Involved in acetate metabolism. Catalyzes the reversible interconversion of acetyl-CoA and acetyl phosphate. The direction of the overall reaction changes depending on growth conditions. Required for acetate recapture but not for acetate excretion when this organism is grown on ethanolamine (EA); is unable to complement an eutD deletion during growth on EA (PubMed:16272400). Works with proprionate kinase PduW to capture exogenous propionate and regenerate propionyl-CoA during degradation of propionate and 1,2-propanediol (1,2-PD) (PubMed:12700259). acetyl-CoA + phosphate = acetyl phosphate + CoA phosphate + propanoyl-CoA = CoA + propanoyl phosphate Allosterically inhibited by NADH. Metabolic intermediate biosynthesis; acetyl-CoA biosynthesis; acetyl-CoA from acetate: step 2/2. Homohexamer. The N-terminal region seems to be important for proper quaternary structure. The C-terminal region contains the substrate-binding site (By similarity). Decreased propionate kinase activity, cells grow to lower density on 1,2-PD and excrete more propionate into the medium (PubMed:12700259). A double acs-pta deletion excretes but no longer recpautres acetate (PubMed:16272400). In the N-terminal section; belongs to the CobB/CobQ family. In the C-terminal section; belongs to the phosphate acetyltransferase and butyryltransferase family.