According to the literature, members of the structural domains which comprise this superfamily correspond to a conserved component in the protein ORF1 of the long interspersed nuclear element 1 (LINE-1 or L1) retrotransposon. This domain is designated RRM, which stands for RNA recognition motif, and is involved in RNA binding. Cooperation between this RRM domain and the C-terminal domain is required to achieve this, despite the fact that this two domains do not contact each other PMID:21822284.