FIG 7 .

Mutations in the crRNA 5′ tag eliminate CRISPR attack. (A) Schematic of the complementarity between the flanking sequences (positions −1 to −8) of crRNAs (bottom) and target DNA (top). The mutated nucleotides are shown in red. (B) Effects of progressive sequence mutations in the 5′-tag sequence on transformation efficiency. The transformation efficiency of the empty plasmid pLI50 was set at 100%. The construct pLI-S36, which contains the native repeat, was used as a positive control. The mutated nucleotides are shown in red. (C) The relative targeting activity of mecA-targeting constructs contained a series of mutations in the 5′-tag sequence. The targeting activity of empty plasmid pLI50 was set at zero. The construct pLI-S36 was taken as a positive control. Five independent transformants were analyzed for each construct with bars indicating standard deviations.