title: Construction and characterization of F plasmid-based expression vectors.
abstract: 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 beta-lactamase gene (Apr) and the araBAD promoter/araC regulator for arabinose-inducible 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% (low-copy) decreases in growth rate. The uninduced levels of beta-galactosidase were 200 units (multi-copy) and 15 units (low-copy).
authors: Department of Chemical Engineering, University of California, Berkeley, California 94720-1462, USA.
authors: K L
authors: KL
authors: Jones
authors: J D
authors: JD
authors: Keasling
mesh_terms: D001089:Arabinose / Q000378:metabolism; D015139:Blotting, Southern; D002455:Cell Division; D003001:Cloning, Molecular / Q000379:methods*; D004926:Escherichia coli / Q000502:physiology; D005822:Genetic Vectors / Q000378:metabolism*; D008957:Models, Genetic; D010957:Plasmids / Q000378:metabolism*; D013997:Time Factors; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001089:Arabinose; D001616:beta-Galactosidase