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Johnathan A Napier - One of the best experts on this subject based on the ideXlab platform.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    Abstract A cDNA encoding a C20 Δ8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Δ8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Δ8-desaturase with the Isochrysis galbana Δ9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Δ8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    A cDNA encoding a C20 Delta8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Delta8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Delta8-desaturase with the Isochrysis galbana Delta9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Delta8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

Olga Sayanova - One of the best experts on this subject based on the ideXlab platform.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    Abstract A cDNA encoding a C20 Δ8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Δ8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Δ8-desaturase with the Isochrysis galbana Δ9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Δ8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    A cDNA encoding a C20 Delta8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Delta8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Delta8-desaturase with the Isochrysis galbana Delta9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Delta8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

Teruhiro Takabe - One of the best experts on this subject based on the ideXlab platform.

  • isolation and functional characterization of n methyltransferases that catalyze betaine synthesis from glycine in a halotolerant Photosynthetic Organism aphanothece halophytica
    Journal of Biological Chemistry, 2003
    Co-Authors: Rungaroon Waditee, Yoshito Tanaka, Kenji Aoki, Takashi Hibino, Hiroshi Jikuya, Jun Takano, Tetsuko Takabe, Teruhiro Takabe
    Abstract:

    Abstract Glycine betaine (N,N,N-trimethylglycine) is an important osmoprotectant and is synthesized in response to abiotic stresses. Although almost all known biosynthetic pathways of betaine are two-step oxidation of choline, here we isolated twoN-methyltransferase genes from a halotolerant cyanobacterium Aphanothece halophytica. One of gene products (ORF1) catalyzed the methylation reactions of glycine and sarcosine with S-adenosylmethionine acting as the methyl donor. The other one (ORF2) specifically catalyzed the methylation of dimethylglycine to betaine. Both enzymes are active as monomers. Betaine, a final product, did not show the feed back inhibition for the methyltransferases even in the presence of 2 m. A reaction product, S-adenosyl homocysteine, inhibited the methylation reactions with relatively low affinities. The co-expressing of two enzymes in Escherichia coli increased the betaine level and enhanced the growth rates. Immunoblot analysis revealed that the accumulation levels of both enzymes in A. halophytica cells increased with increasing the salinity. These results indicate thatA. halophytica cells synthesize betaine from glycine by a three-step methylation. The changes of amino acids Arg-169 to Lys or Glu in ORF1 and Pro-171 to Gln and/or Met-172 to Arg in ORF2 significantly decreased V max and increasedK m for methyl acceptors (glycine, sarcosine, and dimethylglycine) but modestly affected K m forS-adenosylmethionine, indicating the importance of these amino acids for the binding of methyl acceptors. Physiological and functional properties of methyltransferases were discussed.

  • isolation and functional characterization ofn methyltransferases that catalyze betaine synthesis from glycine in a halotolerant Photosynthetic Organism aphanothece halophytica
    Journal of Biological Chemistry, 2003
    Co-Authors: Rungaroon Waditee, Yoshito Tanaka, Kenji Aoki, Takashi Hibino, Hiroshi Jikuya, Jun Takano, Tetsuko Takabe, Teruhiro Takabe
    Abstract:

    Abstract Glycine betaine (N,N,N-trimethylglycine) is an important osmoprotectant and is synthesized in response to abiotic stresses. Although almost all known biosynthetic pathways of betaine are two-step oxidation of choline, here we isolated twoN-methyltransferase genes from a halotolerant cyanobacterium Aphanothece halophytica. One of gene products (ORF1) catalyzed the methylation reactions of glycine and sarcosine with S-adenosylmethionine acting as the methyl donor. The other one (ORF2) specifically catalyzed the methylation of dimethylglycine to betaine. Both enzymes are active as monomers. Betaine, a final product, did not show the feed back inhibition for the methyltransferases even in the presence of 2 m. A reaction product, S-adenosyl homocysteine, inhibited the methylation reactions with relatively low affinities. The co-expressing of two enzymes in Escherichia coli increased the betaine level and enhanced the growth rates. Immunoblot analysis revealed that the accumulation levels of both enzymes in A. halophytica cells increased with increasing the salinity. These results indicate thatA. halophytica cells synthesize betaine from glycine by a three-step methylation. The changes of amino acids Arg-169 to Lys or Glu in ORF1 and Pro-171 to Gln and/or Met-172 to Arg in ORF2 significantly decreased V max and increasedK m for methyl acceptors (glycine, sarcosine, and dimethylglycine) but modestly affected K m forS-adenosylmethionine, indicating the importance of these amino acids for the binding of methyl acceptors. Physiological and functional properties of methyltransferases were discussed.

Richard P Haslam - One of the best experts on this subject based on the ideXlab platform.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    Abstract A cDNA encoding a C20 Δ8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Δ8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Δ8-desaturase with the Isochrysis galbana Δ9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Δ8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    A cDNA encoding a C20 Delta8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Delta8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Delta8-desaturase with the Isochrysis galbana Delta9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Delta8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

Colin M Lazarus - One of the best experts on this subject based on the ideXlab platform.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    Abstract A cDNA encoding a C20 Δ8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Δ8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Δ8-desaturase with the Isochrysis galbana Δ9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Δ8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.

  • the alternative pathway c20 δ8 desaturase from the non Photosynthetic Organism acanthamoeba castellanii is an atypical cytochrome b5 fusion desaturase
    FEBS Letters, 2006
    Co-Authors: Olga Sayanova, Richard P Haslam, Colin M Lazarus, Johnathan A Napier
    Abstract:

    A cDNA encoding a C20 Delta8-desaturase was isolated from the free-living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Delta8-desaturase showed similarity to other microsomal front-end desaturases, but the N-terminal domain contained a variant form of the conserved heme-binding motif in which H-P-G-G is replaced by H-P-A-G. Co-expression of the A. castellani Delta8-desaturase with the Isochrysis galbana Delta9-elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl-CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl-CoA pool. This is the first report of an alternative pathway C20 Delta8-desaturase from a non-Photosynthetic Organism, and also the first report of a front-end desaturase lacking the canonical cytochrome b5 domain.