Localization, Purification, and Characterization of Shikimate Oxidoreductase-Dehydroquinate Hydrolyase from Stroma of Spinach Chloroplasts

Fiedler, Erich; Schultz, Gernot

doi:10.1104/pp.79.1.212

Cited by 51 publications

(34 citation statements)

References 14 publications

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“…Similar to spinach (Fiedler and Schultz, 1985) and other species (Schmidt et al, 1991), the SORase of pea roots is localized in the plastid stroma. No evidence for a cytosolic isoenzyme was obtained in our studies.…”

Section: 07mentioning

confidence: 74%

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The Metabolism of Quinate in Pea Roots (Purification and Partial Characterization of a Quinate Hydrolyase)

1995

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QA and SK are compounds that often occur in relatively high concentrations in green and nongreen tissues of herbaceous (Yoshida et al., 1975) and woody angiosperms (Boudet, 1973). For example, in the spring, high amounts of QA are formed in developing coniferous needles (2-10% of dry weight) in the course of photosynthetic C02 fixation (Dittrich and Kandler, 1971). This QA pool is metabolized during the lignification process in the summer. QA is also a precursor for chlorogenic acids and is converted into other secondary products like protocatechuic acid (Haslam, 1974). Although QA is formed by a QA:NAD(P)+ oxidoreductase from DHQ, an intermediate in the SK pathway (Bentley, 1990), its involvement in AAA biosynthesis is not clear. 14C-labeled QA is incorporated into free and proteinbound AAA in different herbaceous species and members of the Rosaceae (Weinstein et al., 1959(Weinstein et al., , 1961 and in mung bean (Minamikawa et al., 1969). However, the actual enzymatic steps for channeling QA into the SK pathway are not known.In pea (Pisum sativum L.) epicotyls, an irreversible conversion of QA into SK has been found (Tazaki et al., 1974), whereas the reaction appears to be reversible in mung bean (Minamikawa et al

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Section: 07mentioning

confidence: 74%

“…SKNADP+ oxidoreductase (EC 1.1.1.25) and DHQase (EC 4.2.1.10) activities were measured according to Fiedler and Schultz (1985).…”

Section: Measurements Of Enzyme Activitiesmentioning

confidence: 99%

The Metabolism of Quinate in Pea Roots (Purification and Partial Characterization of a Quinate Hydrolyase)

1995

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“…DAHP3 synthase ( 11) and chorismate mutase (31), whereas in others, e.g. shikimate oxidoreductase/dehydroquinate hydrolyase (9), the enzymes appear to be restricted to the chloroplast. In a previous report it was demonstrated that the synthesis of aromatic amino acids in spinach chloroplasts is controlled by light (19).…”

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confidence: 99%

Shikimate Kinase from Spinach Chloroplasts

Schmidt¹,

Danneel²,

Schultz³

et al. 1990

Plant Physiol.

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Shikimate kinase was purified to near homogenity from spinach Spinacia oleracea L. chloroplasts and found to consist of a single 31 kilodalton polypeptide. The purified enzyme was unstable, but could be stabilized by a variety of added proteins, including oxidized and reduced thioredoxins. Whereas the isolated enzyme was stimulated by mono-and dithiol reagents, the enzyme in intact chloroplasts was unaffected by added thiols and showed only minor response to dark/light transitions. These results indicate that the previously reported stimulation of shikimate kinase activity by reduced thioredoxins is due to enzyme stabilization rather than to activation. In the current study, the purified enzyme was inhibited by added ADP and showed a strong response to energy charge. When intact chloroplasts were incubated in the dark in presence of shikimate, phosphoenolpyruvate and a source of ATP (dihydroxyacetone phosphate or ATP itself under appropriate conditions), aromatic amino acids were formed: phenylalanine and tyrosine. The data indicate that energy charge plays a role in regulating shikimate kinase, thereby controlling the shikimate paway. An unidentified enzyme of the latter part of the pathway, leading from shikimate-3-phosphate to phenylalanine, appears to be activated by light.

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“…In plants, these two enzyme activities actually constitute a bifunctional protein with probably the same channelling function (Polley, 1978;Fiedler & Schultz, 1985;Mousdale et al, 1987). Mono Q anion-exchange chromatography of (Fig.…”

Section: Quinate and Shikimate Metabolismmentioning

confidence: 99%

Purification and characterization of a dual function 3-dehydroquinate dehydratase from Amycolatopsis methanolica

Euverink

Hessels

Vrijbloed

et al. 1992

Journal of General Microbiology

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Studies on hydroaromatic metabolism in the actinomycete Amycofafopsis methanofica revealed that the organism grows rapidly on quinate (but not on shikimate) as sole carbon-and energy source. Quinate is initially converted into the shikimate pathway intermediate 3-dehydroquinate by an inducible NAD+-dependent quinate/shikimate dehydrogenase. 3-Dehydroquinate dehydratase subsequently converts 3-dehydroquinate into 3-dehydroshikimate, which is used partly for the biosynthesis of aromatic amino acids, and is partly catabolized via protocatechuate and the P-ketoadipate pathway. Enzyme studies and analysis of mutants clearly showed that the single 3-dehydroquinate dehydratase present in A. methanofica has a dual function, the first example of a 3-dehydroquinate dehydratase enzyme involved in both the catabolism of quinate and the biosynthesis of aromatic amino acids. This enzyme was purified over 1700-fold to homogeneity. Its further characterization indicated that it is a Type I1 3-dehydroquinate dehydratase, a thermostable enzyme with a large oligomeric structure (native M, 135 x lo3) and a subunit M, of 12 x lo3. Characterization of aromatic amino acid auxotrophic mutants of A. methanofica suggested that genes encoding 3-dehydroquinate synthase and 3-dehydroquinate dehydratase are genetically linked but their transcription results in the synthesis of two separate proteins.

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Localization, Purification, and Characterization of Shikimate Oxidoreductase-Dehydroquinate Hydrolyase from Stroma of Spinach Chloroplasts

Cited by 51 publications

References 14 publications

The Metabolism of Quinate in Pea Roots (Purification and Partial Characterization of a Quinate Hydrolyase)

The Metabolism of Quinate in Pea Roots (Purification and Partial Characterization of a Quinate Hydrolyase)

Shikimate Kinase from Spinach Chloroplasts

Purification and characterization of a dual function 3-dehydroquinate dehydratase from Amycolatopsis methanolica

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