Catalyzes the reversible formation of acetate and ATP from acetyl-CoA by using ADP and phosphate. Can use other substrates such as phenylacetyl-CoA, indoleacetyl-CoA and isobutyryl-CoA, but not succinyl-CoA. Seems to be involved primarily in the degradation of aryl-CoA esters to the corresponding acids. Participates in the conversion of acetyl-CoA to acetate and in the degradation of branched-chain amino acids via branched-chain-acyl-CoA esters. acetate + ATP + CoA = acetyl-CoA + ADP + phosphate kcat is 115 sec(-1) for ADP. kcat is 21 sec(-1) for GDP. kcat is 117 sec(-1) for phosphate. kcat is 42 sec(-1) for acetyl-CoA. kcat is 8 sec(-1) for isobutyryl-CoA. kcat is 138 sec(-1) for phenylacetyl-CoA. kcat is 68 sec(-1) for ATP. kcat is 27 sec(-1) for GTP. kcat is 70 sec(-1) for CoA. kcat is 67 sec(-1) for acetate. kcat is 22 sec(-1) for isobutyrate. kcat is 66 sec(-1) for indoleacetate. kcat is 89 sec(-1) for phenylacetate. Optimum pH is 9.0 (at 80 degrees Celsius). Optimum temperature is above 90 degrees Celsius (at pH 8.0). Heterotetramer of two alpha and two beta subunits. Belongs to the acetate CoA ligase alpha subunit family.