Involved in catabolism of D-apiose. Catalyzes the phosphorylation of L-erythrulose to L-erythrulose 1-phosphate (PubMed:29867142). Can also phosphorylate D-erythrulose and dihydroxyacetone in vitro (PubMed:29867142). ATP + L-erythrulose = ADP + H(+) + L-erythrulose 1-phosphate kcat is 2.76 sec(-1) with L-erythrulose as substrate. kcat is 0.72 sec(-1) with D-erythrulose as substrate. kcat is 1.34 sec(-1) with dihydroxyacetone as substrate. Carbohydrate metabolism.