The Stroupe Laboratory is interested in the structural underpinnings of bacterial sulfur metabolism. The superstar of this process is a multicomponent enzyme called sulfite reductase, which performs a unique six electron reduction of sulfite to sulfide for incorporation into sulfur-containing amino acids and cofactors. We use a combination of X-ray crystallography and cryogenic electron microscopy, along with biochemical assays, to understand this complex, but powerful, oxidoreductase.