Phosphopentose epimerase

Phosphopentose epimerase (also known as ribulose-phosphate 3-epimerase and ribulose 5-phosphate 3-epimerase)(EC5.1.3.1) is a metalloprotein that catalyzes the interconversion between D-ribulose 5-phosphate and D-xylulose 5-phosphate.

This reversible conversion is required for carbon fixation in plants – through the Calvin cycle – and for the nonoxidative phase of the pentose phosphate pathway. This enzyme has also been implicated in additional pentose and glucuronate interconversions.