Turnover | ||||||||
|
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| gII | AII (mT) | gII | AII (mT) | (μM) | (×103 s−1) | ||||||
| Class I | N. oceani | (38,000)×3 | 455, 575 | — | — | 2.237 | 19.4 | — | 52 | 1.600 | Present study |
| A. cycloclastes | (37,000)×3 | 464, 590 | 2.195 | 7.30 | 2.262 | 17.5 | pseudoazurin | 500 | 0.172 | (12, 16, 17, 20, 23) | |
| A. xylosoxidans | (36,500)×3 | 460, 593 | 2.208 | 6.30 | 2.298 | 14.2 | azurin, cytochrome c553 | 34 | 0.445 | (1, 9, 10, 24) | |
|
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| Class II | N. europaea | (40,100)×3 | 607 | 2.250 | 6.80 | 2.260 | 17.0 | cytochrome c552 | n.d. | 0.027 | (8) |
| N. gonorrheaed | (36,200)×3 | 458, 585 | n.d. | n.d. | n.d. | n.d. | azurin | n.d. | 0.290 | (6) | |
| H. marismortui | (34,100 or 35,800)×3 | 465, 600 | 2.232 | 4.40 | 2.304 | 13.3 | — | n.d. | 1.680 | (14) | |
| F. oxysporum | (41,800)×2 | 470, 595 | 2.220 | 6.82 | 2.320 | n.d. | azurin, cytochrome c549 | n.d. | 0.621 | (22) | |
a
Molecular weight was calculated based on the nucleotide sequence.
b
Maximum peaks are shown in bold.
c
An artificial electron donor (reduced methylviologen or phenazine methosulfate) was used as the electron donor except for the A. cycloclastes enzyme (pseudoazurin) and N. europaea enzyme (cytochrome c552).
d
Recombinant of the soluble domain.
n.d., not determined.