| Type: | Family | Name: | Arogenate dehydrogenase 2 |
| Description: | Chloroplastic arogenate dehydrogenase 2 belongs to the prephenate dehydrogenase (PDH) domain superfamily (). Members of this group catalyse a step in tyrosine biosynthesis in the shikimate pathway, which is present only in bacteria, archaea, fungi, and plants []. Many of the PDH enzymes are able to use the alternative intermediates of tyrosine biosynthesis, prephenate or L-arogenate, as substrates, having both prephenate dehydrogenase and arogenate dehydrogenase activities, and are sometimes collectively called cyclohexadienyl dehydrogenases [, ]. Arogenate dehydrogenase 2 has a weak prephenate dehydrogenase activity [].Arabidopsis thaliana has two arogenate dehydrogenase isoforms, tyrAAT1 and tyrAAT2. TyrAAT1 is unusual in that it contains a duplication of the PDH domain. Both copies of the PDH domain have arogenate dehydrogenase activity with similar biochemical characteristics []. The experimentally studied plant enzymes are NADP-dependent arogenate dehydrogenases that are very sensitive toward feedback inhibition by the product of the reaction (tyrosine); in fact, they exhibit a higher affinity for tyrosine than for their arogenate substrate []. Interestingly, these proteins do not seem to have any additional domain that can be suggested to be responsible for this regulation. | Short Name: | Arogenate_DH_2 |
