In enzymology, a ribulokinase is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are ATP, L-ribulose, and D-ribulose, whereas its 3 products are ADP, L-ribulose 5-phosphate, and D-ribulose 5-phosphate. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:L(or D)-ribulose 5-phosphotransferase. Other names in common use include ribulokinase (phosphorylating), and L-ribulokinase. This enzyme participates in pentose and glucuronate interconversions.