Extended Data Fig. 6: Cryo-EM single-particle reconstruction.
From: Rubisco condensate formation by CcmM in β-carboxysome biogenesis
a, Representative micrograph of Rubisco–M35 complexes used for single-particle reconstruction (n = 4,723 micrographs from one EM grid). b, 2D class averages of complexes in a showing extra density of SSUL bound to Rubisco in some classes. c, Meshwork representation of unsharpened D4 symmetry-averaged electron density map of the Rubisco–M35 complex (at a contour level of 2.8σ, appropriate for Rubisco), with the D4-averaged final model in backbone trace representation superposed (top). Below, zoomed-in region. Note that there is only ~50% residual density for the two SSUL modules, except for the region in which the modules overlap in the centre (helices α1). d, The workflow for single-particle data processing. The left scheme of the flowchart identified only one SSUL domain bound between two RbcL subunits. The main scheme took the units consisting of two RbcL, two RbcS and two SSUL for focused classification and further refinement to improve the map quality. See Methods for details. e, Gold-standard FSC corrected curve (masked and B-factor sharpened) of the final 3D reconstruction. The resolution is ~2.77 Å at the FSC cutoff of 0.143.
