Figure 4.
(A) Time course for product formation with N660/66-mer and N645/50-mer DNA as substrates. One mole equivalent of [3H]CH3 is incorporated into N645/50-mer, whereas 2 mol are incorporated into N660/66-mer, suggesting that CcrM processively methylates DNA. (B) Time course for product formation with N660/66-mer and 60/66-mer DNA as substrates. One mole equivalent of [3H]CH3 is incorporated into 60/66-mer, whereas 2 mol are incorporated into N660/66-mer, indicating that CcrM is capable of processively methylating DNAHM but not unmethylated DNA.