Disease relevance of pobA

• Identification of the transcriptional activator pobR and characterization of its role in the expression of pobA, the structural gene for p-hydroxybenzoate hydroxylase in Acinetobacter calcoaceticus [1].
• We have determined the nucleotide (nt) sequence of A. calcoaceticus pobA and performed a systematic comparison of the deduced amino acid (aa) sequence with that of the PobA enzyme from Pseudomonas fluorescens, for which the three-dimensional structure is known [2].
• Analysis of the pobA and pobR genes controlling expression of p-hydroxybenzoate hydroxylase in Azotobacter chroococcum [3].
• A fragment containing both pobA and pobR was cloned into pUC19 and p-hydroxybenzoate hydroxylase activity was induced in Escherichia coli by the addition of p-hydroxybenzoate [3].

High impact information on pobA

• The negative effect of protocatechuate on pobA expression is not based on a direct sensing of the metabolite by PobR, the specific regulator of pobA expression [4].
• Linkage analysis showed that hcaC is linked to pobA [5].
• These regulators may affect pobA expression by lowering the PcaK-mediated uptake of 4-hydroxybenzoate [6].
• A model is presented in which BenM and CatM prevent pobA expression indirectly during growth on benzoate [6].
• Growth on organic acids such as succinate, fumarate, and acetate allowed higher levels of pobA expression [6].

Chemical compound and disease context of pobA

• p-Hydroxybenzoate hydroxylase, the product of the pobA gene, gives rise to protocatechuate, which is metabolized by enzymes encoded by the pca operon in Acinetobacter calcoaceticus [7].
• Cloning of catBCIJFD genes for catechol degradation into chromosomal pobA and genetic stability of the recombinant Acinetobacter calcoaceticus [8].

Biological context of pobA

• The nucleotide sequence of pobR was determined, and the activator gene was shown to be transcribed divergently from pobA; the genes are separated by 134 DNA base pairs [1].
• A pobA-lacZ operon fusion was used to demonstrate that pobA expression in A. calcoaceticus is enhanced up to 400-fold by the inducer p-hydroxybenzoate [1].
• Downstream from hcaC and transcribed in the direction opposite the direction of pobA transcription are open reading frames designated hcaDEFG [5].
• The pobA and pobR genes are divergently transcribed and separated by 134 bp in the Acinetobacter calcoaceticus chromosome [9].
• A frame-shift mutation introduced into the pobR gene prevented expression of p-hydroxybenzoate hydroxylase, indicating that PobR is the protein required for transcription of pobA [3].

Associations of pobA with chemical compounds

• For this purpose, two model hybrid strains of A. calcoaceticus were created, in which a DNA fragment carrying catBCIJFD genes for catabolic degradation of catechol was inserted into pobA in opposite directions of each other, and their genetic stabilities were experimentally examined [8].

Other interactions of pobA

• Mutants selected on this medium contained the original mutation in pcaD and also carried spontaneous mutations in pobA [7].

Analytical, diagnostic and therapeutic context of pobA

• Sequence analysis of pobA revealed homology with other bacterial p-hydroxybenzoate hydroxylase enzymes [3].
• Surface plasmon resonance was used to determine the ability of mutant PobR proteins to bind to DNA in the pobA-pobR intergenic region [10].

References