3IBV

Karyopherin cytosolic state

Summary for 3IBV

• Entry DOI: 10.2210/pdb3ibv/pdb
• Related: 3ICQ
• Descriptor: Exportin-T, CALCIUM ION (2 entities in total)
• Functional Keywords: karyopherin, exportin, heat repeat, cytoplasm, nucleus, rna-binding, transport, trna processing, trna-binding, rna binding protein
• Biological source: Schizosaccharomyces pombe (Fission yeast)
• Cellular location: Nucleus: O94258
• Total number of polymer chains: 2
• Total formula weight: 220869.86

Authors

Cook, A.G.,Fukuhara, N.,Jinek, M.,Conti, E. (deposition date: 2009-07-17, release date: 2009-08-25, Last modification date: 2024-03-20)

Primary citation

Cook, A.G.,Fukuhara, N.,Jinek, M.,Conti, E.
Structures of the tRNA export factor in the nuclear and cytosolic states
Nature, 461:60-65, 2009

PubMed Abstract: Transfer RNAs are among the most ubiquitous molecules in cells, central to decoding information from messenger RNAs on translating ribosomes. In eukaryotic cells, tRNAs are actively transported from their site of synthesis in the nucleus to their site of function in the cytosol. This is mediated by a dedicated nucleo-cytoplasmic transport factor of the karyopherin-beta family (Xpot, also known as Los1 in Saccharomyces cerevisiae). Here we report the 3.2 A resolution structure of Schizosaccharomyces pombe Xpot in complex with tRNA and RanGTP, and the 3.1 A structure of unbound Xpot, revealing both nuclear and cytosolic snapshots of this transport factor. Xpot undergoes a large conformational change on binding cargo, wrapping around the tRNA and, in particular, binding to the tRNA 5' and 3' ends. The binding mode explains how Xpot can recognize all mature tRNAs in the cell and yet distinguish them from those that have not been properly processed, thus coupling tRNA export to quality control.

PubMed: 19680239
DOI: 10.1038/nature08394

Experimental method

X-RAY DIFFRACTION (3.1 Å)