Transformation of Saccharomyces cerevisiae with a cDNA encoding a sterol C-methyltransferase from Arabidopsis thaliana results in the synthesis of 24-ethyl sterols.
Using an EST-cDNA probe, a full-length cDNA (411) sequence of 1411 bp was isolated from A. thaliana. This sequence contained features typical of methyltransferases in general and in particular showed 38% identity with ERG6, a S. cerevisiae gene which encodes the zymosterol-C-24-methyltransferase. A yeast vector containing this ORF (4118-pYeDP60) was used to transform a wild type S. cerevisiae which accumulates predominantly ergosterol, a 24-methyl sterol as well as a mutant erg6 null mutant accumulating principally zymosterol, a sterol non-alkylated at C-24. In both cases, several 24-ethyl- and 24-ethylidene sterols were synthetized indicating that the 4118 cDNA encodes a plant sterol C-methyltransferase able to perform two sequential methylations of the sterol side chain.
Husselstein
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T
Institut de Biologie Moléculaire des Plantes, Département de Biologie Cellulaire et Moléculaire, Institut de Botanique, Strasbourg, France.
Gachotte
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Desprez
T
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Bard
M
M
Benveniste
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P
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D015342:DNA Probes; D018076:DNA, Complementary; D018744:DNA, Plant / Q000302:isolation & purification; D004926:Escherichia coli; D015723:Gene Library; D017343:Genes, Plant; D008780:Methyltransferases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013261:Sterols / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity; D014170:Transformation, Genetic
D015342:DNA Probes; D018076:DNA, Complementary; D018744:DNA, Plant; D011994:Recombinant Proteins; D013261:Sterols; D008780:Methyltransferases; C022670:delta 24-sterol methyltransferase