Controlled-expression shuttle vector for pseudomonads based on the trpIBA genes of Pseudomonas putida

A cloning vector pPS7 (8.5 kb) for Pseudomonas was constructed from pBR322 and the Pseudomonas cryptic low-copy-number pMK1 plasmid. The vector confers resistance to kanamycin (Km) and tetracycline (Tc), contains the par locus of Pseudomonas plasmid pMT2 and a mob site. The new vector was used for construction of controlled-expression vector pPS10 (10.4kb) based on the trpIBA genes of Pseudomonas putida. This Km R vector contains the trpI gene, encoding activator protein and promoter of trpBA genes ( Pba), which are inducible by TrpI and indoleglycerol phosphate (InGP). InGP is an unstable compound, but it accumulates in trpE mutants grown in anthranilate (Anth)-supplemented medium. We show that expression of the Escherichia coli pheA gene, inserted into the pPS10 vector downstream from Pba, increases about 70-fold upon InGP accumulation.