| Type: | Family | Name: | Prephenate dehydrogenase/arogenate dehydrogenase |
| Description: | Members of this group catalyse a step in tyrosine biosynthesis in the shikimate pathway, which is present only in bacteria, fungi, and plants. They contain both a prephenate dehydrogenase domain (PDH) and a regulatory domain. Prephenate dehydrogenase (PDH) () catalyses oxidative decarboxylation of prephenate to 4-hydroxyphenylpyruvate. Many of the proteins containing this domain are able to use the alternative intermediates of tyrosine biosynthesis, prephenate or L-arogenate, as substrates, and thus contain both prephenate dehydrogenase and arogenate dehydrogenase activities (arogenate dehydrogenase, catalyses oxidative decarboxylation of arogenate into tyrosine). Therefore, they are also called cyclohexadienyl dehydrogenases. The C-terminal domain of these proteins is predicted to play a regulatory role. It has a distant but unmistakable similarity to the ferredoxin-fold anticodon-binding domain found in some phenylalanyl-tRNA synthetases (detected by PSI-BLAST). There is evidence that the dehydrogenase activity of chorismate mutase-prephenate dehydrogenase, the allosteric enzyme of the tyrosine biosynthetic pathway in Escherichia coli, is inhibited by tRNA. Related prephenate dehydrogenases from yeast and plants (e.g., S46037) do not have this domain and instead have a different domain at the C terminus.For additional information please see [, ]. | Short Name: | Prep_DH/arog_DH |
