Galactaro δ-lactone isomerase: Lactone isomerization by a member of the amidohydrolase superfamily

Jason T. Bouvier, Fiona P. Groninger-Poe, Matthew Vetting, Steven C. Almo, John A. Gerlt

Research output: Contribution to journalArticle


Agrobacterium tumefaciens strain C58 can utilize d-galacturonate as a sole source of carbon via a pathway in which the first step is oxidation of D-galacturonate to D-galactaro-1,5-lactone. We have identified a novel enzyme, D-galactarolactone isomerase (GLI), that catalyzes the isomerizaton of D-galactaro-1,5-lactone to D-galactaro-1,4-lactone. GLI, a member of the functionally diverse amidohydrolase superfamily, is a homologue of LigI that catalyzes the hydrolysis of 2-pyrone-4,6-dicarboxylate in lignin degradation. The ability of GLI to catalyze lactone isomerization instead of hydrolysis can be explained by the absence of the general basic catalysis used by 2-pyrone-4,6-dicarboxylate lactonase.

Original languageEnglish (US)
Pages (from-to)614-616
Number of pages3
Issue number4
StatePublished - Feb 4 2014


ASJC Scopus subject areas

  • Biochemistry

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