Molecular and biochemical characterization of an Arabidopsis thaliana arogenate dehydrogenase with two highly similar and active protein domains.
The present study reports the first molecular characterization of a plant arogenate dehydrogenase, the enzyme that catalyses the transformation of arogenate into tyrosine. The structure of the Arabidopsis thaliana tyrA gene is very peculiar since it encodes two highly similar, and putatively active, protein domains. PCR analyses confirmed the existence of a transcript encoding the two protein domains. The complete coding sequence and sequences corresponding to the two separate domains were independently cloned into Escherichia coli mutant AT 2471 lacking prephenate dehydrogenase activity. Our results revealed that the three recombinant enzymes are active. They all exhibit a high specificity toward arogenate and NADP, and have very similar kinetic properties.
Rippert
Pascal
P
Laboratoire Mixte CNRS/INRA/Aventis CropScience (UMR 1932), Lyon, France.
Matringe
Michel
M
D000595:Amino Acid Sequence; D000600:Amino Acids, Dicarboxylic / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D003001:Cloning, Molecular; D053138:Cyclohexenes; D004926:Escherichia coli / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D017343:Genes, Plant / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D011303:Prephenate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D000600:Amino Acids, Dicarboxylic; D029681:Arabidopsis Proteins; D053138:Cyclohexenes; D011994:Recombinant Proteins; D014443:Tyrosine; C015478:pretyrosine; D011303:Prephenate Dehydrogenase; C027017:cyclohexadienyl dehydrogenase