CRM1 (also known as Exportin1) mediates the nuclear export of proteins bearing a leucine-rich nuclear export signal (NES). CRM1 forms a complex with the NES containing protein and the small GTPase Ran. This region forms an alpha helical structure formed by six helical hairpin motifs that are structurally similar to the HEAT repeat, but share little sequence similarity to the HEAT repeat (PUBMED:15574331).
CRM1 (also known as exportin1) mediates the nuclear export of proteins bearing a leucine-rich nuclear export signal (NES). CRM1 forms a complex with the NES containing protein and the small GTPase Ran.
This entry represents the C-terminal domain of CRM1. It forms an alpha helical structure formed by six helical hairpin motifs that are structurally similar to the HEAT repeat, but share little sequence similarity to the HEAT repeat [ (PUBMED:15574331) ].
GO function:
nuclear export signal receptor activity (GO:0005049)
Family alignment:
There are 1759 CRM1_C domains in 1757 proteins in SMART's nrdb database.
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Evolution (species in which this domain is found)
Taxonomic distribution of proteins containing CRM1_C domain.
This tree includes only several representative species. The complete taxonomic breakdown of all proteins with CRM1_C domain is also avaliable.
Click on the protein counts, or double click on taxonomic names to display all proteins containing CRM1_C domain in the selected taxonomic class.
Architecture of CRM1/Exportin1 suggests how cooperativity is achievedduring formation of a nuclear export complex.
Mol Cell. 2004; 16: 761-75
Display abstract
CRM1/Exportin1 mediates the nuclear export of proteins bearing aleucine-rich nuclear export signal (NES) by forming a cooperative ternarycomplex with the NES-bearing substrate and the small GTPase Ran. Wepresent a structural model of human CRM1 based on a combination of X-raycrystallography, homology modeling, and electron microscopy. Thearchitecture of CRM1 resembles that of the import receptor transportin1,with 19 HEAT repeats and a large loop implicated in Ran binding. Residuescritical for NES recognition are identified adjacent to the cysteineresidue targeted by leptomycin B (LMB), a specific CRM1 inhibitor. Wepresent evidence that a conformational change of the Ran binding loopaccounts for the cooperativity of Ran- and substrate binding and for theselective enhancement of CRM1-mediated export by the cofactor RanBP3. Ourfindings indicate that a single architectural and mechanistic frameworkcan explain the divergent effects of RanGTP on substrate binding by manyimport and export receptors.