Catalyzes the formation of acetyl phosphate from acetate and ATP. Can also catalyze the reverse reaction. Appears to favor the formation of acetate. Involved in the secretion of excess carbohydrate. acetate + ATP = acetyl phosphate + ADP Mg(2+). Can also accept Mn(2+). Induced by glucose excess, the induction may be mediated by CcpA transcriptional regulator. Metabolic intermediate biosynthesis; acetyl-CoA biosynthesis; acetyl-CoA from acetate: step 1/2. Homodimer. Belongs to the acetokinase family.