Indeed right! 🤩 This poor tRNA is very distorted by NSUN2!

Thank you very much Flo! 😁

We trapped a post-catalytic state of NSUN2 using a C271S mutation strategy, stabilising the enzyme RNA complex.

Mass photometry confirms formation of a stable complex, and our map reveals density consistent with a covalent NSUN2-tRNA intermediate.

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Our structure shows that NSUN2 binding induces a major distortion of the tRNA fold, enabling the target cytidine from the variable loop to flip into the active site for methylation.
(see video 👇)

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NSUN2 reads RNA shape, not sequence, binding broadly but acting on well-folded substrates such as mature CCA-containing tRNAs or vault RNA 1.1.

RNA specificity experiments were carried out by the amazing @ariannadf.bsky.social

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We also investigated the G679R mutation in the RNA-binding domain of NSUN2 (PUA), which is linked to Dubowitz syndrome, a rare neurodevelopmental condition.

MD simulations performed by Kanhaya Lal show impaired RNA binding and accommodation of the acceptor stem and CCA end.

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We used an integrative structural biology approach using #XL-MS, with @admassspec.bsky.social and Andrea Graziadei from @humantechnopole.bsky.social

These datasets provide complementary evidence that reinforces and extends our structural model.

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Finally, we used a mild photocrosslinking strategy (pXL-EM) to improve reconstruction quality, inspired by its successful use in recent work from @alessandrovannini.bsky.social at Human Technopole, led by @aleborsellini.bsky.social.

Have a look at his preprint doi.org/10.64898/202...

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We thank @humantechnopole.bsky.social and @embo.org for funding support, collaborators from @ox.ac.uk, and all the authors involved in this work.

We would love your feedback!

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🚨 Preprint alert!

We solved the structure of human NSUN2 bound to Asp tRNA, revealing how it installs m⁵C and recognizes RNAs
#CryoEM #RNABiology

A collab between Casañal & Gullerova labs, with @miclass.bsky.social and me working side by side as co-first authors

🔗 doi.org/10.64898/202...
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