Fig. 2: Dynamic interaction of Zuo1 with the 60S subunit at the peptide exit.
From: Structural remodeling of ribosome associated Hsp40-Hsp70 chaperones during co-translational folding
a Segmented density map of Zuo1 ZHD and JD (from the RNC-RAC-Ssb1 dataset), superimposed with the atomic model. JD and ZHD are colored blue and orange, respectively. The HPD motif is highlighted in cyan spheres. The density map is from a focused refinement (Map 2.4 in Supplementary Fig. 6). b Magnified view of the 60S subunit in the RAC binding region. Zuo1 models of State B1, B2 and B3 are colored blue, gold and green, respectively. H101, eL31 and H24 are colored cyan, orangered and magenta, respectively. c, Comparison of the models of Zuo1 on the 60S subunit. The HPD motif in Zuo1 JD displays up to 12° rotation and 20-Å shift with respect to U3382 of the 25S rRNA (left). The flexibility of ZHD-α3 is the structural basis of the dynamics of RAC on the 60S subunit (right). d–f Contact points of Zuo1 with the 60S subunit. Detailed views of interactions between the N-terminus of ZHD α3 and H24 (d) in State B2, between ZHD α2/α3 and eL31 (e) in State B2, and between MD and H101 (f) in State B1. The atomic models of Zuo1 are superimposed with EM density from State B2 (d, e) or State B1 (f). Selected residues of Zuo1, eL31 and 25S rRNA are shown in stick models and labelled. The density maps are from Map 2.2 and Map 2.1 in Supplementary Fig. 6. g–i, Structural comparison of the models of Zuo1 (State B1-B3) with respect to the three ribosomal contact points, H24 (g), eL31 (h) and H101 (i).
