title: Evidence for a complex of three beta-oxidation enzymes in Escherichia coli: induction and localization.
abstract: The enzymes for beta-oxidation of fatty acids in inducible and constitutive strains of Escherichia coli were assayed in soluble and membrane fractions of disrupted cells by using fatty acid and acyl-coenzyme A (CoA) substrates containing either 4 or 16 carbon atoms in the acyl moieties. Cell fractionation was monitored, using succinic dehydrogenase as a membrane marker and glucose 6-phosphate dehydrogenase as a soluble marker. Acyl-CoA synthetase activity was detected exclusively in the membrane fraction, whereas acyl-CoA dehydrogenase, 3-hydroxyacyl-CoA dehydrogenase, enoyl-CoA hydratase, and 3-ketoacyl-CoA thiolase activities that utilized both C4 and C16 acyl-CoA substrates were isolated from the soluble fraction. 3-Hydroxyacyl-CoA dehydrogenase, enoyl-CoA hydratase, and 3-ketoacyl-CoA thiolase activities assayed with both C4 and C16 acyl-CoA substrates co-chromatographed on gel filtration and ion-exchange columns and cosedimented in glycerol gradients. The data show that these three enzyme activities of the fad regulon can be isolated as a multienzyme complex. This complex dissociates in very dilute preparations; however, in those preparations where the three activities are separated, the fractionated species retain activity with both C4 and C16 acyl-CoA substrates.
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000096:biosynthesis* / Q000378:metabolism; D000085:Acetates / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000096:biosynthesis* / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism; D044944:Acyl-CoA Dehydrogenases / Q000096:biosynthesis / Q000378:metabolism; D000217:Acyltransferases / Q000096:biosynthesis*; D002462:Cell Membrane / Q000201:enzymology; D003066:Coenzyme A Ligases / Q000096:biosynthesis / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D004746:Enoyl-CoA Hydratase / Q000096:biosynthesis* / Q000378:metabolism; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D006836:Hydro-Lyases / Q000096:biosynthesis*; D009097:Multienzyme Complexes / Q000096:biosynthesis* / Q000378:metabolism; D009829:Oleic Acids / Q000378:metabolism; D013347:Subcellular Fractions
chemical_list: D000085:Acetates; D000214:Acyl Coenzyme A; D005227:Fatty Acids; D009097:Multienzyme Complexes; D009829:Oleic Acids; D015094:3-Hydroxyacyl CoA Dehydrogenases; D044944:Acyl-CoA Dehydrogenases; D000217:Acyltransferases; D000102:Acetyl-CoA C-Acyltransferase; D006836:Hydro-Lyases; D004746:Enoyl-CoA Hydratase; D003066:Coenzyme A Ligases