Construction and characterization of F plasmid-based expression vectors

✍ Scribed by Kristala L. Jones; Jay D. Keasling

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 122 KB
• Volume: 59
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19980920)59:6<659::aid-bit1>3.0.co;2-e

✦ Synopsis

A low-copy expression vector has been constructed from a 9 Kbp region of the Escherichia coli F plasmid containing the oriV and oriS origins of replication. This plasmid carries the ␤-lactamase gene (Ap r ) and the araBAD promoter/araC regulator for arabinoseinducible gene expression. A derivative which carries a lacZ reporter gene was found to be stably maintained for at least 150 generations. A related multi-copy plasmid was stably maintained in arabinose-free medium, but no plasmid-bearing segregants remained after 60 generations when lacZ expression was induced. Induced expression resulted in 27% (multi-copy) and 12% (lowcopy) decreases in growth rate. The uninduced levels of ␤-galactosidase were 200 units (multi-copy) and 15 units (low-copy).