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At least 19 recordsLinked to original sources
PubMed1989

Origin of p-aminobenzoic acid from chorismic rather than iso-chorismic acid in Enterobacter aerogenes and Streptomyces species.

Enzyme extracts from Enterobacter aerogenes (62-1), Streptomyces aminophilus, and Streptomyces coelicolor were used to investigate the biosynthesis of p-aminobenzoic acid. The enzyme preparations from E. aerogenes and S. aminophilus contained both p-aminobenzoate synthase and iso-chorismate synthase activity, and were able to convert both chorismic and iso-chorismic acid to p-aminobenzoic acid. The apparent KM for chorismic acid was, however, significantly lower than that for iso-chorismic acid, while the Vmax was identical for both substrates in both enzyme systems. The enzyme preparations from S. coelicolor did not contain iso-chorismate synthase activity and p-aminobenzoic acid synthesis took place in this system from chorismic acid only. It is concluded that iso-chorismic acid is not an obligatory intermediate in p-aminobenzoic acid biosynthesis in these organisms.

4-Aminobenzoic Acid↗
PubMed1990

Chorismic acid, a key metabolite in modification of tRNA.

Chorismic acid is the common precursor for the biosynthesis of the three aromatic amino acids as well as for four vitamins. Mutants of Escherichia coli defective in any of the genes involved in the synthesis of chorismic acid are also unable to synthesize uridine 5-oxyacetic acid (cmo5U) and its methyl ester (mcmo5U). Both modified nucleosides are normally present in the wobble position of some tRNA species. Mutants defective in any of the specific pathways leading to phenylalanine, tyrosine, tryptophan, folate, enterochelin, ubiquinone, and menaquinone have normal levels of cmo5U and mcmo5U in their tRNA. The presence of shikimic acid in the growth medium restores the ability of an aroD mutant to synthesize cmo5U, while O-succinylbenzoate, which is an early intermediate in the synthesis of menaquinone, does not. Thus, chorismic acid is a key metabolite in the synthesis of these two modified nucleosides in tRNA. The absence of chorismic acid blocks the formation of cmo5U and mcmo5U at the first step, which might be the formation of 5-hydroxyuridine. This results in an unmodified U in the wobble position of tRNA(1Val) and in most of the tRNAs normally containing cmo5U and mcmo5U. Since cmo5U and mcmo5U are synthesized under anaerobic conditions, the formation of these nucleosides does not require molecular oxygen. One of the carbon atoms of the side chain, --O--CH2--COOH, originates from the methyl group of methionine. The other carbon atom does not originate directly from the C-1 pool, from the carboxyl group methionine, or from bicarbonate. This metabolic link between intermediary metabolism and translation also exists for another member of the family Enterobacteriaceae, Salmonella typhimurium, as well as for the distantly related gram-positive organism Bacillus subtilis.

Bacillus subtilis↗
PubMed1996

Small scale biosynthesis and purification of gram quantities of chorismic acid.

This paper details improvements in the biosynthetic method of purification of chorismic acid using Klebsiella pneumoniae 62-1. New growth and accumulation conditions yielded 4 L of accumulation medium containing approximately 0.5 g/L of chorismate from 2 L of bacterial growth. Improvements in the handling and extraction procedures produced yields of approximately 2 g of 75 to 90% chorismic acid. A new recrystallization procedure yielded chorismic acid 97% pure by weight (using epsilon 275 = 2630 M-1 cm-1), and 99.8% pure by enzymatic conversion. These results represent a three- to five-fold increase in yield over average published values.

Chorismic Acid↗
PubMed1985

Incorporation of chorismic acid and 4-aminobenzoic acid into the 4-hydroxyaniline moiety of N-(gamma-L-glutamyl)-4-hydroxyaniline in Agaricus bisporus.

Agaricus bisporus contains the unique aniline derivative, N-(gamma-L-glutamyl)-4-hydroxyaniline. 14C-labelled chorismic acid was quantitatively incorporated into the 4-hydroxyaniline moiety of this aniline derivative, whereas 14C-labelled prephenic acid and anthranilic acid were not incorporated into 4-hydroxyaniline. These observations indicate the branch point of the biosynthetic route of 4-hydroxyaniline in the shikimic acid pathway to be chorismic acid. Moreover, 4-aminobenzoic acid proved to be an effective precursor of 4-hydroxyaniline.

4-Aminobenzoic Acid↗
PubMedDate not supplied

Strobilurin N and two metabolites related to chorismic acid from the fruit bodies of Mycena crocata (Agaricales).

Strobilurin N (1), a new member of the strobilurin family of antibiotics, has been isolated from the toadstool Mycena crocata, together with dehydrochorismic acid lactone (5) and 3-[1-carboxyvinyl)oxy]benzoic acid (6), which are closely related to chorismic acid (10). Their structures were determined mainly by 1H and 13C NMR spectroscopy. Interestingly, strobilurin N is the first strobilurin without antifungal activity.

Agaricales↗
PubMed1976

Biosynthesis of chloramphenicol in Streptomyces sp. 3022a. Identification of p-amino-L-phenylalanine as a product from the action of arylamine synthetase on chorismic acid.

Products obtained from the action of arylamine synthetase on [G-14C]chorismic acid were fractionated by gel filtration and ion exchange column chromatography to yield a partially purified radioactive component with an arylamine function. From its ultraviolet absorption spectrum and thin-layer chromatographic behaviour the product was considered to be p-aminophenylalanine and the identification was confirmed by co-crystallization with an authentic specimen. Specific deamination of the product with L-amino-acid oxidase indicated that it was the L-epimer. These results strengthen previous evidence that arylamine synthetase is at a branch point in the shikimic acid pathway, specifically diverting intermediates to the synthesis of chloramphenicol.

Amino Acid Oxidoreductases↗
PubMed1975

Biosynthesis of phenylalanine, tyrosine, 3-(3-carbocyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine in higher plants. Examples of the transformation possibilities for chorismic acid.

14C-labelled shikimic acid and double labelled shikimic acid tritiated stereospicifically at C-6 are incorporated into 3-(3-carboxyphenyl) alanine, 3-(3-carboxy-4-hydroxyphenyl) alanine, phenylalanine, and tyrosine in Reseda lutea L., Reseda odorata L., Iris x Hollandica cv. Prof. Blauw, and Iris x hollandica cv. Wedgwood. The experiments with 14C-labelled shikimic acid confirm that the aromatic carboxyl groups and rings in 3-(3-carboxyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine derive from the carbocyl group and ring in shikimic acid whereas the experiments with double labelled shikimic acid demonstrate that the pro-6S-hydrogen atom is retained and the pro-6R-hydrogen atom lost in the biosynthesis of 3-(3-carboxyphenyl) alanine, phenylalanine, and tyrosine in the plants used. 3H was located in the ortho-position in the aromatic rings of phenylalanine and tyrosine but in a position para to the alanine side chain of 3- (3-carboxyphenly) alanine. No 3H was found in 3- (3-carboxy-4-hydroxyphenyl) alanine. This supports a derivation of the last two compounds from chorismic acid via isochorismic acid, isoprephenic acid, and 3'-carboxyphenylpyruvic acid and 3'-carbocy-4'-hydroxyphenylphruvic acid. The 3H/14C ratio in 3-(3-carboxyphenyl) alanine was found higher than in the precursor used. This isotope effect must operate by competition between the pathways from isoprephenic acid to 3'-carbocyphenylpyruvic acid and to 3'-carbocy-4'- hydroxyphenylpyruvic acic. The proposed biosynthetic pathways for the two carboxy-substituted amino acids are in agreement with their distribution patterns in the plant kingdom and suggest that they may derive from minor changes of enzymes involved in the general pathways of aromatic biosynthesis.

Amino Acids↗
PubMed1991

Biosynthesis of isochorismate in Klebsiella pneumoniae: origin of O-2.

The shikimate metabolites are key precursors to a large number of natural products, including aromatic amino acids. Chorismic acid is an important branch point in the biosynthetic pathway to aromatic amino acids. Chorismic acid is also unique among natural products since it is the only compound known to undergo an enzymatic Claisen rearrangement. A metabolite of chorismic acid, isochorismic acid, first observed in Aerobacter aerogenes differs in its chemical structure by the location of the hydroxyl group and the double bonds. Isochorismic acid is a precursor to a growing number of shikimate-derived metabolites. Isochorismic acid has also been postulated to be an intermediate of m-carboxyaromatic amino acids, implying another enzymatic Claisen rearrangement. In this publication, we have isolated isochorismate synthase and found that on lyophilization the enzyme is stable for at least 6 months at -20 degrees C. Incubation of chorismate with this preparation in water enriched with 18O led to incorporation of one atom of 18O as proven from the fast atom bombardment mass spectra of the HPLC purified derived isochorismate.

Chorismic Acid↗