6hyp
From Proteopedia
Rea1 Wild type ADP state (AAA+ ring part)
Structural highlights
FunctionMDN1_YEAST Nuclear chaperone required for maturation and nuclear export of pre-60S ribosome subunits. Functions at successive maturation steps to remove ribosomal factors at critical transition points, first driving the exit of early pre-60S particles from the nucleolus and then driving late pre-60S particles from the nucleus. Mediates ATP-dependent remodeling of the pre-ribosome just prior to export to allow maturation of 60S subunits into export-competent particles. Removes the ribosome biogenesis factor RSA4 from pre-60S ribosomal subunits in the nucleoplasm to drive nuclear export of the subunit. Involved in 3' processing of the 5.8S rRNA.[1] [2] [3] [4] Publication Abstract from PubMedThe biogenesis of 60S ribosomal subunits 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 visualise the Rea1 engine, a hexameric ring of AAA+ domains, and identify an alpha-helical bundle of AAA2 as a major ATPase activity regulator. The alpha-helical bundle interferes with nucleotide-induced conformational changes that create a docking site for the substrate binding MIDAS domain 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. The CryoEM structure of the Saccharomyces cerevisiae ribosome maturation factor Rea1.,Sosnowski P, Urnavicius L, Boland A, Fagiewicz R, Busselez J, Papai G, Schmidt H Elife. 2018 Nov 26;7. pii: 39163. doi: 10.7554/eLife.39163. PMID:30460895[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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