Organization and activation of the late promoters of phiCTX, a cytotoxin-converting phage from Pseudomonas aeruginosa

Molecular Genetics and Genomics : MGG
Jörg AlberF Lutz

Abstract

The late genes of the temperate phage of Pseudomonas aeruginosa are organized in an analogous fashion to the corresponding transcription units of the Escherichia coli P2 and P2-like phages. Sequence analysis of four putative late promoter regions, PP(phiCTX), PO(phiCTX), PV(phiCTX) and PF(phiCTX), reveals no similarity to sigma(70)-type promoters or promoter consensus sequences found in Pseudomonas, indicating the apparent need for a phage-encoded protein to control the expression of phiCTX late genes. To elucidate the mode of expression of the late genes, we fused the putative late promoter regions to the promoterless lacZalpha gene, which encodes the N-terminal part of beta-galactosidase as a reporter enzyme, in the promoter-probe vector pME4510. The candidate transactivator gene orf34 was cloned into expression vector pHA10, to generate the plasmid pHA34. The two recombinant plasmids were introduced together into E. coli XL1-Blue and P. aeruginosa PAO1S-Lac. Our results demonstrate that in phiCTX three late promoters (PP(phiCTX), PO(phiCTX), and PF(phiCTX)) are activated upon induction by IPTG in PAO1S-Lac carrying the cloned promoters and pHA34. Deletions and base-pair substitutions obtained by PCR-mediated mutagenesis demo...Continue Reading

Citations

May 11, 2007·Research in Microbiology·Anders S Nilsson, Elisabeth Haggård-Ljungquist
Sep 29, 2015·Genome Biology and Evolution·Maarten G K GhequireRené De Mot

❮ Previous
Next ❯

Related Concepts

Related Feeds

Bacteriophage: Phage Therapy

Phage therapy uses bacterial viruses (bacteriophages) to treat bacterial infections and is widely being recognized as an alternative to antibiotics. Here is the latest research.