Allosteric regulation of the partitioning of glucose-1-phosphate between glycogen and trehalose biosynthesis in Mycobacterium tuberculosis

• Published in: Biochimica et biophysica acta 2015-01, Vol.1850 (1), p.13-21
• Main Authors: Asención Diez, Matías D., Demonte, Ana M., Syson, Karl, Arias, Diego G., Gorelik, Andrii, Guerrero, Sergio A., Bornemann, Stephen, Iglesias, Alberto A.
• Format: Article
• Language: English
• Subjects: ADP-glucose pyrophosphorylase; Allosteric Regulation; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Glucose-1-Phosphate Adenylyltransferase - genetics; Glucose-1-Phosphate Adenylyltransferase - metabolism; Glucose-6-phosphate; Glucose-6-Phosphate - metabolism; Glucosephosphates - metabolism; Glucosyltransferases - genetics; Glucosyltransferases - metabolism; Glycogen - biosynthesis; Glycogen synthase; Glycogen Synthase - genetics; Glycogen Synthase - metabolism; Kinetics; Metabolic Networks and Pathways; Models, Biological; Mycobacterium tuberculosis; Mycobacterium tuberculosis - enzymology; Mycobacterium tuberculosis - metabolism; Phosphoenolpyruvate; Recombinant Proteins - metabolism; Substrate Specificity; Trehalose - biosynthesis; Trehalose-6-phosphate synthase; UDP-glucose pyrophosphorylase; UTP-Glucose-1-Phosphate Uridylyltransferase - genetics; UTP-Glucose-1-Phosphate Uridylyltransferase - metabolism
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2014.09.023

Mycobacterium tuberculosis is a pathogenic prokaryote adapted to survive in hostile environments. In this organism and other Gram-positive actinobacteria, the metabolic pathways of glycogen and trehalose are interconnected. In this work we show the production, purification and characterization of recombinant enzymes involved in the partitioning of glucose-1-phosphate between glycogen and trehalose in M. tuberculosis H37Rv, namely: ADP-glucose pyrophosphorylase, glycogen synthase, UDP-glucose pyrophosphorylase and trehalose-6-phosphate synthase. The substrate specificity, kinetic parameters and allosteric regulation of each enzyme were determined. ADP-glucose pyrophosphorylase was highly specific for ADP-glucose while trehalose-6-phosphate synthase used not only ADP-glucose but also UDP-glucose, albeit to a lesser extent. ADP-glucose pyrophosphorylase was allosterically activated primarily by phosphoenolpyruvate and glucose-6-phosphate, while the activity of trehalose-6-phosphate synthase was increased up to 2-fold by fructose-6-phosphate. None of the other two enzymes tested exhibited allosteric regulation. Results give information about how the glucose-1-phosphate/ADP-glucose node is controlled after kinetic and regulatory properties of key enzymes for mycobacteria metabolism. This work increases our understanding of oligo and polysaccharides metabolism in M. tuberculosis and reinforces the importance of the interconnection between glycogen and trehalose biosynthesis in this human pathogen. •Nucleotide-glucose synthesis in Mycobacterium tuberculosis was analyzed.•The characterization of four enzymes involved in glucose-1P partitioning is reported.•Mycobacterial ADP-glucose pyrophosphorylase is allosterically regulated.•Trehalose-6P synthase exhibits higher catalytic efficiency for ADP-glucose.•Trehalose-6P synthase is activated by fructose-6P.