Cupin, RmlC-type <p>RmlC (dTDP (deoxythimodone diphosphates)-4-dehydrorhamnose 3,5-epimerase; <db_xref db="EC" dbkey="5.1.3.13"/>) is a dTDP-sugar isomerase enzyme involved in the synthesis of L-rhamnose, a saccharide required for the virulence of some pathogenic bacteria [<cite idref="PUB00009949"/>]. RmlC is a dimer, each monomer being formed from two beta-sheets arranged in a beta-sandwich, where the substrate-binding site is located between the two sheets of both monomers.</p><p>Other protein families contain domains that share this fold, including glucose-6-phosphate isomerase (<db_xref db="EC" dbkey="5.3.1.9"/>); germin, a metal-binding protein with oxalate oxidase and superoxide dismutases activities [<cite idref="PUB00014173"/>]; auxin-binding protein [<cite idref="PUB00014174"/>]; seed storage protein 7S [<cite idref="PUB00014175"/>]; acireductone dioxygenase [<cite idref="PUB00014176"/>]; as well as three proteins that have metal-binding sites similar to that of germine, namely quercetin 2,3-dioxygenase (<db_xref db="EC" dbkey="1.13.11.24"/>) [<cite idref="PUB00014177"/>], phosphomannose isomerase (<db_xref db="EC" dbkey="5.3.1.8"/>) [<cite idref="PUB00003929"/>] and homogentisate dioxygenase (<db_xref db="EC" dbkey="1.13.11.5"/>) [<cite idref="PUB00009903"/>], the last three sharing a 2-domain fold with storage protein 7s.</p>