A simple method for studying lacZ fusions in lacZ+ Escherichia coli hosts

Escherichia coli-mycobacteria shuttle vectors for operon and gene fusions to lacZ: the pJEM series.

A series of Escherichia coli-mycobacteria shuttle plasmids for the isolation and study of gene regulatory sequences was constructed. These pJEM vectors contain an efficient transcription terminator and multiple cloning sites and allow either operon or gene fusions to lacZ. By constructing operon fusions with pJEM15, we assessed various previously characterized mycobacterial promoters in the fas...

Isolation of fla-lacZ fusions in Escherichia coli K-12: most fusions result in soluble beta-galactosidase.

A series of fusions of flagellar genes to the lacZ gene was generated by insertion of Mu dII301 (Apr lac) bacteriophage into the genome of Escherichia coli. The beta-galactosidase activity in each resulting mutant was measured, and the location of the activity in the membrane, periplasmic, or cytoplasmic fraction of the cell was determined. There were three classes of mutants: those which had b...

Fusions of bacteriophage P22 late genes to the Escherichia coli lacZ gene.

The late genes of bacteriophage P22 were fused to lacZ to study their differential expression from the late operon transcript. No instances of posttranscriptional regulation were uncovered, thus supporting the model that the late genes are expressed, by and large, in fixed ratios based on their translational efficiency and message stability.

LacZ-promoter fusions: the effect of growth.

Regulation of HIS4-lacZ fusions in Saccharomyces cerevisiae.

The beginning of the Saccharomyces cerevisiae HIS4 gene has been fused to the structural gene for Escherichia coli beta-galactosidase. This construction, which contains HIS4 DNA from -732 to +30 relative to the translation initiation codon, has been integrated into the yeast genome at two chromosomal locations, HIS4 and URA3. At both locations, this 762-base-pair stretch of DNA is sufficient fo...