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[A plasmid vector with temperature-controlled gene expression].
Bioorganicheskaia Khimiia
|April 1, 1985
Summary
Researchers engineered plasmids for controlled gene expression. This system significantly boosted beta-lactamase and beta-galactosidase production at elevated temperatures, demonstrating a powerful tool for biotechnology.
Area of Science:
- Molecular Biology
- Genetic Engineering
- Biotechnology
Background:
- The pBR327 plasmid was modified by removing a 169 bp fragment containing the bla gene promoter p3.
- Lambda phage DNA fragment (TaqI/BglII) containing promoter pR and gene cI was utilized for cloning.
Purpose of the Study:
- To construct novel plasmids for temperature-inducible gene expression.
- To evaluate the expression levels of reporter genes under the control of lambda phage promoter pR and cI repressor.
Main Methods:
- Deletion of a promoter fragment from pBR327 plasmid.
- Ligation of lambda phage DNA fragment into the modified plasmid to create pCE119.
- Construction of pCEZ12 plasmid for expression of a semi-synthetic beta-galactosidase gene.
- Culturing cells containing engineered plasmids at different temperatures (32°C and 42°C).
Main Results:
- Plasmid pCE119 demonstrated a 100-fold increase in beta-lactamase production at 42°C compared to 32°C.
- Plasmid pCEZ12 showed approximately a 300-fold higher yield of beta-galactosidase at 42°C than at 32°C.
- The lambda phage promoter pR and cI repressor system effectively controlled gene expression in a temperature-dependent manner.
Conclusions:
- Engineered plasmids pCE119 and pCEZ12 provide a robust system for high-level, temperature-inducible protein production.
- This inducible expression system offers significant advantages for biotechnological applications requiring controlled protein yields.