EC Number |
Substrates |
Organism |
Products |
Reversibility |
---|
1.8.99.5 | more |
no substrates: S3O62-, S2O32-. Methyl viologen is as effective as ferredoxin in coupling the sulfite reductase with hydrogenase while benzyl viologen is only 16% as effective as ferredoxin. No activity is observed with NAD, NADP, FAD or FMN. Varying the substrate concentration [SO 2-] from 1 to 2.5 micromol affects the stoichiometry of the enzyme reaction by alteration of the ratio of H2 uptake to S2- formed from 2.5:1 to 3.1:1 |
Clostridium pasteurianum |
? |
- |
? |
1.8.99.5 | more |
two-state hypothesis for enzyme activity: an active form (DVa) binds and catalyzes substrate reduction, and an inactive form (DVi) exists for the resting enzyme. Only the active form of the enzyme need be considered during steady-state turnover. Determination of the rate constants defining these structural perturbations, from oxidized to reduced and reduced to oxidized states |
Desulfovibrio vulgaris |
? |
- |
? |
1.8.99.5 | more |
multiheme cytochrome c enzymes catalyse complex-multi-electron redox reactions and bind their substrates through the free electron pairs of a heteroatom to a free coordination position at an active-site hem group. Electrons are then provided or accepted by the tightly coupled chain of heme groups |
Wolinella succinogenes |
? |
- |
? |
1.8.99.5 | more |
MccA reduces sulfite, but not arsenate, selenate, selenite, hydroxylamine, hydrazine, fumarate, nitrate, thiosulfate, tetrathionate, polysulfide, or Fe(III). Nitrite is reduced only very slowly to ammonium |
Wolinella succinogenes |
? |
- |
? |
1.8.99.5 | more |
the enzyme catalyzes the reduction of sulfite to sulfide |
Cryptococcus neoformans var. neoformans |
? |
- |
- |
1.8.99.5 | more |
the enzyme catalyzes the reduction of sulfite to sulfide |
Cryptococcus neoformans var. neoformans ATCC MYA-565 |
? |
- |
- |
1.8.99.5 | more |
the enzyme catalyzes the reduction of sulfite to sulfide |
Cryptococcus neoformans var. neoformans JEC21 |
? |
- |
- |
1.8.99.5 | more |
two-state hypothesis for enzyme activity: an active form (DVa) binds and catalyzes substrate reduction, and an inactive form (DVi) exists for the resting enzyme. Only the active form of the enzyme need be considered during steady-state turnover. Determination of the rate constants defining these structural perturbations, from oxidized to reduced and reduced to oxidized states |
Desulfovibrio vulgaris Hildenborough |
? |
- |
? |
1.8.99.5 | nitrite + a [DsrC protein]-dithiol + 2 reduced acceptor |
- |
Desulfovibrio vulgaris |
? + a [DsrC protein]-disulfide + 2 acceptor + 2 H2O |
- |
? |
1.8.99.5 | nitrite + a [DsrC protein]-dithiol + 2 reduced acceptor |
- |
Clostridium pasteurianum |
? + a [DsrC protein]-disulfide + 2 acceptor + 2 H2O |
25% of the activity with sulfite |
? |