| 英文名 |
dissimilatory sulfite reductase |
| Example Structure |
 |
| 别名 |
anaerobic sulfatase-maturating enzyme, anSME, anSMEcpe, AtsB, Cys-type anaerobic sulfatase-maturating enzyme, nSMEcpe |
| EC Number |
1.8.99.5 |
| CAS编号 |
|
| Comments |
Contain siroheme. The enzyme is essential in prokaryotic sulfur-based energy metabolism, including sulfate/sulfite reducing organisms, sulfur-oxidizing bacteria, and organosulfonate reducers. In sulfur reducers it catalyses the reduction of sulfite to sulfide (reaction 1 in the right to left direction), while in sulfur oxidizers it catalyses the opposite reaction (reaction 2 in the left to right direction) [1]. The reaction involves the small protein DsrC, which is present in all the organisms that contain dissimilatory sulfite reductase. During the process an intramolecular disulfide bond is formed between two L-cysteine residues of DsrC. This disulfide can be reduced by a number of proteins including DsrK and TcmB [5]. This enzyme is different from EC 1.8.1.2, assimilatory sulfite reductase (NADPH), and EC 1.8.7.1, assimilatory sulfite reductase (ferredoxin), which are involved in sulfate assimilation. |
| Cofactor |
siroheme |
| History |
|
| Reactions |
(1) Hydrogen sulfide + a [DsrC protein]-disulfide + 2 acceptor + 3 H(2)O = sulfite + a [DsrC protein]-dithiol + 2 reduced acceptor + 2 H(+). (2) A [DsrC protein]-S-sulfanyl-L-cysteine + 3 acceptor + 3 H(2)O = sulfite + a [DsrC protein]-disulfide + 3 reduced acceptor + 2 H(+). |
