EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
    1.8.3.1 | more |
the plant sulfite oxidase does not accept cyctochrome c as substrate |
Saraca indica |
? |
- |
? |
| 1.8.3.1 | more |
mechanism of oxidation of sulfite and radical generation by ferric cytochrome c (Fe3+ cyt c) in the absence and presence of H2O2, oxidation of sulfite by the Fe3+ cyt c increased with sulfite concentration, overview |
Homo sapiens |
? |
- |
? |
| 1.8.3.1 | more |
reduced sulfite oxidase catalyzes single-electron transfer at molybdenum domain to reduce nitrite to nitric oxide. At physiological concentrations of nitrite, sulfite oxidase functions as nitrite reductase in the presence of a one-electron donor, exhibiting redox coupling of substrate oxidation and nitrite reduction to form NO. With sulfite, the physiological substrate, sulfite oxidase only facilitates one turnover of nitrite reduction. Nitrite reduction occurs at the molybdenum center via coupled oxidation of Mo(IV) to Mo(V). Reaction rates of nitrite to NO decreased in the presence of a functional heme domain, mediated by steric and redox effects of this domain. Nitrite binds to and is reduced at the molybdenum site of mammalian sulfite oxidase, which may be allosterically regulated by heme and molybdenum domain interactions, and contributes to the mammalian nitrate-nitrite-NO signaling pathway in human fibroblasts. Using phenosafranine or sulfite as reducing substrate, the Mo-domain shows much faster nitrite reduction to NO than holo-sulfite oxidase, catalytic Mo(IV) to Mo(V) nitrite reduction cycle, overview |
Homo sapiens |
? |
- |
? |
| 1.8.3.1 | more |
regeneration of the enzyme includes two, one-electron intramolecular electron transfers (IET) from the molybdenum (Mo) to the heme Fe and two, one-electron intermolecular electron transfers from the Fe to external ferricytochrome c |
Homo sapiens |
? |
- |
? |
| 1.8.3.1 | more |
sulfite ligand docking study |
Solanum lycopersicum |
? |
- |
? |
| 1.8.3.1 | more |
sulfite ligand docking study |
Populus trichocarpa |
? |
- |
? |
| 1.8.3.1 | more |
sulfite ligand docking study |
Brachypodium distachyon |
? |
- |
? |
| 1.8.3.1 | more |
sulfite ligand docking study, arginine residues particularly Arg374 is crucial for SOX-sulfite binding and two other residues Arg51 and Arg103 are also implicated to be important for SOX-sulfite bindings in plants |
Arabidopsis thaliana |
? |
- |
? |
| 1.8.3.1 | more |
the sulfite oxidase catalyzes single-electron transfer at molybdenum domain to reduce nitrite to nitric oxide. The SO Moco binding domain has the ability to oxidize sulfite in the presence of artificial electron acceptors like ferricyanide. The two-electron oxidation of sulfite to sulfate occurs at the molybdenum site, which is reduced from Mo(VI) to Mo(IV), followed by intramolecular electron transfer to the cytb5 site, with cytochrome c serving as the terminal electron acceptor. The movement of domains between the Moco domain and the cytb5 domain facilitated by the flexible linker is essential for efficient electron transfer between the heme and the Moco |
Homo sapiens |
? |
- |
? |
| 1.8.3.1 | nitrite + ferricytochrome c |
the enzyme can oxidize sulfite, and direct the electrons to reducing nitrite, to yield nitric oxide in the mitochondria |
Homo sapiens |
nitric oxide + ferrocytochrome c |
- |
? |
