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bioRxiv · 10.1101/455634

The CryoEM Structure of the Ribosome Maturation Factor Rea1

Sosnowski, P.·Urnavicius, L.·Boland, A.·Fagiewicz, R.·Busselez, J.·Papai, G.·Schmidt, H.
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Abstract

The biogenesis of the 60S ribosomal subunit is initiated in the nucleus where rRNAs and proteins form pre-60S particles. These pre-60S particles mature by transiently interacting with various assembly factors. The ~5000 amino-acid AAA+ ATPase Rea1 (or Midasin) generates force to mechanically remove assembly factors from pre-60S particles, which promotes their export to the cytosol. Here we present three Rea1 cryoEM structures. We visualize the Rea1 engine, a hexameric ring of AAA+ domains, and identify an -helical bundle of AAA2 as a major ATPase activity regulator. The -helical bundle interferes with nucleotide induced conformational changes that create a docking site for the substrate binding MIDAS domain of Rea1 on the AAA+ ring. Furthermore, we reveal the architecture of the Rea1 linker, which is involved in force generation and extends from the AAA+ ring. The data presented here provide insights into the mechanism of one of the most complex ribosome maturation factors.

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Sosnowski, P., Urnavicius, L., Boland, A., Fagiewicz, R., Busselez, J., Papai, G., Schmidt, H.. 2018-10-29. The CryoEM Structure of the Ribosome Maturation Factor Rea1. https://doi.org/10.1101/455634

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