Recombinant Synechocystis sp. Glycerol kinase (glpK)
Description
Introduction
Glycerol kinase (glpK), encoded by the glpK gene, catalyzes the first step in glycerol metabolism by phosphorylating glycerol to glycerol-3-phosphate. In Synechocystis sp. PCC 6803, this enzyme has garnered attention for its dual roles in metabolic regulation and biotechnological applications. Recombinant glpK refers to its engineered expression in heterologous systems, enabling studies of its function, optimization, and integration into synthetic pathways.
Genomic and Functional Context
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Genomic Organization: In Synechocystis, glpK is part of a larger metabolic network linked to osmolyte synthesis. Its expression is upregulated under salt stress, alongside genes involved in glucosylglycerol (GG) degradation .
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Neutral Site Integration: Recent studies highlight glpK as a candidate for recombinant protein expression. A neutral site (A2304) in Synechocystis sp. PCC 7002, flanked by divergently transcribed genes, was identified for stable heterologous expression .
Biochemical Properties
| Parameter | Value | Source |
|---|---|---|
| Substrate (glycerol) | 8–74-fold induction | |
| Enzyme Activity | Dependent on ATP | |
| Allosteric Regulation | Inhibited by FBP |
Metabolic Regulation
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Transcriptional Control: glpK expression is tightly regulated by glycerol availability. In Synechocystis, its transcripts increase 8-fold under salt stress, correlating with GG degradation pathways .
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Post-Translational Modulation: Adaptive mutations in glpK (e.g., reduced FBP sensitivity) enhance glycerol metabolism efficiency in engineered systems .
Recombinant Applications
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Biotechnological Engineering: glpK has been engineered to improve glycerol kinase activity in E. coli for biofuel production, with mutations reducing allosteric inhibition .
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Synthetic Biology: Neutral site integration in Synechocystis enables stable expression of recombinant proteins, leveraging its photosynthetic chassis for scalable production .
Future Directions
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Metabolic Engineering: Optimizing glpK for glycerol-based bioeconomies in extremophiles.
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Systems Biology: Elucidating regulatory networks linking glpK to osmolyte synthesis and stress responses.
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Industrial Applications: Exploring glpK as a tool for bioproduction of polyols and biofuels.
Product Specs
Target Background
KEGG: syn:slr1672
STRING: 1148.SYNGTS_1779
