FIG. 3.

Sequence-specific DNA methylation by purified M.PabI. (A) The purified M.PabI protein was analyzed using SDS-PAGE with 12% (wt/vol) acrylamide together with low-range-molecular-weight standards (Bio-Rad Laboratories), followed by staining with Coomassie brilliant blue. The molecular mass of M.PabI (arrow) was estimated to be about 52 kDa. (B) In vitro methylation of the oligoduplex substrates (oligoduplex 1, +; oligoduplex 2, −; see Table 1) by the purified M.PabI protein with [methyl-¹⁴C]AdoMet as the methyl donor. Separation of the products was performed as described in Materials and Methods.