Supplementary Figure 2: 3D classification scheme for cryo-EM ribosome–NatA complex.
From: Ribosome–NatA architecture reveals that rRNA expansion segments coordinate N-terminal acetylation
Particles were picked automatically with Gautomatch, and 2D classification was used to discard non-ribosomal particles. Remaining particles were subjected to 3D refinement and classification. The highest populated classes with ES27a in the exit position were joined and classified according to their tRNA states. Particles containing tRNAs in the A- and P-site were merged and used for further classification with a mask on the ribosomal tunnel exit region. One of the three classes showed well-defined additional density at the exit region for NatA and was refined to an overall resolution of 3.4 Å.
