Maize glutathione-dependent formaldehyde dehydrogenase cDNA: a novel plant gene of detoxification.
We have previously shown that intact plants and cultured plant cells can metabolize and detoxify formaldehyde through the action of a glutathione-dependent formaldehyde dehydrogenase (FDH), followed by C-1 metabolism of the initial metabolite (formic acid). The cloning and heterologous expression of a cDNA for the glutathione-dependent formaldehyde dehydrogenase from Zea mays L. is now described. The functional expression of the maize cDNA in Escherichia coli proved that the cloned enzyme catalyses the NAD(+)- and glutathione (GSH)-dependent oxidation of formaldehyde. The deduced amino acid sequence of 41 kDa was on average 65% identical with class III alcohol dehydrogenase from animals and less than 60% identical with conventional plant alcohol dehydrogenases (ADH) utilizing ethanol. Genomic analysis suggested the existence of a single gene for this cDNA. Phylogenetic analysis supports the convergent evolution of ethanol-consuming ADHs in animals and plants from formaldehyde-detoxifying ancestors. The high structural conservation of present-day glutathione-dependent FDH in microorganisms, plants and animals is consistent with a universal importance of these detoxifying enzymes.
Fliegmann
J
J
GSF-Forschungszentrum für Umwelt und Gesundheit, Institut für Biochemische Pflanzenpathologie, Oberschleissheim, Germany.
Sandermann
H
H
D000426:Alcohol Dehydrogenase / Q000302:isolation & purification; D000445:Aldehyde Oxidoreductases / Q000235:genetics* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D019143:Evolution, Molecular; D005557:Formaldehyde / Q000378:metabolism*; D017343:Genes, Plant; D005978:Glutathione / Q000378:metabolism; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D003313:Zea mays / Q000201:enzymology / Q000235:genetics*
D018076:DNA, Complementary; D009243:NAD; D005557:Formaldehyde; D000426:Alcohol Dehydrogenase; C020145:formaldehyde dehydrogenase (glutathione); D000445:Aldehyde Oxidoreductases; D005978:Glutathione