Short-chain acyl-coenzyme A synthetases in Rhodopseudomonas sphaeroides

Two short-chain fatty acyl-CoA synthetases were extracted from the photosynthetic bacterium, Rhodopseudomonas sphaeroides, and partially purified by column chromatography on Sephacryl S-200 and DEAE-cellulose. One enzyme activated propionate, valerate, acrylate, butyrate, and acetate, and was designated as propionyl-CoA synthetase, since the highest activity and lowest Km value (0.6 mM) were observed with propionate. The other enzyme activated acetate, propionate and acrylate. It showed the highest activity and lowest Km value (0.37 mM) for acetate, and was identified as acetyl-CoA synthetase [EC 6.2.1.1].