ATP + D-tagatofuranose 6-phosphate = ADP + D-tagatofuranose 1,6-bisphosphate + H(+) Carbohydrate metabolism; D-tagatose 6-phosphate degradation; D-glyceraldehyde 3-phosphate and glycerone phosphate from D-tagatose 6-phosphate: step 1/2. Belongs to the carbohydrate kinase PfkB family. LacC subfamily.