Fig. 3. Structural heterogeneity of in situ SSU processome particles.

A–C Three distinct SSU processome class averages (Class 1–3) with different similarity to published structures are detected. D There is a clear trend from Class 1 to Class 3 toward a more compact arrangement of the 5′ and central domains. This is particularly evident when all three STA structures are aligned and superimposed, and indicates a sequence of maturation (Supplementary Movie 2). E The relative abundance of each class is subject to external stimuli. While Class 2 dominates during logarithmic (log) and stationary growth (stat), Class 1 becomes the predominant form when treated with diazaborine (DAZ), a drg1 AAA-ATPase inhibitor, and when ribogenesis is stimulated (dark). PDB model for A–C: 5WYJ. See Supplementary Fig. 6 for a structural comparison with other maps. Source data are provided as a Source Data file.