Fig 1.
Cosmid complementation strategy for identification of FabH-type activity in P. aeruginosa PAO1. The E. coli strain TMY19 has a chloramphenicol cassette (camR) inserted within fabH (b1091) and needs l-Ara supplementation to induce expression of the PBAD-regulated S. enterica fabH ortholog (inserted within the d-glucitol phosphotransferase operon) in order to sustain wild-type growth rates. The operon is transcriptionally silent under standard culture conditions in the absence of d-glucitol (52). A sheared library of wild-type P. aeruginosa PAO1 genomic DNA was ligated into the pWEB cosmid vector, packaged, and transduced by phage into E. coli TMY19. Transductants were directly selected on unsupplemented LB agar to identify cosmids (pTMYcos1 to pTMYcos17) that complement depletion of FabH.