1WWL: Crystal Structure Of Cd14

Lipopolysaccharide, the endotoxin of Gram-negative bacteria, induces extensive immune responses that can lead to fatal septic shock syndrome. The core receptors recognizing lipopolysaccharide are CD14, TLR4, and MD-2. CD14 binds to lipopolysaccharide and presents it to the TLR4/MD-2 complex, which initiates intracellular signaling. In addition to lipopolysaccharide, CD14 is capable of recognizing a few other microbial and cellular products. Here, we present the first crystal structure of CD14 to 2.5 angstroms resolution. A large hydrophobic pocket was found on the NH2-terminal side of the horseshoe-like structure. Previously identified regions involved in lipopolysaccharide binding map to the rim and bottom of the pocket indicating that the pocket is the main component of the lipopolysaccharide-binding site. Mutations that interfere with lipopolysaccharide signaling but not with lipopolysaccharide binding are also clustered in a separate area near the pocket. Ligand diversity of CD14 could be explained by the generous size of the pocket, the considerable flexibility of the rim of the pocket, and the multiplicity of grooves available for ligand binding.
PDB ID: 1WWLDownload
MMDB ID: 31937
PDB Deposition Date: 2005/1/6
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 1WWL: dimeric; determined by author
Molecular Components in 1WWL
Label Count Molecule
Proteins (2 molecules)
Monocyte Differentiation Antigen Cd14(Gene symbol: Cd14)
Molecule annotation
Chemicals (10 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB