Recombinant Anaerocellum thermophilum Argininosuccinate synthase (argG)
Description
Enzyme Function and Biological Role
Argininosuccinate synthase (ArgG) catalyzes the ATP-dependent condensation of citrulline and aspartate to form argininosuccinate, a critical step in the urea cycle and arginine biosynthesis. In thermophiles like C. bescii, this enzyme operates optimally at elevated temperatures (~75°C) , making it inherently stable and suitable for high-temperature industrial processes.
Example Protocol:
2.2. Temperature-Sensitive Variants
Error-prone PCR and high-throughput screening (e.g., flow cytometry with fluorescent TIMER proteins) have been used to generate ArgG variants in E. coli . These variants enable precise metabolic control, such as auxotrophic switching at specific temperatures.
Performance Metrics:
| Property | Value (ArgG Variants) | Source |
|---|---|---|
| Thermosensitivity | 69% auxotrophic at 42°C, prototrophic at 30°C | |
| Growth Control | Tunable cell growth via temperature shifts |
3.1. Metabolic Engineering
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Citrulline Overproduction: Temperature-sensitive ArgG variants in E. coli dynamically regulate arginine pools, enhancing citrulline yields .
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Cofactor Recycling: ArgG supports nitrogen flux in synthetic pathways, analogous to its role in vascular smooth muscle cells where it sustains nitric oxide synthesis via citrulline recycling .
3.2. Industrial Enzymology
The thermostability of C. bescii enzymes makes recombinant ArgG a candidate for:
Comparative Analysis with Other Species
Research Gaps and Future Directions
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Structural Studies: No crystal structures of C. bescii ArgG are available, limiting rational design efforts.
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In Vivo Validation: The enzyme’s performance in non-E. coli hosts (e.g., thermophilic chassis) remains unexplored.
Product Specs
Target Background
KEGG: ate:Athe_1249
STRING: 521460.Athe_1249
