biostudies-literatureUnknown180(24)Cha CJRhodococcus rhodochrous N75 is able to metabolize 4-methylcatechol via a modified beta-ketoadipate pathway. This organism has been shown to activate 3-methylmuconolactone by the addition of coenzyme A (CoA) prior to hydrolysis of the butenolide ring. A lactone-CoA synthetase is induced by growth of R. rhodochrous N75 on p-toluate as a sole source of carbon. The enzyme has been purified 221-fold by ammonium sulfate fractionation, hydrophobic chromatography, gel filtration, and anion-exchange chromatography. The enzyme, termed 3-methylmuconolactone-CoA synthetase, has a pH optimum of 8.0, a native Mr of 128,000, and a subunit Mr of 62,000, suggesting that the enzyme is homodimeric. The enzyme is very specific for its 3-methylmuconolactone substrate and displays little or no activity with othJournal of bacteriology6668-73https://www.ebi.ac.uk/biostudies/studies/S-EPMC107772biostudies-literatureThe modified beta-ketoadipate pathway in Rhodococcus rhodochrous N75: enzymology of 3-methylmuconolactone metabolism.PMC107772Cha CJBruce NCCain RBfalseThe modified beta-ketoadipate pathway in Rhodococcus rhodochrous N75: enzymology of 3-methylmuconolactone metabolism.Rhodococcus rhodochrous N75 is able to metabolize 4-methylcatechol via a modified beta-ketoadipate pathway. This organism has been shown to activate 3-methylmuconolactone by the addition of coenzyme A (CoA) prior to hydrolysis of the butenolide ring. A lactone-CoA synthetase is induced by growth of R. rhodochrous N75 on p-toluate as a sole source of carbon. The enzyme has been purified 221-fold by ammonium sulfate fractionation, hydrophobic chromatography, gel filtration, and anion-exchange chromatography. The enzyme, termed 3-methylmuconolactone-CoA synthetase, has a pH optimum of 8.0, a native Mr of 128,000, and a subunit Mr of 62,000, suggesting that the enzyme is homodimeric. The enzyme is very specific for its 3-methylmuconolactone substrate and displays little or no activity with oth1998-01-01T00:00:00Z1998 Dec2025-04-04T09:50:12.327Z2025-02-19T04:02:24.414ZS-EPMC107772985201310.1128/JB.180.24.6668-6673.1998