Disease relevance of p-Methylbenzoic acid

• Transcription of the TOL plasmid toluate catabolic pathway operon of Pseudomonas putida is determined by a pair of co-ordinately and positively regulated overlapping promoters [1].
• This hybrid encodes toluate oxygenase and all meta cleavage pathway enzymes, and it enables P. putida mt-2 and Escherichia coli K-12 cells to grow on m-toluate as sole carbon source [2].
• The novel enzyme 4-methyl-2-enelactone methyl-isomerase was detected in, and purified to electrophoretic homogeneity from, p-toluate-grown cells of Rhodococcus rhodocrous N75, a nocardioform actinomycete [3].
• Alcaligenes eutrophus wild-type strain 345 metabolizes m- and p-toluate via a catechol meta-cleavage pathway [4].
• The cbdABC sequences show significant homology to benABC, which encode benzoate 1,2-dioxygenase from Acinetobacter calcoaceticus (52% identity at the deduced amino acid level), and to xylXYZ, which encode toluate 1,2-dioxygenase from Pseudomonas putida mt-2 (51% amino acid identity) [5].

High impact information on p-Methylbenzoic acid

• In the xylT mutants, all the meta-cleavage enzymes were induced by p-toluate with the exception of catechol 2,3-dioxygenase whose activity was 1% of the p-toluate-induced activity in wild-type cells [6].
• We further show that p-toluic acid and the bidentate transition state analogue, Kojic acid, displace chloride from the oxidized active site, whereas the monodentate substrate analogue, p-nitrophenol, forms a ternary complex with the enzyme and the chloride ion [7].
• Using this approach, bilayer permeability coefficients of p-toluic acid and p-hydroxymethyl benzoic acid were determined to be 1.1 +/- 0.2 cm s-1 and (1.6 +/- 0.4) x 10(-3) cm s-1, respectively [8].
• When a C23O gene (e.g., xylE) is introduced into this strain, the transformants cannot generally grow on p-toluate because 4-methylcatechol, a metabolite of p-toluate, is a substrate as well as a suicide inhibitor of C23O [9].
• The ptsN gene of Pseudomonas putida encodes IIA(Ntr), a protein of the phosphoenol pyruvate:sugar phosphotransferase (PTS) system which is required for the C source inhibition of the sigma(54)-dependent promoter Pu of the TOL (toluate degradation) plasmid pWW0 [10].

Chemical compound and disease context of p-Methylbenzoic acid

• Of a 49-strain collection of Pseudomonas stutzeri species, 11 isolates were able to degrade naphthalene and 1 isolate was able to use m- and p-toluate as sole carbon and energy sources [11].
• Pairs of mutant plasmids, consisting of one Tn1000 derivative and one nitrosoguanidine-induced derivative, were used for complementation analysis of toluate dioxygenase in Escherichia coli recA bacteria, in which the formation of 2-hydroxymuconic semialdehyde from benzoate was examined [12].
• Dioxygenation of substituted benzoic acids by whole cells of 3-chlorobenzoate-utilizing Pseudomonas sp. B 13, benzoate-induced cells of Alcaligenes eutrophus B 9 and toluate-grown cells of Pseudomonas putida mt-2 was examined [13].

Biological context of p-Methylbenzoic acid

• Analysis of pTN81 and pTN9 allowed estimation of the region of the gene cluster for benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, as well as the region required for toluate oxygenase activity [14].
• The toluate catabolic operon carried by the TOL plasmid pWW0 of Pseudomonas putida is positively regulated by the benzoate-responsive XylS protein which, when activated, stimulates transcription from the operon promoter Pm [15].
• Four cistrons for toluate 1,2-dioxygenase were thus identified [12].
• Genetic analysis of a relaxed substrate specificity aromatic ring dioxygenase, toluate 1,2-dioxygenase, encoded by TOL plasmid pWW0 of Pseudomonas putida [12].
• Neither the methanogens nor the acetogenic bacteria appeared to be directly involved in the biotransformation of p-toluic acid under either atmosphere [16].

Associations of p-Methylbenzoic acid with other chemical compounds

• A 9.5-kilobase fragment, derived from the TOL segment of pTN2 deoxyribonucleic acid, carried the xyl genes D, E, G, and F, which encode toluate oxygenase, catechol 2,3-oxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, and 2-hydroxymuconic semialdehyde hydrolase, respectively [17].
• Adenosylcobalamin-mediated methyl transfer by toluate cis-dihydrodiol dehydrogenase of the TOL plasmid pWW0 [18].
• The fluxes of p-toluic acid and seven alpha-methylene-substituted analogs have been determined as a function of pH across planar egg lecithin/decane bilayers to construct a set of well-isolated polar functional group contributions to the free energy of transfer from water to the bilayer transport barrier domain [19].
• Bacteria that grow on p-xylene, p-toluic acid, and terephthalic acid (TPA) were isolated from a wastewater bioreactor that is used to treat a waste stream that contains all three of these compounds [20].
• Under the CO2 atmosphere, biotransformation of p-toluic acid involved sulfate-reducing bacteria, while under N2/H2, both sulfate-reducing bacteria and other eubacteria were involved [16].

Gene context of p-Methylbenzoic acid

• The electron transfer component of benzoate dioxygenase, encoded by benC, and the corresponding protein of the toluate 1,2-dioxygenase, encoded by xylZ, were each found to have an N-terminal region which resembled chloroplast-type ferredoxins and a C-terminal region which resembled several oxidoreductases [21].
• No activities of the TOL plasmid encoded toluate dioxygenase and catechol 2,3-dioxygenase were detectable in strain CG220 [22].
• DNA fragments containing the xylD and xylL genes of TOL plasmid pWW0 -161 of Pseudomonas putida, which code for the catabolic enzymes toluate 1,2-dioxygenase and dihydrodihydroxybenzoic acid dehydrogenase, respectively, and the nahG gene of the NAH plasmid NAH7 , which codes for salicylate hydroxylase, were cloned in pBR322 vector plasmid [23].
• Southern hybridizations demonstrated that DNA encoding the benzoate dioxygenase structural genes showed homology to DNA encoding toluate dioxygenase from the TOL plasmid pWW0, but benR did not show homology to xylS [24].
• Nonlinear regression analyses of flux-pH profiles using a model which accounts for unstirred layer effects yielded membrane permeability coefficients (PRX) that varied from 1.1 cm/s for p-toluic acid to 4.1 x 10(-5) cm/s for the alpha-carbamoyl-p-toluic acid [19].

References