Fig. 2. In-cell cryo-ET reveals the presence of an RNAP-ribosome supercomplex.
(A) Left: tomographic slice of a M. pneumoniae cell. Right: classification of 108,501 ribosome sub-tomograms from M. pneumoniae cells. (B) Left: 5.6 Å in-cell 70S ribosome density. Insert: density near the peptide exit tunnel (dashed circle) shows two helices not accounted for by the fitted homology model (L22 and L29). (C) 9.2 Å in-cell structure of RNAP-ribosome supercomplexes (2.8% in (A)), fitted with homology models. Arrowheads indicate remaining unassigned density.