<p> The family of proteins found in this family include the characterised LysX from <taxon tax_id="274">Thermus thermophilus</taxon> [<cite idref="PUB00015489"/>] which is part of a well-organised lysine biosynthesis gene cluster [<cite idref="PUB00015490"/>]. LysX is believed to carry out an ATP-dependent acylation of the amino group of alpha-aminoadipate in the prokaryotic version of the fungal AAA lysine biosynthesis pathway. No species having a sequence in this family contains the elements of the more common diaminopimelate lysine biosythesis pathway, and none has been shown to be a lysine auxotroph. These sequences have mainly recieved the name of the related enzyme, "ribosomal protein S6 modification protein RimK". RimK has been characterised in <taxon tax_id="562">Escherichia coli</taxon>, and acts by ATP-dependent condensation of S6 with glutamate residues [<cite idref="PUB00015491"/>].</p>