CATH Classification

Domain Context

CATH Clusters

Superfamily 3.30.70.3340
Functional Family

Enzyme Information

1.8.99.5
Dissimilatory sulfite reductase.
based on mapping to UniProt Q59110
(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 3MMB
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Reaction cycle of the dissimilatory sulfite reductase from Archaeoglobus fulgidus.
Parey, K., Warkentin, E., Kroneck, P.M., Ermler, U.
Biochemistry