The structure of the representative domain for this superfamily maps to a Pfam domain which belongs to a family named glutamate cysteine ligase. However, it maps only to a segment of this Pfam domain and therefore, in the absence of any information on this representative domain, the term subdomain has been introduced to design this superfamily.

This nomenclature is consistent with UniProt-SwissProt, EC and GO entries, all of which highlight the role of this superfamily in glutamate-cysteine ligation.