1z3h
The exportin Cse1 in its cargo-free, cytoplasmic state
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OverviewOverview
Cse1 mediates nuclear export of importin alpha, the nuclear localization, signal (NLS) import adaptor. We report the 3.1 A resolution structure of, cargo-free Cse1, representing this HEAT repeat protein in its cytosolic, state. Cse1 is compact, consisting of N- and C-terminal arches that, interact to form a ring. Comparison with the structure of cargo-bound Cse1, shows a major conformational change leading to opening of the structure, upon cargo binding. The largest structural changes occur within a hinge, region centered at HEAT repeat 8. This repeat contains a conserved, insertion that connects the RanGTP and importin alpha contact sites and, that is essential for binding. In the cargo-free state, the RanGTP binding, sites are occluded and the importin alpha sites are distorted. Mutations, that destabilize the N- to C-terminal interaction uncouple importin alpha, and Ran binding, suggesting that the closed conformation prevents, association with importin alpha.
About this StructureAbout this Structure
1Z3H is a Single protein structure of sequence from Saccharomyces cerevisiae with MG as ligand. Full crystallographic information is available from OCA.
ReferenceReference
The structure of the nuclear export receptor Cse1 in its cytosolic state reveals a closed conformation incompatible with cargo binding., Cook A, Fernandez E, Lindner D, Ebert J, Schlenstedt G, Conti E, Mol Cell. 2005 Apr 29;18(3):355-67. PMID:15866177
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