A plasmid vector for simultaneous generation of lacZ protein fusions and npt-II operon fusions in vivo

Abstract

We have constructed a plasmid vector, pHLH1, that contains lacZ and npt-II genes flanked by ends of bacteriophage Mu. These sequences can be integrated into Escherichia coli chromosome by the Mu transposition system. The lacZ gene, deleted for its transcription and translation initiation signals, was positioned next to the 117 bp terminal fragment for the s end of Mu. The npt-II gene, deleted for its transcriptional signals, was positioned distal to lacZ in the same orientation. Transposition of this sequence to a target gene can create simultaneously a protein fusion to lacZ and an operon fusion to npt-II. To demonstrate the use of this vector, we isolated lacZnpt-II+ fusions to ompC. These fusions exhibited the expected phenotypes and regulational properties of ompC fusions.