1w9c

File:1w9c.jpg

spinqualitylabelsall models 1w9c, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D

PROTEOLYTIC FRAGMENT OF CRM1 SPANNING SIX C-TERMINAL HEAT REPEATS

Overview

CRM1/Exportin1 mediates the nuclear export of proteins bearing a, leucine-rich nuclear export signal (NES) by forming a cooperative ternary, complex with the NES-bearing substrate and the small GTPase Ran. We, present a structural model of human CRM1 based on a combination of X-ray, crystallography, homology modeling, and electron microscopy. The, architecture of CRM1 resembles that of the import receptor transportin1, with 19 HEAT repeats and a large loop implicated in Ran binding. Residues, critical for NES recognition are identified adjacent to the cysteine, residue targeted by leptomycin B (LMB), a specific CRM1 inhibitor. We, present evidence that a conformational change of the Ran binding loop, accounts for the cooperativity of Ran- and substrate binding and for the, selective enhancement of CRM1-mediated export by the cofactor RanBP3. Our, findings indicate that a single architectural and mechanistic framework, can explain the divergent effects of RanGTP on substrate binding by many, import and export receptors.

About this Structure

1W9C is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Architecture of CRM1/Exportin1 suggests how cooperativity is achieved during formation of a nuclear export complex., Petosa C, Schoehn G, Askjaer P, Bauer U, Moulin M, Steuerwald U, Soler-Lopez M, Baudin F, Mattaj IW, Muller CW, Mol Cell. 2004 Dec 3;16(5):761-75. PMID:15574331

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