This domain is found at the C-terminus of Ribonuclease J proteins. Its function is unknown, but deletion of this domain causes dissociation to monomers [2].

1: Molecular basis for the recognition and cleavage of RNA by the bifunctional 5'-3' exo/endoribonuclease RNase J. Dorleans A, Li de la Sierra-Gallay I, Piton J, Zig L, Gilet L, Putzer H, Condon C; Structure. 2011;19:1252-1261. PMID:21893286

2: Structural insights into the dual activity of RNase J. Li de la Sierra-Gallay I, Zig L, Jamalli A, Putzer H; Nat Struct Mol Biol. 2008;15:206-212. PMID:18204464