CATH Classification

Domain Context

CATH Clusters

Superfamily 3.30.70.2500
Functional Family

Enzyme Information

1.8.99.5
Dissimilatory sulfite reductase.
based on mapping to UniProt Q59109
(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(+).
-!- 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 catalyzes the reduction of sulfite to sulfide, while in sulfur oxidizers it catalyzes the opposite reaction. -!- 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. -!- This enzyme is different from EC 1.8.1.2 and EC 1.8.7.1, which are involved in sulfate assimilation.

UniProtKB Entries (1)

Q59109
DSRA_ARCFU
Archaeoglobus fulgidus DSM 4304
Sulfite reductase, dissimilatory-type subunit alpha

PDB Structure

PDB 3MMC
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Structure of the dissimilatory sulfite reductase from the hyperthermophilic archaeon Archaeoglobus fulgidus.
Schiffer, A., Parey, K., Warkentin, E., Diederichs, K., Huber, H., Stetter, K.O., Kroneck, P.M., Ermler, U.
J.Mol.Biol.