Acetyl-CoA decarbonylase/synthase complex from Archaeoglobus fulgidus.

The acetyl-CoA decarbonylase/synthase (ACDS) multienzyme complex catalyzes the reversible cleavage and synthesis of acetyl-CoA in methanogens. This report of the enzyme complex in Archaeoglobus fulgidus demonstrates the existence of a functional ACDS complex in an organism that is not a methanogen. The A. fulgidus enzyme complex contained five subunits of 89, 72, 50, 49.5, and 18.5 kDa, and it catalyzed the overall synthesis of acetyl-CoA according to the following reaction: CO2 + 2 Fdred(Fe2+) + 2 H+ + CH3 - H4SPt + CoA <==> acetyl-CoA + H4SPt + 2 Fdox(Fe3+) + H2O where Fd is ferredoxin, and CH3-H4SPt and H4SPt denote N5-methyl-tetrahydrosarcinapterin and tetrahydrosarcinapterin, respectively.