Glycogen phosphorylase, the product of the glgP Gene, catalyzes glycogen breakdown by removing glucose units from the nonreducing ends in Escherichia coli

To understand the biological function of bacterial glycogen phosphorylase (GlgP), we have produced and characterized Escherichia coli cells with null or altered glgP expression. glgP deletion mutants (ΔglgP) totally lacked glycogen phosphorylase activity, indicating that all the enzymatic activity i...

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Bibliographic Details
Authors: Alonso Casajús, Nora, Dauvillee, David, Viale Bailone, Alejandro M., Muñoz Pérez, Francisco José, Baroja Fernández, Edurne, Morán Zorzano, María Teresa, Eydallin, Gustavo, Ball, Steven, Pozueta Romero, Javier
Format: article
Status:Published version
Publication Date:2006
Country:España
Institution:Universidad Pública de Navarra
Repository:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/32088
Online Access:https://hdl.handle.net/2454/32088
Access Level:Open access
Keyword:Bacterial glycogen phosphorylase (GlgP)
Escherichia coli
Description
Summary:To understand the biological function of bacterial glycogen phosphorylase (GlgP), we have produced and characterized Escherichia coli cells with null or altered glgP expression. glgP deletion mutants (ΔglgP) totally lacked glycogen phosphorylase activity, indicating that all the enzymatic activity is dependent upon the glgP product. Moderate increases of glycogen phosphorylase activity were accompanied by marked reductions of the intracellular glycogen levels in cells cultured in the presence of glucose. In turn, both glycogen content and rates of glycogen accumulation in ΔglgP cells were severalfold higher than those of wild-type cells. These defects correlated with the presence of longer external chains in the polysaccharide accumulated by ΔglgP cells. The overall results thus show that GlgP catalyzes glycogen breakdown and affects glycogen structure by removing glucose units from the polysaccharide outer chains in E. coli.