Targeted DNA Methylation Using an Artificially Bisected M.HhaI Fused to Zinc Fingers
(A) A schematic showing the sequence of the M.SssI fragments fused to zinc fingers via flexible linkers. (B) A restriction enzyme protection assay showing the split enzyme constructs possess a bias for methylation at the target site. Plasmids were isolated from strains grown under conditions that either repress or induce expression of the two fragments. Plasmid DNA was assayed for methylation as in Figure 2. The activity of these fusion heterodimers was attenuated by the indicated point mutations known to decrease enzyme activity in wild-type M.SssI.