Improved single and multicopy lac-based cloning vectors for protein and operon fusions

摘要: We describe several new vectors for the construction of operon and protein fusions to Escherichia coli lacZ gene. In vitro constructions utilize multicopy plasmids containing suitable cloning sites located between upstream transcription terminators downstream lac segments whose genes retain or lack translational start signals. Single-copy lambda prophage versions constructs can be made genetically, without in manipulation. The vectors, both single multicopy, are improved that they have very low levels background gene expression, which makes possible easy detection accurate quantitation weak transcriptional These were developed analysis expression IS10's transposase gene, is transcribed less than, once per generation, transcripts translated on average than each. Both also used select mutations affecting fusion isolated single-copy crossed genetically back onto further analysis.