<p>This domain is found in homoserine kinases (<db_xref db="EC" dbkey="2.7.1.39"/>), galactokinases (<db_xref db="EC" dbkey="2.7.1.6"/>) and mevalonate kinases (<db_xref db="EC" dbkey="2.7.1.36"/>). These kinases make up the GHMP kinase superfamily of ATP-dependent enzymes [<cite idref="PUB00015675"/>]. These enzymes are involved in the biosynthesis of isoprenes and amino acids as well as in carbohydrate metabolism. The C-terminal domain of homoserine kinase has a central alpha-beta plait fold and an insertion of four helices, which, together with the N-terminal fold, create a novel nucleotide binding fold [<cite idref="PUB00015644"/>].</p>