Characterization of the prephenate dehydrogenase-encoding gene, TYR1, from Saccharomyces cerevisiae

Mannhaupt, Gertrud; Stucka, Rolf; Pilz, Ursula; Schwarzlose, Christa; Feldmann, Horst

doi:10.1016/0378-1119(89)90422-8

Cited by 44 publications

(32 citation statements)

References 16 publications

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“…Surprisingly, the mutant strain showed auxotrophy for tyrosine but not for phenylalanine, with no residual chorismate mutase activity detectable in crude extracts of the disruption strain. One explanation, that the HARO7 gene might encode a bifunctional enzyme like a chorismate mutase-prephenate dehydrogenase activity (T protein), was ruled out because the HARO7 gene was not able to complement a tyr1 mutant strain of S. cerevisiae which lacks prephenate dehydrogenase activity (45). We conclude, therefore, that the HARO7-encoded activity is the only chorismate mutase enzyme in H. polymorpha and that no other redundant catalytic activity is encoded by a homologous gene.…”

Section: Discussionmentioning

confidence: 91%

HARO7 Encodes Chorismate Mutase of the Methylotrophic Yeast Hansenula polymorpha and Is Derepressed upon Methanol Utilization

et al. 2000

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The HARO7 gene of the methylotrophic, thermotolerant yeast Hansenula polymorpha was cloned by functional complementation. HARO7 encodes a monofunctional 280-amino-acid protein with chorismate mutase (EC 5.4.99.5) activity that catalyzes the conversion of chorismate to prephenate, a key step in the biosynthesis of aromatic amino acids. The HARO7 gene product shows strong similarities to primary sequences of known eukaryotic chorismate mutase enzymes. After homologous overexpression and purification of the 32-kDa protein, its kinetic parameters (k cat ‫؍‬ 319.1 s ؊1 , n H ‫؍‬ 1.56, [S] 0.5 ‫؍‬ 16.7 mM) as well as its allosteric regulatory properties were determined. Tryptophan acts as heterotropic positive effector; tyrosine is a negativeacting, heterotropic feedback inhibitor of enzyme activity. The influence of temperature on catalytic turnover and the thermal stability of the enzyme were determined and compared to features of the chorismate mutase enzyme of Saccharomyces cerevisiae. Using the Cre-loxP recombination system, we constructed mutant strains carrying a disrupted HARO7 gene that showed tyrosine auxotrophy and severe growth defects. The amount of the 0.9-kb HARO7 mRNA is independent of amino acid starvation conditions but increases twofold in the presence of methanol as the sole carbon source, implying a catabolite repression system acting on HARO7 expression.

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Section: Discussionmentioning

confidence: 91%

HARO7 Encodes Chorismate Mutase of the Methylotrophic Yeast Hansenula polymorpha and Is Derepressed upon Methanol Utilization

et al. 2000

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“…2). Because in plants the aromatic amino acid biosynthetic pathway takes place in plastids (Bickel et al, 1978), the coding sequence of yeast PDH, a cytosolic enzyme (Mannhaupt et al, 1989), was fused to an optimized plastid transit peptide (OTP), deriving from the transit peptide of the small subunit of Rubisco (Lebrun et al, 1992).…”

Section: Cloning and Expression Of The Recombinant Yeast Pdh In Eschementioning

confidence: 99%

“…The complete coding region of the yeast structural gene for PDH Tyr1, previously described by Mannhaupt et al (1989), was amplified by PCR from genomic DNA of the yeast W303␣ strain. The corresponding recombinant protein was overproduced in E. coli cells AT 2471 lacking endogenous PDH activity (Taylor and Trotter, 1967 As mentioned previously, HPP flux available for tocopherol biosynthesis is quite limited in plants.…”

Section: Cloning and Expression Of The Recombinant Yeast Pdh In Eschementioning

confidence: 99%

Engineering Plant Shikimate Pathway for Production of Tocotrienol and Improving Herbicide Resistance

et al. 2004

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Tocochromanols (tocopherols and tocotrienols), collectively known as vitamin E, are essential antioxidant components of both human and animal diets. Because of their potential health benefits, there is a considerable interest in plants with increased or customized vitamin E content. Here, we have explored a new strategy to reach this goal. In plants, phenylalanine is the precursor of a myriad of secondary compounds termed phenylpropanoids. In contrast, much less carbon is incorporated into tyrosine that provides p-hydroxyphenylpyruvate and homogentisate, the aromatic precursors of vitamin E. Therefore, we intended to increase the flux of these two compounds by deriving their synthesis directly at the level of prephenate. This was achieved by the expression of the yeast (Saccharomyces cerevisiae) prephenate dehydrogenase gene in tobacco (Nicotiana tabacum) plants that already overexpress the Arabidopsis p-hydroxyphenylpyruvate dioxygenase coding sequence. A massive accumulation of tocotrienols was observed in leaves. These molecules, which were undetectable in wild-type leaves, became the major forms of vitamin E in the leaves of the transgenic lines. An increased resistance of the transgenic plants toward the herbicidal p-hydroxyphenylpyruvate dioxygenase inhibitor diketonitril was also observed. This work demonstrates that the synthesis of p-hydroxyphenylpyruvate is a limiting step for the accumulation of vitamin E in plants.

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“…Prephenate can be used to synthesize phenylalanine in two steps: a dehydration forming phenylpyruvate, catalyzed by prephenate dehydratase in yeast (Maftahi et al, 1995;um00461 product in U. maydis) and then amination using either glutamate or alanine as amino group donors, in reactions catalyzed by aromatic amino acid aminotransferases I and II in yeast (Iraqui et al, 1998) and probably encoded by um01804 and um03538, respectively, in U. maydis. Tyrosine synthesis is identical, except that prephenate is oxidatively decarboxylated by the NADP-dependent prephenate dehydrogenase, the product of the yeast TYR1 (Mannhaupt et al, 1989) and likely of um04182.…”

Section: Aromatic Amino Acids: Phenylalanine Tryptophan and Tyrosinementioning

confidence: 99%

A genome-based analysis of amino acid metabolism in the biotrophic plant pathogen Ustilago maydis

McCann

Snetselaar

2008

Fungal Genetics and Biology

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Characterization of the prephenate dehydrogenase-encoding gene, TYR1, from Saccharomyces cerevisiae

Cited by 44 publications

References 16 publications

HARO7 Encodes Chorismate Mutase of the Methylotrophic Yeast Hansenula polymorpha and Is Derepressed upon Methanol Utilization

HARO7 Encodes Chorismate Mutase of the Methylotrophic Yeast Hansenula polymorpha and Is Derepressed upon Methanol Utilization

Engineering Plant Shikimate Pathway for Production of Tocotrienol and Improving Herbicide Resistance

A genome-based analysis of amino acid metabolism in the biotrophic plant pathogen Ustilago maydis

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