Comparison of the Dimer and Filament Complex Assemblies
(A) The 7.2-Å resolution dimer cryo-EM map colored by subunit.
(B) The dimer and filament complexes are split into three sections and rotated 90° relative to (A) and (C). Both assemblies share similar components but with different conformational arrangements. In the filament form, the monomer Cas1-Cas2-Csn2 unit shows a further rotation of the Csn2 tetramers relative to each other compared to both the dimer and monomer forms.
(C) The 7.7-Å resolution minimal unit masked filament cryo-EM map colored by subunit with a similar view to that of the dimer complex shown in (A).
(D) The dimer model is shown colored by subunit with transparent molecular surfaces calculated at 18-Å resolution shown to highlight the middle pair of Cas1-Cas2 subcomplexes. The Cas2 dimers cap the ends of two bound DNA fragments.
(E) The minimal filament model is shown colored by subunit with transparent molecular surfaces calculated at 18-Å resolution shown to highlight the middle pair of Cas1-Cas2 subcomplexes.