(A) (Top) Architecture of state pre-A1. (Bottom) Zoomed view highlighting the NGDN (cyan, transparent surface) binding site near UTP20 (yellow), U3IP2 (purple), and ribosomal proteins eS4, eS24, and uS4. (B) (Top) Architecture of state pre-A1*. (Bottom) Zoomed view highlighting the loss of NGDN (cyan) and rearrangement of the U3IP2 N terminus. (C) (Top) Architecture of state post-A1. (Bottom) Zoomed view highlighting the presence of the EXOSC10 (pink, transparent surface) lasso with four peptide epitopes (I to IV) near the moved eS4.