<p>Shikimate kinase (<db_xref db="EC" dbkey="2.7.1.71"/>) catalyses the fifth step in the shikimate pathway of aromatic amino acids biosynthesis. It converts shikimate to shikimate 3-phosphate (3-phosphoshikimate). This part of the pathway leads to the biosynthesis of chorismate, the precursor of aromatic amino acids, folates, ubiquinones, and other aromatic compounds. The shikimate pathway links metabolism of carbohydrates to biosynthesis of the aromatic amino acids phenylalanine, tyrosine, tryptophan and their derivatives in microorganisms and plants [<cite idref="PUB00014334"/>]. In a sequence of seven enzymatic reactions, D-erythrose 4-phosphate (E4P), an intermediate of the pentose phosphate pathway and phosphoenol pyruvate (PEP), a glycolytic intermediate, are converted to chorismate. The shikimate pathway is present in bacteria, archaea, fungi and plants. The absence of the shikimate pathway in animals makes it an attractive target for non-toxic herbicides, antimicrobial and antifungal agents.</p><p>Shikimate kinase enzymes present an example of convergent evolution via enzyme recruitment from an unrelated group. This group represents shikimate kinases of the archaeal type. Members have no sequence similarity with the typical form of shikimate kinase (<db_xref db="PIRSF" dbkey="PIRSF000702"/>, <db_xref db="INTERPRO" dbkey="IPR000623"/>) found in bacteria and eukaryotes, but are instead distantly related to homoserine kinases, which belong to the GHMP kinase domain superfamily (GHMP = galactose, homoserine, mevalonate, and phosphomevalonate) [<cite idref="PUB00013836"/>]. All known non-archaeal shikimate kinases (the typical form) belong to the non-homologous, structurally unrelated nucleoside monophosphate (NMP) kinase domain superfamily [<cite idref="PUB00003386"/>].</p><p>Nomenclature note: the name AroK is used for non-homologous shikimate kinases of both the archaeal and bacterial types.</p> Shikimate kinase, archaea