Figure 2.

Artemis activity on other DNA substrates. We propose that Artemis maintains the three contact points on other substrates (ssDNA, pseudo-Y, 5′ flaps and symmetrical bubble structures) by remodeling the end into ‘hairpin-like’ structures. While less apparent, ssDNA has the ability to fold back and base pair with itself to create the ‘hairpin-like’ structures. Contact point A (blue dot) is located on the 5′→3′ (top) strand at the ss/dsDNA boundary. Contact point B (green dot) is located on the 3′→5′ (bottom) strand directly across from Contact point A. Contact point C (catalytic site, red arrowhead) is located 1-nt on the 5′ side of Contact point B as shown in the figure.