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

Abstract

BACKGROUND:

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.

RESULTS:

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.

CONCLUSIONS:

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.

GENERAL SIGNIFICANCE:

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.

• Authors: Matías D Asención Diez, Ana M Demonte, Karl Syson, Diego G Arias, Andrii Gorelik, Sergio A Guerrero, Stephen Bornemann, Alberto A Iglesias
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1850 Issue 1 Pg. 13-21 (Jan 2015) ISSN: 0006-3002 [Print] Netherlands
• PMID: 25277548 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014. Published by Elsevier B.V.

Chemical References

• Bacterial Proteins
• Glucosephosphates
• Recombinant Proteins
• Glucose-6-Phosphate
• Glycogen
• Trehalose
• glucose-1-phosphate
• Glucosyltransferases
• Glycogen Synthase
• trehalose-6-phosphate synthase
• Glucose-1-Phosphate Adenylyltransferase
• UTP-Glucose-1-Phosphate Uridylyltransferase

Topics

• Allosteric Regulation
• Bacterial Proteins (genetics, metabolism)
• Glucose-1-Phosphate Adenylyltransferase (genetics, metabolism)
• Glucose-6-Phosphate (metabolism)
• Glucosephosphates (metabolism)
• Glucosyltransferases (genetics, metabolism)
• Glycogen (biosynthesis)
• Glycogen Synthase (genetics, metabolism)
• Kinetics
• Metabolic Networks and Pathways
• Models, Biological
• Mycobacterium tuberculosis (enzymology, metabolism)
• Recombinant Proteins (metabolism)
• Substrate Specificity
• Trehalose (biosynthesis)
• UTP-Glucose-1-Phosphate Uridylyltransferase (genetics, metabolism)