RESUMO
OBJECTIVE: The aim was to investigate the regulator of phzA1B1C1D1E1F1(phzA1) operon in Pseudomonas aeruginosa. METHODS: Mutants affecting phzA1 expression in the presence of subinhibitory concentrations of tetracyclin were selected by screening a transposon mutagenesis library. The transposon insertion sites in the mutants were determined by arbitrary PCR and subsequent PCR product sequencing. RESULTS: We found two mutants affecting the phzA1 operon expression. The transposon insertion sites in these two mutants were at the promoter region of gene PA0487 encoding a probable molybdenum transport regulator. Some genes involved in quorum sensing were also down-regulated in the mutant. CONCLUSION: PA0487 was involved in regulating the expression of phzA1, possibly through the quorum sensing system.
