Fig. (1) Construction of the Tn5P transposon. A) The Tn5 from pEVS170 contains an erythromycin resistance gene and an origin of replication (blue arrow and box) within the Tn5 ends (red rectangles). pEVS170 was modified to contain an outward-facing, LacI-repressible/IPTG-inducible promoter, PA1/34 (green arrow) [1]. (B) The PA1/34 promoter region (italics) contains two LacI binding sites (bold). The binding of LacI to these sites hinders access to the -35 and -10 sites (green), thus repressing transcription. The Tn5 end (red) contains a start codon (underlined).