This domain is found in HEN1 proteins from Arabidopsis. Structural characterization reveal that small RNA substrate bind to two double-stranded RNA (dsRNA)-specific binding domains, dsRBD1 and dsRBD2. This entry relates to dsRBD2 which together with dsRBD1 forms a strong grip on the duplex region of the small RNA substrate, and these interactions help position the other duplex terminus towards the MTase domain Pfam:PF13847 [1].

1: Structural insights into mechanisms of the small RNA methyltransferase HEN1. Huang Y, Ji L, Huang Q, Vassylyev DG, Chen X, Ma JB; Nature. 2009;461:823-827. PMID:19812675