TY - JOUR T1 - Cryo-EM of a viral RNA and RNA-protein complex reveals how structural dynamics and novel tRNA mimicry combine to hijack host machinery JF - bioRxiv DO - 10.1101/2020.09.18.302638 SP - 2020.09.18.302638 AU - Steve L. Bonilla AU - Madeline E. Sherlock AU - Andrea MacFadden AU - Jeffrey S. Kieft Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/08/29/2020.09.18.302638.abstract N2 - Viruses require multifunctional structured RNAs to hijack their host’s biochemistry, but their mechanisms can be obscured by the difficulty of solving conformationally dynamic RNA structures. Using cryo-EM, we visualized the structure of the mysterious viral tRNA-like structure (TLS) from brome mosaic virus (BMV), which affects replication, translation, and genome encapsidation. Structures in isolation and bound to tyrosyl-tRNA synthetase (TyrRS) show that this ∼55 kDa purported tRNA mimic undergoes large conformational rearrangements to bind TyrRS in a form that differs dramatically from tRNA. Our studies reveal how viral RNAs can use a combination of static and dynamic RNA structures to bind host machinery through highly noncanonical interactions and highlights the utility of cryo-EM for visualizing small conformationally dynamic structured RNAs.Competing Interest StatementThe authors have declared no competing interest. ER -