Fig. 6: Interactions between the CATC and underlying triplexes.

a Ribbon models of a CATC and triplexes Ta and Tc. b, c Density (transparent gray) and model (ribbon) of the blue boxed region in a, demonstrating the interactions between the anchor domain and N-terminal helix of BGLF1 and Ta. d Zoomed-in view of the magenta boxed region in a, illustrating that a loop in Tri2A of Ta inserts into a shallow groove of BGLF1 (surface representation). e–h Ribbon models and densities of the black boxed region in a, illustrating the CATC-Tc interactions. The dashed line in f illustrates the tracing of the unmodeled N-terminal region of the BVRF1 protein. g Density map of the same region as in f, showing the discontinues densities putatively contributed by the unmodeled N-terminal region of the BVRF1. h Superimposition between the sharpened map (colored as in g) and the unsharpened map (transparent gray), showing the discontinued densities in the sharpened map became continued densities in the unsharpened map and are connected to the N-terminal extension of the upper BVRF1.