Construction of a Pseudomonas aeruginosa random promoter library and identification of novel iron-regulated genes by high-throughput library screening

Abstract:

[Objective] Iron is an essential element for bacterial survival and pathogenesis. Using a random promoter library we screened for iron-responsive genes in P. aeruginosa genome. [Method] Plasmid pMS402 containing a promoterless luminescence reporter, LuxCDABE, was used as the vector to construct a P. aeruginosa random promoter library with a size of about 5700 clones. It enabled real-time, in vivo high-throughput gene expression profiling at genomic scale. [Results] Two previously reported iron-regulated genes were identified, and ten new iron- regulated genes were uncovered. The genes encoding dihydrolipoamide acetyltransferase, phosphogluconate dehydratase and Fe (Ⅲ) dicitrate transporter were found to be iron-regulated together with four function-unknown genes and three putative protein encoding genes. [Conclusion] These results provide a basis for elucidating the complex iron regulation network in P. aeruginosa and help our understanding of the roles of iron in bacterial physiology and pathogenesis. The random promoter library system also offers a useful tool in bacterial genomic studies.