title: Cloning and sequencing show that 4-hydroxybenzoate hydroxylase (PobA) is required for uptake of 4-hydroxybenzoate in Rhizobium leguminosarum.
abstract: Mutants of Rhizobium leguminosarum bv. viciae MNF300 and R. leguminosarum bv. trifolii WU95 unable to accumulate 4-hydroxybenzoate lack 4-hydroxybenzoate hydroxylase. The capacity of these mutants to take up and grow on 4-hydroxybenzoate was restored by a 2.0 kb EcoRI-PstI DNA fragment. This contained only one ORF which had over 60% DNA sequence similarity with the structural gene for 4-hydroxybenzoate hydroxylase (pobA) from Pseudomonas spp. and Acinetobacter. Reported effects of metabolic inhibitors and substrate analogues on the apparent uptake of 4-hydroxybenzoate have now been shown to be due to their direct effect on 4-hydroxybenzoate hydroxylase. We propose that uptake of 4-hydroxybenzoate is via a metabolic 'drag' mechanism dependent on the activity of the pobA gene product.
authors.affiliation: School of Biological and Environmental Sciences, Murdoch University, Western Australia.
authors.forename: C M
authors.initials: CM
authors.lastname: Wong
authors.forename: M J
authors.initials: MJ
authors.lastname: Dilworth
authors.forename: A R
authors.initials: AR
authors.lastname: Glenn
mesh_terms: D015109:4-Hydroxybenzoate-3-Monooxygenase / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015342:DNA Probes; D004789:Enzyme Activation; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D010226:Parabens / Q000378:metabolism*; D010957:Plasmids; D016961:Rhizobium leguminosarum / Q000201:enzymology* / Q000235:genetics; D017421:Sequence Analysis
chemical_list: D015342:DNA Probes; D010226:Parabens; D015109:4-Hydroxybenzoate-3-Monooxygenase; C038193:4-hydroxybenzoic acid