In enzymology, a D-proline reductase (dithiol) () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 5-aminopentanoate and lipoate, whereas its two products are D-proline and dihydrolipoate.
This enzyme belongs to the family of oxidoreductases, specifically those acting on X-H and Y-H to form an X-Y bond with a disulfide as acceptor. The systematic name of this enzyme class is 5-aminopentanoate:lipoate oxidoreductase (cyclizing). This enzyme participates in arginine and proline metabolism. It employs one cofactor, pyruvate.