Genes in PHT plasmid encoding the initial degradation pathway of phthalate in Pseudomonas putida

摘要: The nucleotide sequence of a 7-kbp EcoRI fragment PHT plasmid in Pseudomonas putida encoding the enzymes initial step phthalate degradation (the Pht+ phenotype) revealed five open reading frames (ORFs), pht1 to pht5, with same orientation. protein deduced from showed 17.4% similarity amino acid glycerol-3-phosphate transporter Escherichia coli, that pht2 39.2% VanB (vanillate monooxygenase reductase) and pht3 20.8% VanA monooxygenase) sp. proteins encoded by pht4 pht5 no appreciable any database. Eight Pht− mutants Tn5 insertion pht1, one similar ORF were isolated. These pht1− pht5− mutants, two other induced UV irradiation strain testosteroni, examined complementation tests several segments pht feeding experiments phthalate, 4,5-dihydro-4,5-dihydroxyphthalate, 4,5-dihydroxyphthalate, protocatechuate. results these searches suggested encodes oxygenase reductase, oxygenase, 4,5-dihydro-4,5-dihydroxyphthalate dehydrogenase, 4,5-dihydroxyphthalate decarboxylase. Pht1 was function as positive regulator for expression genes or transporter. Three A : T rich regions, which may have promoter function, found upstream regions pht3, pht5. Northern blot analyses transcriptions are low level under relaxed control phthalate. pht4, might be