This entry represents a group of SNF2 domain-containing proteins from plants, including CLSY1-3 and DRD1 from Arabidopsis. CLSY and DRD1 contain a SNF2-like domain and a helicase domain near the C terminus. They are required for siRNA-directed DNA methylation in Arabidopsis [, ]. Polymerases IVa/Pol IV and Pol IVb/Pol V are plant-specific RNA polymerases involved in in multiple small RNA-mediated gene silencing pathways. CLSY1 is required for proper localization of both NRPD1 (the largest subunit of Pol IV) and RDR2 []. DRD1 has been shown to mediate RNA polymerases IV and V (Pol IV and Pol V) recruitment to chromatin [, ]. Interestingly, DRD1 and Pol V appear to be required not only for RNA-directed de novo methylation, but also for full erasure of methylation when the RNA trigger is withdrawn [].
