Design and Construction of a One-Dimensional DNA Track for an Artificial Molecular Motor

Figure 4

To double the length of the (ABC) unit, the pK₁ plasmid (left, with relevant restriction sites noted) was double-digested with either BbsI and NdeI (donor, including the kanamycin resistance gene “Kan,” center top) or NdeI and BsaI (recipient, center bottom). Digestion with BbsI or BsaI produces compatible overhangs between donor and recipient. Donor and recipient fragments, obtained from gel purification of each double digest, were ligated together to form a pK₂ plasmid. The two repeats of the ABC sequence in the plasmid pK₂ are joined without forming additional restriction sites.