Recombinant Mycobacterium avium Glucose-6-phosphate isomerase (pgi), partial
Description
Enzymatic Function and Biological Role
Phosphoglucose isomerase (Pgi) is essential for central carbon metabolism. In mycobacteria, it facilitates:
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Glycolysis: Conversion of G6P to F6P for energy production .
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Gluconeogenesis: Reverse reaction to generate G6P for biosynthetic pathways .
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Cell wall biosynthesis: G6P serves as a precursor for glycopeptidolipids (GPLs) and arabinogalactan, critical components of the mycobacterial cell envelope .
Studies on M. smegmatis pgi mutants revealed glucose auxotrophy, as G6P is required for cell wall synthesis. Complementation with the pgi gene restored growth on non-glucose carbon sources .
Recombinant Expression Strategies
While no direct reports exist for M. avium Pgi, analogous workflows for recombinant mycobacterial proteins include:
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Cloning: Amplification of the pgi gene fragment and insertion into expression vectors (e.g., pET21b or pMV261) .
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Host systems: Escherichia coli or M. smegmatis as heterologous hosts for protein production .
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Purification: Affinity chromatography using histidine tags or other fusion partners .
For example, M. avium rhamnosyltransferase (rtfA) was functionally expressed in M. smegmatis, enabling structural and enzymatic studies . A similar approach could apply to M. avium Pgi.
Applications and Research Implications
A partial recombinant Pgi could be used for:
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Enzyme kinetics: Characterizing substrate specificity and inhibitor screening.
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Structural studies: Solving crystal structures of functional domains .
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Drug discovery: Targeting Pgi to disrupt M. avium metabolism or virulence .
In M. smegmatis, pgi deletion mutants showed 1,000-fold reduced enzyme activity, underscoring its essentiality . Similar approaches could validate M. avium Pgi as a therapeutic target.
Challenges and Knowledge Gaps
Product Specs
Target Background
KEGG: mav:MAV_1068
