title: Methods for analysis of acetyl-CoA synthase applications to bacterial and archaeal systems.
abstract: The nickel- and iron-containing enzyme acetyl-CoA synthase (ACS) catalyzes de novo synthesis as well as overall cleavage of acetyl-CoA in acetogens, various other anaerobic bacteria, methanogens, and other archaea. The enzyme contains a unique active site metal cluster, designated the A cluster, that consists of a binuclear Ni-Ni center bridged to an [Fe(4)S(4)] cluster. In bacteria, ACS is tightly associated with CO dehydrogenase to form the bifunctional heterotetrameric enzyme CODH/ACS, whereas in archaea, ACS is a component of the large multienzyme complex acetyl-CoA decarbonylase/synthase (ACDS), which comprises five different subunits that make up the subcomponent proteins ACS, CODH, and a corrinoid enzyme. Characteristic properties of ACS are discussed, and key methods are described for analysis of the enzyme's multiple redox-dependent activities, including overall acetyl-CoA synthesis, acetyltransferase, and an isotopic exchange reaction between the carbonyl group of acetyl-CoA and CO. Systematic measurement of these activities, applied to different ACS protein forms, provides insight into the ACS catalytic mechanism and physiological functions in both CODH/ACS and ACDS systems.
authors.affiliation: Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Grahame
mesh_terms: D000106:Acetate-CoA Ligase / Q000378:metabolism*; D001105:Archaea / Q000201:enzymology*; D001419:Bacteria / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D008954:Models, Biological
chemical_list: D000106:Acetate-CoA Ligase