Laboratory of Molecular Biology, State University of Ghent, Ledeganckstraat 35, B-9000 Ghent Belgium
Abstract:
A family of plasmid cloning vectors has been constructed that make use of the leftward promoter () of phage λ to provide for efficient expression of cloned genes in Escherichia coli. The promoter activity of is fully repressed at low temperature by a thermolabile repressor product of the gene, and can be activated by heat induction. Examples are given (β-lactamse, tryptophan synthetase A) where, under optimal conditions, between 30 and 40% of the total protein synthesis is directed by the cloned gene under control.