Fig. 7
From: Molecular basis of microhomology-mediated end-joining by purified full-length Polθ
Structural and functional models of wild-type Polθ and Polθ mutants. a Oversimplified model of PolθΔcen. Polθ-hel and Polθ-pol are represented by two spheres of radius 2.8 nm (the gyration radius of each domain). These spheres are linked by 6 beads of 1 nm in diameter, representing the (GGGGS)3 linker. b Typical cluster formation scheme. Polθ-hel is attracted to Polθ-hel (orange with orange), and Polθ-pol to Polθ-pol (blue with blue), while all other bead interactions are repulsive. The PolθΔcen monomers multimerize forming parallel complexes that stack upon each other, see also Supplementary Movies 5 and 6. c, d EM images of multimeric PolθΔcen (c) and Polθ + ssDNA (d) gel-like complexes at different scales alongside complexes of similar shapes obtained from simulations. The simulated molecular structures and EM images are shown using the same magnification. e Model of Polθ activity on long (≥ 70 nt) ssDNA. Polθ-hel promotes Polθ-pol MMEJ in cis in an ATPase independent manner. f Polθ-pol primarily promotes ssDNAx via snap-back replication on relatively long ssDNA due to the absence of helicase attachment. g PolθΔcen exhibits identical MMEJ activity to Polθ on long (≥ 70 nt) ssDNA. h Polθ-cen suppresses Polθ activity on short ssDNA. i Polθ-pol promotes MMEJ of short (≤ 12 nt) ssDNA. j PolθΔcen promotes MMEJ on short (≤ 12 nt) ssDNA like Polθ-pol
