Analysis of genes involved in glycogen degradation in Escherichia coli

• Published in: FEMS microbiology letters 2017-02, Vol.364 (3), p.fnx016
• Main Authors: Strydom, Lindi, Jewell, Jonathan, Meier, Michael A., George, Gavin M., Pfister, Barbara, Zeeman, Samuel, Kossmann, Jens, Lloyd, James R.
• Format: Article
• Language: English
• Subjects: Bacteria; Coliforms; Degradation; E coli; Enzymes; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Genes, Bacterial; Glucosyltransferases - genetics; Glucosyltransferases - metabolism; Glycogen; Glycogen - metabolism; Glycogen Debranching Enzyme System - genetics; Glycogen phosphorylase; Glycogen Phosphorylase - genetics; Glycogen Phosphorylase - metabolism; Maltodextrin; Maltodextrin phosphorylase; Microbiology; Oligosaccharides; Phosphorylase; Polymers; Polysaccharides - metabolism
• ISSN: 1574-6968; 0378-1097; 1574-6968
• DOI: 10.1093/femsle/fnx016

Abstract Escherichia coli accumulate or degrade glycogen depending on environmental carbon supply. Glycogen phosphorylase (GlgP) and glycogen debranching enzyme (GlgX) are known to act on the glycogen polymer, while maltodextrin phosphorylase (MalP) is thought to remove maltodextrins released by GlgX. To examine the roles of these enzymes in more detail, single, double and triple mutants lacking all their activities were produced. GlgX and GlgP were shown to act directly on the glycogen polymer, while MalP most likely catabolised soluble malto-oligosaccharides. Interestingly, analysis of a triple mutant lacking all three enzymes indicates the presence of another enzyme that can release maltodextrins from glycogen. Analysis of Escherichia coli lacking combinations of MalP, GlgX and GlgP indicates that they are all involved in glycogen degradation.