Distribution of disordered proteins on the bacterial (A,C) and chloroplast (B,D) ribosome (mapped over PDB entries 1JOO, 1VQ8, 3BBN and 3BBO, respectively). Panels A and B correspond to the 30S subunit, C and D to the 50S. Disordered proteins in bacterial ribosomal subunits are highlighted in pale yellow, pale blue, light blue, dark blue, orange, green, magenta and pink. Their chloroplast orthologues in Arabidopsis thaliana are marked in the same colour. Additional proteins found to be intrinsically disordered in chloroplast 30S and 50S subunits are highlighted in red. Numbers following S and L identify small and large subunit proteins, respectively. The disordered protein L7/L12 in the chloroplast 50S subunit is not marked because of it is absent in the structural data retrieved from the PDB. The average number of intrinsically disordered proteins (IDP) calculated for each ribosomal subunit is written below (for details see in Additional file 7: Table S6). The three-dimensional cartoons were drawn using PyMol 1.4.1 (Schrodinger LLC).