Abstract.
The role of the Escherichia coli lacY gene product (the lactose permease) in the induction of isopropyl-β-D-thiogalactopyranoside (IPTG) inducible promoters was studied in E. coli and P. fluorescens. This was done by comparing strains containing a lacIPOZYA chromosomal insert with newly constructed strains containing inserts without the lacY gene (lacIPOZ). The lactose operon inserts were introduced as single-copy chromosomal inserts to eliminate differences in expression caused by differences in copy number. Comparison between the two types of inserts showed that the lactose permease was essential to allow growth on lactose by both bacteria and that the lactose permease plays an important role in transporting the inducer IPTG across the membrane of P. fluorescens. The use of a functional lactose permease allows expression of β-galactosidase to increase more than fivefold from a wild-type lac promoter in P. fluorescens SS1001. We suggest that an increase in the rate of protein synthesis from lac-type promoters could be enhanced if an active lactose permease is present as well.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 29 October 1997 / Accepted: 8 December 1997
Rights and permissions
About this article
Cite this article
Hansen, L., Knudsen, S. & Sørensen, S. The Effect of the lacY Gene on the Induction of IPTG Inducible Promoters, Studied in Escherichia coli and Pseudomonas fluorescens . Curr Microbiol 36, 341–347 (1998). https://doi.org/10.1007/s002849900320
Issue Date:
DOI: https://doi.org/10.1007/s002849900320