Schematic diagram of the XbaI-SacI cassette of pTS inserted into pPROBE-NT. Properties of plasmid pPROBE-NT containing the pGreenTir gfp cassette have been described elsewhere (24, 25). Abbreviations: T1, rrnB rRNA T1 terminator; PtbuA1, promoter of the tbu operon and the upstream activating sequences; RBS, ribosome binding site; PnptII, neomycin phosphotransferase promoter; tbuT, transcriptional activator gene. Arrows indicate the direction of transcription. The diagram is not drawn to scale.