The mmgA gene from Bacillus subtilis encodes a degradative acetoacetyl-CoA thiolase.
Early in sporulation, the mother cell compartment of Bacillus subtilis transcribes the mother cell metabolic gene (mmg) operon. The gene mmgA was assigned by other workers using sequence homology as an acetyl-CoA acetyltransferase [E.C. 2.3.1.9]. The gene was overexpressed in Escherichia coli, and the protein was purified by Ni(2+)-affinity chromatography. However, the expected MmgA-catalyzed biosynthesis of acetoacetyl-CoA from acetyl-CoA was undetectable by a standard UV assay, HPLC, and mass spectrometry. These methods indicated a preference for the reverse degradative thiolytic reaction, with a k(cat) of 80 s(-1), and a K(m) of 70 and 50 microM for CoA and acetoacetyl-CoA, respectively.
Reddick
Jason J
JJ
Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, NC, 27402-6170, USA. jjreddic@uncg.edu
Williams
Jayme K
JK
D000101:Acetyl-CoA C-Acetyltransferase / Q000302:isolation & purification* / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D009876:Operon; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013171:Spores, Bacterial / Q000378:metabolism; D013379:Substrate Specificity
D000101:Acetyl-CoA C-Acetyltransferase