The enzyme has great affinity for glucose and mannose. ATP + D-glucose = ADP + D-glucose 6-phosphate + H(+) ATP + D-mannose = ADP + D-mannose 6-phosphate + H(+) Competitively inhibited by 2-deoxy-glucose. Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate and glycerone phosphate from D-glucose: step 1/4. Carbohydrate metabolism; mannose metabolism. Homodimer. Belongs to the ROK (NagC/XylR) family.