Fig. 2: Design and characterization of binding angles.

A Front view of the DNA origami building block. B Side view of bonded pair at binding angle θ, with magnified views of extruded overhangs. C Left: cryo-EM reconstruction of +10δ dimers. Right: binding angle distributions for +6δ (blue) and +10δ (red) dimers. Dashed lines are measurements assumed to be equilibrated at 136 K, the solid line is rescaled to 298 K. Two extreme conformations are shown. D Top row: (left) oxDNA-generated mean configuration of +10δ dimers at 298 K, (right) binding angle distributions for +6δ (blue) and +10δ (red). Dashed lines are for 136 K, solid lines are for 298 K. For clarity, histograms are displayed only for 136 K. Two extreme conformations at 136 K are shown. Bottom row: oxDNA mean configuration of +15δ dimers with zoomed-in views of overhangs and two-thymine spacers. E Anisotropic monomers with directional labeling: top (dotted) and bottom (solid) orientations. F Monomers with side 1 binding to side 2 assemble into vertices. G TEM images of vertices. H Selectivity of vertices of different sizes as angle-domain length varies, obtained from gel electrophoresis. Each color signifies a unique vertex. I Monomers with sides 1 and 2 both binding to themselves assemble into strips or rings. J TEM images of rings. K Selectivity of rings of different sizes as angle-domain length varies, derived from gel electrophoresis. L Summary of binding angles from geometrical prediction (•, black), oxDNA dimer simulation (×), cryo-EM multibody analysis (•, blue), and vertex (□) and ring (♢) gel electrophoresis assembly analysis (red for positive and green for negative angles). Solid line indicates the linear fit to the vertex and ring assembly results. Error bars indicate standard deviations. All values are either obtained or scaled to 298 K.