Extended Data Fig. 3: Cryo-EM data processing for SfSTING with 3′,3′-cGAMP.
From: Cryo-EM structure of an active bacterial TIR–STING filament complex
a, Section of a representative electron micrograph (n = 1,148 from 1 dataset) of SfSTING oligomers formed in the presence of 3′,3′-cGAMP. b, Data processing scheme used to generate c. c, Reconstructions of SfSTING complexes bound to 3′,3′-cGAMP, coloured by local resolution, masked and unmasked. d, Model of full-length SfSTING bound to 3′,3′-cGAMP which appears to have additional TIR to TIR suprafilament contacts (linking one filament to another). Insufficient resolved density for the TIR domains in this processed dataset limits further analysis of this interaction. The final uploaded model does not contain the amino acids in the TIR domains for this reason. The STING to STING cross-filament ‘tetramer’ interface is similar to the c-di-GMP single filament model but filaments do not extend beyond an average of 4–6 units.
