A viral RNA hijacks host machinery using dynamic conformational changes of a tRNA-like structure

A tricky mimicry RNA viruses use dynamic, multifunctional folded elements to hijack host cellular machinery. Bonillaet al . used cryo–electron microscopy (cryo-EM) to explore an RNA element from Brome mosaic virus that tricks host cell tyrosine transfer RNA synthetase (TyrRS) into adding a tyrosine to the viral genome’s 3′ end. Visualizing this RNA both in isolation and bound to a cellular TyrRS revealed a bound structure unlike the canonical transfer RNA L-like shape and conformational rearrangements in the RNA upon binding to the TyrRS, which suggests a multistep process of enzyme recognition. This study highlights the power of cryo-EM to illustrate dynamic processes involving small structured RNAs and RNA-protein complexes. —DJ