| Primary Identifier | IPR036263 | Type | Homologous_superfamily |
| Short Name | Chorismate_II_sf |
| description | Chorismate mutase (CM) is a regulatory enzyme () required forbiosynthesis of the aromatic amino acids phenylalanine and tyrosine. CMcatalyzes the Claisen rearrangement of chorismate to prephenate, which cansubsequently be converted to precursors of either L-Phe or L-Tyr. Inbifunctional enzymes the CM domain can be fused to a prephenate dehydratase(P-protein for Phe biosynthesis), to a prephenatedehydrogenase (T-protein, for Tyr biosynthesis), or to3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase.Besides these prokaryotic bifunctional enzymes, monofunctional CMs occur inprokaryotes as well as in fungi, plants and nematode worms []. The sequence of monofunctional chorismate mutase aligns well with the N-terminal part of P-proteins [].The type II or AroQ class of CM has an all-helical 3Dstructure, represented by the CM domain of the bifunctional Escherichia coliP-protein. This type is named after the Enterobacteragglomerans monofunctional CM encoded by the aroQ gene []. All CM domainsfrom bifunctional enzymes as well as most monofunctional CMs belong to thisclass, including archaeal CM.Eukaryotic CM from plants and fungi form a separate subclass of AroQ,represented by the Baker's yeast allosteric CM. These enzymes show onlypartial sequence similarity to the prokaryotic CMs due to insertions ofregulatory domains, but the helix-bundle topology and catalytic residues areconserved and the 3D structure of the E. coli CM dimer resembles a yeast CMmonomer [, , ]. The E. coli P-protein CM domain consists of3 helices and lacks allosteric regulation. The yeast CM has evolved by geneduplication and dimerization and each monomer has 12 helices. Yeast CM isallosterically activated by Trp and inhibited by Tyr []. |
