InterPro: IPR008240 Chorismate mutase, periplasmic

Chorismate mutase (CM; EC:5.4.99.5) catalyses the reaction at the branch point of the biosynthetic pathway leading to the three aromatic amino acids, phenylalanine, tryptophan and tyrosine (chorismic acid is the last common intermediate, and CM leads to the L-phenylalanine/L-tyrosine branch). It is part of the shikimate pathway, which is present only in bacteria, fungi and plants. Members of this family contain a chorismate mutase domain of the AroQ class (Prokaryotic type) that has an all-helical structure.

The three types of CM are AroQ class, Prokaryotic type (e.g., IPR008239 amongst others); AroQ class, Eukaryotic type (IPR008238); and AroH class (IPR008243). They fall into two structural folds (AroQ class and AroH class) which are completely unrelated [1]. The two types of the AroQ structural class (the Escherichia coli CM dimer and the yeast CM monomer) can be structurally superimposed, and the topology of the four-helix bundle forming the active site is conserved [1].

Periplasmic chorismate mutases form a subclass of the AroQ class, and are twice the size of cytoplasmic AroQ proteins due to a carboxy-terminal domain of unknown function [2]. This C-terminal domain is so far unique to members of this group.

For additional information please see [3, 4, 5, 6].