The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Carole L Linster - One of the best experts on this subject based on the ideXlab platform.
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a novel gdp d glucose phosphorylase involved in quality control of the Nucleoside Diphosphate Sugar pool in caenorhabditis elegans and mammals
Journal of Biological Chemistry, 2011Co-Authors: Lital N Adler, Tara A Gomez, Steven Clarke, Carole L LinsterAbstract:The plant VTC2 gene encodes GDP-l-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 homolog genes (C15orf58 and C10F3.4, respectively) and found that the purified proteins also display GDP-hexose phosphorylase activity. However, as opposed to the plant enzyme, the major reaction catalyzed by these enzymes is the phosphorolysis of GDP-d-glucose to GDP and d-glucose 1-phosphate. We detected activities with similar substrate specificity in worm and mouse tissue extracts. The highest expression of GDP-d-glucose phosphorylase was found in the nervous and male reproductive systems. A C. elegans C10F3.4 deletion strain was found to totally lack GDP-d-glucose phosphorylase activity; this activity was also found to be decreased in human HEK293T cells transfected with siRNAs against the human C15orf58 gene. These observations confirm the identification of the worm C10F3.4 and the human C15orf58 gene expression products as the GDP-d-glucose phosphorylases of these organisms. Significantly, we found an accumulation of GDP-d-glucose in the C10F3.4 mutant worms, suggesting that the GDP-d-glucose phosphorylase may function to remove GDP-d-glucose formed by GDP-d-mannose pyrophosphorylase, an enzyme that has previously been shown to lack specificity for its physiological d-mannose 1-phosphate substrate. We propose that such removal may prevent the misincorporation of glucosyl residues for mannosyl residues into the glycoconjugates of worms and mammals.
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a novel gdp d glucose phosphorylase involved in quality control of the Nucleoside Diphosphate Sugar pool in
2011Co-Authors: Lital N Adler, Tara A Gomez, Steven Clarke, Carole L LinsterAbstract:The plant VTC2 gene encodes GDP-L-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 homolog genes (C15orf58 and C10F3.4, respectively) and found that the purified proteins also display GDP-hexose phosphorylase activity. However, as opposed to the plant enzyme, the major reaction catalyzed by these enzymes is the phosphorolysis of GDP-D-glucose to GDP and D-glucose 1-phosphate. We detected activities with similar substrate specificity in worm and mouse tissue extracts. The highest expression of GDP-D-glucose phosphorylase was found in the nervous and male reproductive systems. A C. elegans C10F3.4 deletion strain was found to totally lack GDP-D-glucose phosphorylase activity; this activity was also found to be decreased in human HEK293T cells transfected with siRNAs against the human C15orf58 gene. These observations confirm the identification of the worm C10F3.4 and the human C15orf58 gene expression products as the GDP-D-glucose phosphorylases of these organisms. Significantly, we found an accumulation of GDP-D-glucose in the C10F3.4 mutant worms, suggesting that the GDP-D-glucose phosphorylase may function to remove GDP-D-glucose formed by GDP-D-mannose pyrophosphorylase, an enzyme that has previously been shown to lack specificity for its physiological D-mannose 1-phosphate substrate. We propose that such removal may prevent the misincorporation of glucosyl residues for mannosyl residues into the glycoconjugates of worms and mammals.
David Aragao - One of the best experts on this subject based on the ideXlab platform.
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the complex of sphingomonas elodea atcc 31461 glucose 1 phosphate uridylyltransferase with glucose 1 phosphate reveals a novel quaternary structure unique among Nucleoside Diphosphate Sugar pyrophosphorylase members
Journal of Bacteriology, 2007Co-Authors: David Aragao, Arsenio M Fialho, A R Marques, Edward P Mitchell, Isabel Sacorreia, Carlos FrazaoAbstract:Gellan gum is a widely used commercial material, available in many different forms. Its economic importance has led to studies into the biosynthesis of exopolysaccharide gellan gum, which is industrially prepared in high yields using Sphingomonas elodea ATCC 31461. Glucose-1-phosphate uridylyltransferase mediates the reversible conversion of glucose-1-phosphate and UTP into UDP-glucose and pyrophosphate, which is a key step in the biosynthetic pathway of gellan gums. Here we present the X-ray crystal structure of the glucose-1-phosphate uridylyltransferase from S. elodea. The S. elodea enzyme shares strong monomeric similarity with glucose-1-phosphate thymidylyltransferase, several structures of which are known, although the quaternary structures of the active enzymes are rather different. A detailed comparison between S. elodea glucose-1-phosphate uridylyltransferase and available thymidylyltransferases is described and shows remarkable structural similarities, despite the low sequence identities between the two divergent groups of proteins.
Sandra B Gabelli - One of the best experts on this subject based on the ideXlab platform.
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structural and enzymatic characterization of a Nucleoside Diphosphate Sugar hydrolase from bdellovibrio bacteriovorus
PLOS ONE, 2015Co-Authors: Andres H De La Pena, Silvia A Pineiro, Mario L Amzel, Allison Suarez, Krisna C Duongly, Andrew Schoeffield, Mario A Pizarrodupuy, Melissa Zarr, Sandra B GabelliAbstract:Given the broad range of substrates hydrolyzed by Nudix (Nucleoside Diphosphate linked to X) enzymes, identification of sequence and structural elements that correctly predict a Nudix substrate or characterize a family is key to correctly annotate the myriad of Nudix enzymes. Here, we present the structure determination and characterization of Bd3179 –- a Nudix hydrolase from Bdellovibrio bacteriovorus–that we show localized in the periplasmic space of this obligate Gram-negative predator. We demonstrate that the enzyme is a Nucleoside Diphosphate Sugar hydrolase (NDPSase) and has a high degree of sequence and structural similarity to a canonical ADP-ribose hydrolase and to a Nucleoside Diphosphate Sugar hydrolase (1.4 and 1.3 A Cα RMSD respectively). Examination of the structural elements conserved in both types of enzymes confirms that an aspartate-X-lysine motif on the C-terminal helix of the α-β-α NDPSase fold differentiates NDPSases from ADPRases.
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Bd-NDPSase wild type and E140Q substrate specificity.
2015Co-Authors: Andres H De La Pena, Silvia A Pineiro, Mario L Amzel, Allison Suarez, Andrew Schoeffield, Melissa Zarr, Mario A. Pizarro-dupuy, Krisna C. Duong-ly, Sandra B GabelliAbstract:A) Wild type enzyme (gray bars) exhibited preference for Nucleoside Diphosphate Sugar (NDPS). E140Q mutant (red bars) were catalytically inactive. B) Initial rates of GDPM hydrolysis for the wild type and E140Q mutant were fit by nonlinear least squares to the Michaelis-Menten equation (solid lines) to determine kcat (5.2 (ms)-1) and Km (0.3 mM). Standard deviations of triplicate measurements are shown by the shaded bars for the wild type (gray shade) and mutant (red shade).
Lital N Adler - One of the best experts on this subject based on the ideXlab platform.
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a novel gdp d glucose phosphorylase involved in quality control of the Nucleoside Diphosphate Sugar pool in caenorhabditis elegans and mammals
Journal of Biological Chemistry, 2011Co-Authors: Lital N Adler, Tara A Gomez, Steven Clarke, Carole L LinsterAbstract:The plant VTC2 gene encodes GDP-l-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 homolog genes (C15orf58 and C10F3.4, respectively) and found that the purified proteins also display GDP-hexose phosphorylase activity. However, as opposed to the plant enzyme, the major reaction catalyzed by these enzymes is the phosphorolysis of GDP-d-glucose to GDP and d-glucose 1-phosphate. We detected activities with similar substrate specificity in worm and mouse tissue extracts. The highest expression of GDP-d-glucose phosphorylase was found in the nervous and male reproductive systems. A C. elegans C10F3.4 deletion strain was found to totally lack GDP-d-glucose phosphorylase activity; this activity was also found to be decreased in human HEK293T cells transfected with siRNAs against the human C15orf58 gene. These observations confirm the identification of the worm C10F3.4 and the human C15orf58 gene expression products as the GDP-d-glucose phosphorylases of these organisms. Significantly, we found an accumulation of GDP-d-glucose in the C10F3.4 mutant worms, suggesting that the GDP-d-glucose phosphorylase may function to remove GDP-d-glucose formed by GDP-d-mannose pyrophosphorylase, an enzyme that has previously been shown to lack specificity for its physiological d-mannose 1-phosphate substrate. We propose that such removal may prevent the misincorporation of glucosyl residues for mannosyl residues into the glycoconjugates of worms and mammals.
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a novel gdp d glucose phosphorylase involved in quality control of the Nucleoside Diphosphate Sugar pool in
2011Co-Authors: Lital N Adler, Tara A Gomez, Steven Clarke, Carole L LinsterAbstract:The plant VTC2 gene encodes GDP-L-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 homolog genes (C15orf58 and C10F3.4, respectively) and found that the purified proteins also display GDP-hexose phosphorylase activity. However, as opposed to the plant enzyme, the major reaction catalyzed by these enzymes is the phosphorolysis of GDP-D-glucose to GDP and D-glucose 1-phosphate. We detected activities with similar substrate specificity in worm and mouse tissue extracts. The highest expression of GDP-D-glucose phosphorylase was found in the nervous and male reproductive systems. A C. elegans C10F3.4 deletion strain was found to totally lack GDP-D-glucose phosphorylase activity; this activity was also found to be decreased in human HEK293T cells transfected with siRNAs against the human C15orf58 gene. These observations confirm the identification of the worm C10F3.4 and the human C15orf58 gene expression products as the GDP-D-glucose phosphorylases of these organisms. Significantly, we found an accumulation of GDP-D-glucose in the C10F3.4 mutant worms, suggesting that the GDP-D-glucose phosphorylase may function to remove GDP-D-glucose formed by GDP-D-mannose pyrophosphorylase, an enzyme that has previously been shown to lack specificity for its physiological D-mannose 1-phosphate substrate. We propose that such removal may prevent the misincorporation of glucosyl residues for mannosyl residues into the glycoconjugates of worms and mammals.
Andres H De La Pena - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Structural and Enzymatic Characterization of a Nucleoside Diphosphate Sugar Hydrolase from Bdellovibrio bacteriovorus
2016Co-Authors: Andres H De La Pena, Mario L Amzel, Allison Suarez, Andrew Schoeffield, Melissa Zarr, Krisna C. Duong-ly¤a, Mario A. Pizarro-dupuy, Silvia A. Pineiro¤b, B. GabelliAbstract:Given the broad range of substrates hydrolyzed by Nudix (Nucleoside Diphosphate linked to X) enzymes, identification of sequence and structural elements that correctly predict a Nudix substrate or characterize a family is key to correctly annotate the myriad of Nudix enzymes. Here, we present the structure determination and characterization of Bd3179 –- a Nudix hydrolase from Bdellovibrio bacteriovorus–that we show localized in the periplasmic space of this obligate Gram-negative predator. We demonstrate that the enzyme is a nucle-oside Diphosphate Sugar hydrolase (NDPSase) and has a high degree of sequence and structural similarity to a canonical ADP-ribose hydrolase and to a Nucleoside Diphosphate Sugar hydrolase (1.4 and 1.3 Å Cα RMSD respectively). Examination of the structural ele-ments conserved in both types of enzymes confirms that an aspartate-X-lysine motif on th
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structural and enzymatic characterization of a Nucleoside Diphosphate Sugar hydrolase from bdellovibrio bacteriovorus
PLOS ONE, 2015Co-Authors: Andres H De La Pena, Silvia A Pineiro, Mario L Amzel, Allison Suarez, Krisna C Duongly, Andrew Schoeffield, Mario A Pizarrodupuy, Melissa Zarr, Sandra B GabelliAbstract:Given the broad range of substrates hydrolyzed by Nudix (Nucleoside Diphosphate linked to X) enzymes, identification of sequence and structural elements that correctly predict a Nudix substrate or characterize a family is key to correctly annotate the myriad of Nudix enzymes. Here, we present the structure determination and characterization of Bd3179 –- a Nudix hydrolase from Bdellovibrio bacteriovorus–that we show localized in the periplasmic space of this obligate Gram-negative predator. We demonstrate that the enzyme is a Nucleoside Diphosphate Sugar hydrolase (NDPSase) and has a high degree of sequence and structural similarity to a canonical ADP-ribose hydrolase and to a Nucleoside Diphosphate Sugar hydrolase (1.4 and 1.3 A Cα RMSD respectively). Examination of the structural elements conserved in both types of enzymes confirms that an aspartate-X-lysine motif on the C-terminal helix of the α-β-α NDPSase fold differentiates NDPSases from ADPRases.
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Bd-NDPSase wild type and E140Q substrate specificity.
2015Co-Authors: Andres H De La Pena, Silvia A Pineiro, Mario L Amzel, Allison Suarez, Andrew Schoeffield, Melissa Zarr, Mario A. Pizarro-dupuy, Krisna C. Duong-ly, Sandra B GabelliAbstract:A) Wild type enzyme (gray bars) exhibited preference for Nucleoside Diphosphate Sugar (NDPS). E140Q mutant (red bars) were catalytically inactive. B) Initial rates of GDPM hydrolysis for the wild type and E140Q mutant were fit by nonlinear least squares to the Michaelis-Menten equation (solid lines) to determine kcat (5.2 (ms)-1) and Km (0.3 mM). Standard deviations of triplicate measurements are shown by the shaded bars for the wild type (gray shade) and mutant (red shade).
