Figure 3. Human aa-tRNA accommodation occurs through a 3’-CCA end dependent pathway.

(A) Approximate free energy $(\Delta {\mathsf{G}}^{\ast })$ landscape of tRNA accommodation as measured by comparison of the ${\mathsf{R}}_{\mathsf{elbow}}$ and ${\mathsf{R}}_{\mathsf{CCA}}$ distance measurements from simulations using potential 1. (B) Representative structure of EA-1. Complete 80S structure of EA-1 (i). Representation of the accommodation corridor of the ribosome with aa-tRNA engaging H89 in EA-1 (ii). Zoom in of accommodation corridor with aa-tRNA engaging H89 in EA-1 (iii). Representation of the accommodation corridor in EA-1 from the LSU perspective (iv). Zoom in of the 3’ CCA end of the aa-tRNA interacting with H71 in EA-1 (v). (C) Representative structure of the accommodation corridor during transition path from EA-1 to EA-2 (Path). Complete 80S structure of Path (i). Representation of the accommodation corridor of the ribosome with aa-tRNA engaging H71 in Path (ii). Zoom in of the Path position with the aa-tRNA interacting with H89 (iii). Representation of the accommodation corridor in Path from the LSU perspective (iv). Zoom in of the 3’ CCA end of the aa-tRNA interacting with H71 in Path (v). (D) Representative structure of EA-2. Complete 80S structure of EA-2 (1). Representation of the accommodation corridor of the ribosome wiith aa-tRNA engaging H71 after passing H89 (ii). Zoom in of the EA-2 position with the aa-tRNA interacting with H89 (iii).Representation of the accommodation corridor in EA-2 from the LSU perspective (iv). Zoom in of the 3’ CCA end of the aa-tRNA interacting with H71 in EA-2(v). In these models ${\mathsf{R}}_{\mathsf{elbow}}$ highlighted in blue and ${\mathsf{R}}_{\mathsf{CCA}}$ highlighted in red, while the rRNA (white and grey), ribosomal proteins (blue), peptidyl-tRNA (orange), aa-tRNA (yellow), H89 (grey), H90 (mauve), H71 (green), h18 (purple), H44 (red), and mRNA (green) are represented.