6.2.1.B11	evolution	the ACD enzymes are considered to be primordial enzymes of ATP synthesis in the early evolution of life. The structure reveals a unique arrangement of the ACD subunits alpha and beta within an alpha2beta2-heterotetrameric complex. This arrangement significantly differs from other members of the superfamily. Residues Ser160alpha and Asp351alpha' are highly conserved throughout the ACD superfamily	
6.2.1.B11	physiological function	the enzyme is involved in acetate formation and energy conservation	
6.2.1.B11	physiological function	enzyme ACD is regulated through inhibition by ATP and diphosphate in the acetate-forming direction	
6.2.1.B11	physiological function	the NDP-forming acyl-CoA synthetases (ACDs) catalyze the conversion of various CoA thioesters to the corresponding acids, conserving their chemical energy in form of ATP. The ACDs are the major energy-conserving enzymes in sugar and peptide fermentation of hyperthermophilic archaea