Figure 5.

Model of flap removal and the creation of a ligatable nick by MGME1 and POLγ. MGME1 is shown together with a flap substrate at the top. The outcome of cleavage is a pool of three types of products containing 1 nt gaps, nicks or short flaps (second row). POLγ can edit the imprecisely cleaved products to create ligatable nicks (bottom rows). Gaps can be filled in (left). Short flaps can be removed by two alternative pathways: through 3′-5′excision of the 3′-end strand a complementary flap can reanneal to the temple (middle), or, through strand displacement synthesis the flap can be extended to a long flap to enable a second round of MGME1 cleavage (right).