This superfamily includes the dimerisation domain found in members of the Dicer or Dicer-like (DCL) proteins, involved in microRNA (miRNA) or small interference RNA (siRNA) pathway, an evolutionarily conserved mechanism for gene silencing using double-stranded RNA (dsRNA) molecules. The dimerisation domain is essential for the activity of Dicer PMID:16424907,PMID:17666393. The N-terminal alpha helix of this domain is in a different orientation to that found in canonical dsRNA-binding domains. This results in a change of charge distribution at the potential dsRNA-binding surface and in the N- and C-termini of the domain being in close proximity PMID:20106953. This domain has weak dsRNA-binding activity. It mediates heterodimerisation of Dicer proteins with their respective protein partners PMID:20106953.

PFAM:PF03368,INTERPRO:IPR005034