Involved in the degradation of glucose via the semi-phosphorylative Entner-Doudoroff pathway. Catalyzes the phosphorylation of 2-keto-3-deoxygluconate (KDG) to produce 2-keto-3-deoxy-6-phosphogluconate (KDPG). Can also use GTP, but not ADP or AMP, as a phosphoryl donor and 2-keto-D-gluconate (KG) as a phosphoryl acceptor. 2-dehydro-3-deoxy-D-gluconate + ATP = 2-dehydro-3-deoxy-6-phospho-D-gluconate + ADP + H(+) Mg(2+) is the most effective ion, but it can be replaced with Co(2+), Ni(2+), Zn(2+) or Mn(2+). kcat is 8.26 sec(-1) with KDG as substrate. kcat is 26.3 sec(-1) with KG as substrate. Optimum pH is around 8.5. Optimum temperature is 80 degrees Celsius. Extremely thermostable. Carbohydrate acid metabolism; 2-dehydro-3-deoxy-D-gluconate degradation; D-glyceraldehyde 3-phosphate and pyruvate from 2-dehydro-3-deoxy-D-gluconate: step 1/2. Homotetramer. Belongs to the carbohydrate kinase PfkB family.