Fig. 4. Order of binding of hDNMTs. The GST–DNMT fusion peptides of hDNMT3a and hDNMT3b used for enzyme complex formation are indicated above each blot, with amino acid residue numbers shown in parentheses. Positive and negative controls are purified hDNMT1, hDNMT3a, hDNMT3b and GST protein, respectively. Molecular weight markers are in kDa. Antibodies used for the blots are indicated below each panel. (A) Immunoblot of bound hDNMT1 to various GST fusion fragments of hDNMT3a on GST beads. (B) A similar immunoblot showing various GST fusion peptides of hDNMT3b on GST beads bound to hDNMT1. (C) Identification of the full-length hDNMT3b binding to the hDNMT1–DNMT3a complex. (D) Identification of the full-length hDNMT3a binding to the hDNMT1–DNMT3b complex.