Fig. 1.

Confirmation of methyltransferase functionality in E. coli. a pNJ020 plasmid map with NlaIII restriction sites, including NlaIII* that overlaps with the GTCAT methylation site. When blocked by methylation, NlaIII* is not cut by NlaIII, resulting in a 455 bp band rather than 393 and 62 bp bands. b Agarose gel of restriction digests of plasmid pNJ020 isolated from E. coli Top10 (lanes 1, 3, and 5) and from methylating strain AG2006 (lanes 2, 4, and 6). Methylation at GTCAT is indicated by a band shift from 393 to 455 bp (lane 1 vs 2) or complete blockage of digestion by GGCC (lane 3 vs 4) and GCWGC (lane 5 vs 6)