Figure 2.

Formation of ssDNAs after delivery of a double chain break at λ’s XhoI site. A schematic representation of events following the delivery of a double chain break at λ’s XhoI (X) site (intermediate I). After cleavage, the 5′ DNA end is resected using λ’s Redα/β complex (intermediate II) exposing 3′ single-strand overhangs. Once the α/β complex passes the proximal EcoRI (E) site, this site becomes unavailable for restriction in vitro, leading to the formation of intermediate III. The sizes of the anticipated DNA fragments after in vitro digestion with EcoRI are presented below the figure.