Molecular cloning of Mu d(bla lacZ) transcriptional and translational fusions.

The vector pBW2 was made to selectively clone chimeric plasmids with chromosomal Mu d(bla lacZ) transcriptional or translational fusions. It was tetracycline resistant and had the carboxyl-terminal end of bla distal to its PstI site. Because ligation of PstI-digested chromosomal DNA of a Mu d(bla lacZ) insertion with pBW2 restored bla, ampicillin-resistant chimeric plasmids were selectable. These plasmids had the Mu d bla amino terminus and simultaneously acquired other Mu d sequences including lacZ, the chromosomal fusion joint, and the DNA adjacent to the nearest chromosomal PstI site. The plasmid pBW2 was useful in the molecular cloning of several psi and pho::lacZ(Mu d) fusions, as well as chromosomal genes located near Mu d insertions.