Figure 1.
Real-space variance of Thermus thermophilus 70S ribosome in which the ternary complex of elongation factor Tu (EF-Tu), tRNA and guanine nucleotide has been trapped on the ribosome using the antibiotic kirromycin [44]. The structure was originally determined to 6.4 Å from a data set of 323,688 2D projection images that were pre-selected by multi-reference refinement from a total of 586,329 projection images. The 3D variance map was calculated from 170,000 bootstrap volumes. The regions of high variance include location of E-site tRNA and L1 protuberance (left) and also part of the stalk base (right) showing there is still localized heterogeneity in these regions in agreement with our previous analysis [44].