2FCW: Structure Of A Complex Between The Pair Of The Ldl Receptor Ligand-Binding Modules 3-4 And The Receptor Associated Protein (Rap)

Proteins of the low-density lipoprotein receptor (LDLR) family are remarkable in their ability to bind an extremely diverse range of protein and lipoprotein ligands, yet the basis for ligand recognition is poorly understood. Here, we report the 1.26 A X-ray structure of a complex between a two-module region of the ligand binding domain of the LDLR and the third domain of RAP, an escort protein for LDLR family members. The RAP domain forms a three-helix bundle with two docking sites, one for each LDLR module. The mode of recognition at each site is virtually identical: three conserved, calcium-coordinating acidic residues from each LDLR module encircle a lysine side chain protruding from the second helix of RAP. This metal-dependent mode of electrostatic recognition, together with avidity effects resulting from the use of multiple sites, represents a general binding strategy likely to apply in the binding of other basic ligands to LDLR family proteins.
PDB ID: 2FCWDownload
MMDB ID: 39261
PDB Deposition Date: 2005/12/12
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.26  Å
Source Organism:
Similar Structures:
Biological Unit for 2FCW: dimeric; determined by author and by software (PISA)
Molecular Components in 2FCW
Label Count Molecule
Proteins (2 molecules)
Alpha-2-macroglobulin Receptor-associated Protein(Gene symbol: LRPAP1)
Molecule annotation
Low-density Lipoprotein Receptor(Gene symbol: LDLR)
Molecule annotation
Chemicals (11 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB