Extended Data Fig. 8: cGAS interactions with the second nucleosome in trans.

a, EM envelope of the dimeric complex containing NCP1-cGAS1-cGAS2-NCP2. b, A magnified view of an additional density accounting for N-terminal tail of histone H4. c, A 3D class showing the additional EM density found (dotted circles) near the outward facing acidic patch. The dimeric structure of NCP1-cGAS1-cGAS2-NCP2 is modelled into the major density. d, Modelling of cGAS molecules on the outer sides of the two NCP molecules in the map (c) resulting in a complex of cGAS1’-NCP1-cGAS1-cGAS2-NCP2-cGAS2’. e, A representative micrograph containing a cGAS (WT)-NCP multimeric complex (n = 20 micrographs). f, Magnified view on oligomeric assemblies extracted from (e) (left), Scale bar, 10 nm, and a modelled arrangement of cGAS-NCP in cartoon representation (right). g, Differential nuclear salt fractions probed for cGAS and H2B by immunoblot from HeLa cGAS KO cells reconstituted with doxycycline-inducible WT cGAS or cGAS K285A/R300A/K427A after 2 days of doxycycline treatment. One representative experiment of n = 3 independent experiments is shown. For gel source data, see Supplementary Fig. 1.