An Escherichia coli mutant producing a truncated inactive form of GlgC synthesizes glycogen: Further evidences for the occurrence of various important sources of ADPglucose in enterobacteria

• Published in: FEBS letters 2007-09, Vol.581 (23), p.4417-4422
• Main Authors: Eydallin, Gustavo, Morán-Zorzano, María Teresa, Muñoz, Francisco José, Baroja-Fernández, Edurne, Montero, Manuel, Alonso-Casajús, Nora, Viale, Alejandro M., Pozueta-Romero, Javier
• Format: Article
• Language: English
• Subjects: AC70R1–504; Adenosine Diphosphate Glucose - metabolism; adenosine diphosphate sugar pyrophosphatase; ADPG; ADPG pyrophosphorylase; ADPglucose; AGPase; AspP; Blotting, Western; Carbohydrate metabolism; electron microscopy; Electrophoresis, Polyacrylamide Gel; Enterobacteriaceae - genetics; Enterobacteriaceae - metabolism; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli - ultrastructure; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; GlgA; Glucose-1-Phosphate Adenylyltransferase - genetics; Glucose-1-Phosphate Adenylyltransferase - metabolism; Glycogen - metabolism; Glycogen - ultrastructure; glycogen synthase; IPTG; isopropyl-β-d-thiogalactopyranoside; Microscopy, Electron, Transmission; Molecular Sequence Data; Mutation; unit of enzyme activity
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2007.08.016

AC70R1–504 Escherichia coli mutants possess a glgC ∗ gene with a nucleotide change resulting in a premature stop codon that renders a truncated, inactive form of GlgC. Cells over-expressing the wild type glgC, but not those over-expressing the AC70R1–504 glgC ∗, accumulated high ADPglucose and glycogen levels. AC70R1–504 mutants accumulated glycogen, whereas Δ glgCAP deletion mutants lacking the whole glycogen biosynthetic machinery displayed a glycogen-less phenotype. AC70R1–504 cells with enhanced glycogen synthase activity accumulated high glycogen levels. By contrast, AC70R1–504 cells with high ADPG hydrolase activity accumulated low glycogen. These data further confirm that enterobacteria possess various sources of ADPglucose linked to glycogen biosynthesis.