Utilization of L-ascorbate by Escherichia coli K-12: Assignments of functions to products of the yjf-sga and yia-sgb operons

Shan Yew Wen Shan Yew, J. A. Gerlt

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Escherichia coli K-12 can ferment L-ascorbate. The operon encoding catabolic enzymes in the utilization of L-ascorbate (ula) has been identified; this operon of previously unknown function had been designated the yif-sga operon. Three enzymes in the pathway that produce D-xylulose 5-phosphate have been functionally characterized: 3-keto-L-gulonate 6-phosphate decarboxylase (UlaD), L-xylulose 5-phosphate 3-epimerase (UlaE), and L-ribulose 5-phosphate 4-epimerase (UlaF). Several products of the yia-sgb operon were also functionally characterized, although the substrate and physiological function of the operon remain unknown: 2,3-diketo-L-gulonate reductase (YiaK), 3-keto-L-gulonate kinase (LyxK), 3-keto-L-gulonate 6-phosphate decarboxylase (SgbH), and L-ribulose 5-phosphate 4-epimerase (SgbE).

Original languageEnglish (US)
Pages (from-to)302-306
Number of pages5
JournalJournal of bacteriology
Issue number1
StatePublished - Jan 4 2002


ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

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