Sulfite reductase (NADPH)

In enzymology, a sulfite reductase (NADPH) is an enzyme that catalyzes the chemical reaction


 * hydrogen sulfide + 3 NADP+ + 3 H2O $$\rightleftharpoons$$ sulfite + 3 NADPH + 3 H+

The 3 substrates of this enzyme are hydrogen sulfide, NADP+, and H2O, whereas its 3 products are sulfite, NADPH, and H+.

This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is hydrogen-sulfide:NADP+ oxidoreductase. Other names in common use include sulfite (reduced nicotinamide adenine dinucleotide phosphate), reductase, NADPH-sulfite reductase, NADPH-dependent sulfite reductase, H2S-NADP oxidoreductase, and sulfite reductase (NADPH2). This enzyme participates in selenoamino acid metabolism and sulfur metabolism. It has 4 cofactors: FAD, Iron, Heme, and FMN.

Structural studies
As of late 2007, 15 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , and.