Figure 3.

Screening of all variants for an altered specificity. Either the adenine (RV_ME, black bars) or cytosine substrate (RV_C/A, gray bars) (0.5 µM) was incubated with 1 µl protein preparation of M.EcoRV or M.EcoRV mutants (2–40 µM) in 10 µl methylation buffer containing 0.76 µM [methyl-³H]-AdoMet for 1 h at 37°C.