1RRP: Structure of the Ran-gppnhp-ranbd1 Complex

Citation:
Abstract
The protein Ran is a small GTP-binding protein that binds to two types of effector inside the cell: Ran-binding proteins, which have a role in terminating export processes from the nucleus to the cytoplasm, and importin-beta-like molecules that bind cargo proteins during nuclear transport. The Ran-binding domain is a conserved sequence motif found in several proteins that participate in these transport processes. The Ran-binding protein RanBP2 contains four of these domains and constitutes a large part of the cytoplasmic fibrils that extend from the nuclear-pore complex. The structure of Ran bound to a non-hydrolysable GTP analogue (Ran x GppNHp) in complex with the first Ran-binding domain (RanBD1) of human RanBP2 reveals not only that RanBD1 has a pleckstrin-homology domain fold, but also that the switch-I region of Ran x GppNHp resembles the canonical Ras GppNHp structure and that the carboxy terminus of Ran is wrapped around RanBD1, contacting a basic patch on RanBD1 through its acidic end. This molecular 'embrace' enables RanBDs to sequester the Ran carboxy terminus, triggering the dissociation of Ran x GTP from importin-beta-related transport factors and facilitating GTP hydrolysis by the GTPase-activating protein ranGAP. Such a mechanism represents a new type of switch mechanism and regulatory protein-protein interaction for a Ras-related protein.
PDB ID: 1RRPDownload
MMDB ID: 51213
PDB Deposition Date: 1999/1/15
Updated in MMDB: 2012/11 
Experimental Method:
x-ray diffraction
Resolution: 2.96  Å
Source Organism:
Similar Structures:
Biological Unit for 1RRP: dimeric; determined by author and by software (PISA)
Molecular Components in 1RRP
Label Count Molecule
Proteins (2 molecules)
1
RAN
Molecule annotation
1
Nuclear Pore Complex Protein Nup358
Molecule annotation
Chemicals (2 molecules)
1
1
2
1
* Click molecule labels to explore molecular sequence information.

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