Extended Data Fig. 1: Single-particle cryo-EM analysis of the Crt-SPARTA heterodimer and the Crt-SPARTA–gRNA–tDNA quaternary complex.

a, Workflow of cryo-EM data processing for Crt-SPARTA heterodimer. b, Left, representative cryo-EM micrograph of Crt-SPARTA heterodimer from 7,330 movies was shown; Right, representative 2D averaged classification from the particles used for final reconstruction. c, Gold-standard Fourier shell correlation (FSC) curves of the final Crt-SPARTA heterodimer. The blue line indicates the 0.143 cut-off criterion, indicating a nominal resolution of 3.27 Å. d, Local resolution cryo-EM density map calculated using cryoSPARC, blue to red indicates high to low resolution. e, Single-particle cryo-EM image processing workflow of Crt-SPARTA–gRNA–tDNA quaternary complex. f, Left, representative micrograph of Crt-SPARTA–gRNA–tDNA quaternary complex from 7,080 movies was shown; Right, representative 2D averaged class images from the particles used for final reconstruction. g, Gold-standard Fourier shell correlation (FSC) curves. The map-to-map FSC curve was calculated between the two independently refined half-maps after masking (blue line), and the overall resolution was determined by the gold-standard FSC = 0.143 criterion. h, Local map resolution of the final structure, blue to red indicates high to low resolution.