. "Cytosolic uridine phosphorylase (isoforms UPP1 and UPP2) catalyzes the reversible reactions of uridine or deoxyuridine with orthophosphate to yield uracil and ribose 1-phosphate or deoxyribose 1-phosphate (Watanabe and Uchida 1995; Johansson, 2003). The active form of UPP1 is a dimer (Rooslid et al. 2009)."^^ . . . . . . . . "(deoxy)uridine + orthophosphate <=> uracil + (deoxy)ribose 1-phosphate [UPP]"^^ . "2.4.2.3"^^ . . . . .