Identification of genes involved in the 4-aminobenzenesulfote degradation pathway of hyrogenophaga sp.PBC via transposon mutagenesis

• Main Authors: Han, Ming Gan, Ibrahim, Zaharah, Shahir, Shafinaz, Yahya, Adibah
• Format: Article
• Published: Oxford University Press 2011
• Subjects: QH Natural history
• Online Access: http://eprints.utm.my/id/eprint/44970/; http://dx.doi.org/10.1111/j.1574-6968.2011.02245.x
• Institution: Universiti Teknologi Malaysia

Genes involved in the 4-aminobenzenesulfonate (4-ABS) degradation pathway of Hydrogenophaga sp. PBC were identified using transposon mutagenesis. The screening of 10 000 mutants for incomplete 4-ABS biotransformation identified four mutants with single transposon insertion. Genes with insertions that impaired the ability to utilize 4-ABS for growth included (1) 4-sulfocatechol 1,2-dioxygenase b-subunit (pcaH2) and 3-sulfomuconate cycloisomerase involved in the modified b-ketoadipate pathway; (2) 4-aminobenzenesulfonate 3,4-dioxy- genase component (sadA) involved in aromatic ring hydroxylation; and (3) transposase gene homolog with a putative cis-diol dehydrogenase gene located downstream. The pcaH2 mutant strain accumulated brown metabolite during growth on 4-ABS which was identified as 4-sulfocatechol through thin layer chromatography and HPLC analyses. Supplementation of w ild-type sadA gene in trans restored the 4-ABS degradation ability of the sadA mutant, thus supporting the annotation of its disrupted gene.