Molecular basis for disassembly of an importin: ribosomal protein complex by the escortin Tsr2
Damberger, Fred F.
Allain, Frédéric H.-T.
Panse, Vikram Govind
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Disordered extensions at the termini and short internal insertions distinguish eukaryotic ribosomal proteins (r-proteins) from their anucleated archaeal counterparts. Here, we report an NMR structure of such a eukaryotic-specific segment (ESS) in the r-protein eS26 in complex with the escortin Tsr2. The structure reveals how ESS attracts Tsr2 specifically to importin:eS26 complexes entering the nucleus in order to trigger non-canonical RanGTP-independent disassembly. Tsr2 then sequesters the released eS26 and prevents rebinding to the importin, providing an alternative allosteric mechanism to terminate the process of nuclear import. Notably, a Diamond–Blackfan anemia-associated Tsr2 mutant protein is impaired in binding to ESS, unveiling a critical role for this interaction in human hematopoiesis. We propose that eS26-ESS and Tsr2 are components of a nuclear sorting system that co-evolved with the emergence of the nucleocytoplasmic barrier and transport carriers Show more
Journal / seriesNature Communications
Pages / Article No.
PublisherNature Publishing Group
260676 - Dissecting the biogenesis of eukaryotic ribosomal subunits (EC)
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