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bioRxiv · 10.1101/2020.08.11.245068

Structural and molecular basis for protein-stimulated ribosomal frameshifting in Theiler's murine encephalomyelitis virus

Hill, C. H.·Cook, G.·Napthine, S.·Kibe, A.·Brown, K.·Caliskan, N.·Firth, A. E.·Graham, S. C.·Brierley, I.
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Abstract

The 2A protein of Theilers murine encephalomyelitis virus (TMEV) acts as a switch to stimulate programmed -1 ribosomal frameshifting (PRF) during infection. Here we present the X-ray crystal structure of TMEV 2A and define how it recognises the stimulatory RNA element. We demonstrate a critical role for bases upstream of the originally predicted stem-loop, providing evidence for a pseudoknot-like conformation and suggesting that the recognition of this pseudoknot by beta-shell proteins is a conserved feature in cardioviruses. Through examination of PRF in TMEV-infected cells by ribosome profiling, we identify a series of ribosomal pauses around the site of PRF induced by the 2A-pseudoknot complex. Careful normalisation of ribosomal profiling data with a 2A knockout virus facilitated the identification, through disome analysis, of ribosome stacking at the TMEV frameshifting signal. These experiments provide unparalleled detail of the molecular mechanisms underpinning Theilovirus protein-stimulated frameshifting.

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Hill, C. H., Cook, G., Napthine, S., Kibe, A., Brown, K., Caliskan, N., Firth, A. E., Graham, S. C., Brierley, I.. 2020-08-11. Structural and molecular basis for protein-stimulated ribosomal frameshifting in Theiler's murine encephalomyelitis virus. https://doi.org/10.1101/2020.08.11.245068

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