Complementation between inactive M.SssI fragments fused to zinc finger domains. DH10B cells contained pB6ZB-Sss[1–304], pB6ZB-Sss[1–239], pOB-Sss[241–386] or pOB-Sss[261–386] in combinations indicated by the names of the encoded fusion proteins above the lanes. Plasmids were purified from cultures grown in the absence or presence of 0.05 % arabinose. Lanes 1, undigested plasmid; lanes 2, uninduced and Hin6I-digested; lanes 3, induced and Hin6I-digested. M, DNA marker.