1LDK: Structure Of The Cul1-Rbx1-Skp1-F Boxskp2 Scf Ubiquitin Ligase Complex

Citation:
Abstract
SCF complexes are the largest family of E3 ubiquitin-protein ligases and mediate the ubiquitination of diverse regulatory and signalling proteins. Here we present the crystal structure of the Cul1-Rbx1-Skp1-F boxSkp2 SCF complex, which shows that Cul1 is an elongated protein that consists of a long stalk and a globular domain. The globular domain binds the RING finger protein Rbx1 through an intermolecular beta-sheet, forming a two-subunit catalytic core that recruits the ubiquitin-conjugating enzyme. The long stalk, which consists of three repeats of a novel five-helix motif, binds the Skp1-F boxSkp2 protein substrate-recognition complex at its tip. Cul1 serves as a rigid scaffold that organizes the Skp1-F boxSkp2 and Rbx1 subunits, holding them over 100 A apart. The structure suggests that Cul1 may contribute to catalysis through the positioning of the substrate and the ubiquitin-conjugating enzyme, and this model is supported by Cul1 mutations designed to eliminate the rigidity of the scaffold.
PDB ID: 1LDKDownload
MMDB ID: 19630
PDB Deposition Date: 2002/4/8
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Similar Structures:
Biological Unit for 1LDK: pentameric; determined by author and by software (PISA)
Molecular Components in 1LDK
Label Count Molecule
Proteins (5 molecules)
1
Cullin Homolog(Gene symbol: CUL1)
Molecule annotation
1
Cullin Homolog(Gene symbol: CUL1)
Molecule annotation
1
Ring-box Protein 1(Gene symbol: RBX1)
Molecule annotation
1
Cyclin A/cdk2-associated Protein P19(Gene symbol: SKP1)
Molecule annotation
1
Skp2-like Protein Type Gamma(Gene symbol: SKP2)
Molecule annotation
Chemicals (3 molecules)
1
3
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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