Definition of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)

1. A magnesium-dependent enzyme (EC 4.1.1.39), the primary enzyme of carbon dioxide fixation in plants and autotrophic bacteria. It catalyzes the synthesis of 3-phospho-D-glycerate from ribulose bisphosphate and also the oxidation of ribulose bisphosphate by O2 to 3-phospho-D-glycerate and 2-phosphoglycol