| Autor: |
Cranenburgh, Rocky M., Lewis, Kathryn S., Hanak, Julian A. J. |
| Předmět: |
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| Zdroj: |
Journal of Molecular Microbiology & Biotechnology; 2004, Vol. 7 Issue 4, p197-203, 7p |
| Abstrakt: |
The Escherichia coli strain DH1lacdapD enables plasmid selection and maintenance that is free from antibiotics and selectable marker genes. This is achieved by using only the lac operator sequence as a selectable element. This strain is currently used to generate high copy number plasmids with no antibiotic resistance genes for use as DNA vaccines and for expression of recombinant proteins. Until now these have been limited to pUC-based plasmids containing a high copy number pMB1-derived origin of replication, and the principle lacO1 and auxiliary lacO3 operators. In this study we have shown that this system can also be used to select and maintain pBR322-based plasmids with the lower copy number pMB1 origin of replication, and that lacO1 alone or a palindromic version of lacO1 can provide a sufficient level of repressor titration for plasmid selection. This is advantageous for recombinant protein production, where low copy number plasmids are often used and plasmid maintenance is important. The degree of repressor titration due to these plasmids was measured using the natural lactose operon in E. coli DH1 as a model. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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