Dimerization of assimilatory NADPH-dependent sulfite reductase reveals elements for diflavin reductase binding at a minimal interface.

uses a two protein complex with unique co-enzymes. To date, how the subunits interact so the co-enzymes can transfer electrons has remained a mystery because the complex is structurally dynamic, thus difficult to analyze with traditional methods. This study shows for the first time the structure of the enzyme complex that performs this unique chemistry.