Title : A dimeric crystal structure for the N-terminal two
domains of
intercellular adhesion molecule-1
Abstract :
- The 3.0-A structure of a 190-residue fragment of intercellular adhesion molecule-1 ( ICAM-1 , CD54) reveals two tandem Ig-superfamily (IgSF) domains
- Each of two independent molecules dimerizes identically with a symmetry-related molecule over a hydrophobic interface on the BED sheet of domain 1, in agreement with dimerization of ICAM-1 on the cell surface
- The residues that bind to the integrin LFA-1 are well oriented for bivalent binding in the dimer , with the critical Glu-34 residues pointing away from each other on the periphery
- Residues that bind to rhinovirus are in the flexible BC and FG loops at the tip of domain 1, and these and the upper half of domain 1 are well exposed in the dimer for docking to virus
- By contrast, a residue important for binding to Plasmodium falciparum-infected erythrocytes is in the dimer interface
- The presence of A' strands in both domains 1 and 2, conserved hydrogen bonds at domain junctions, and elaborate hydrogen bond networks around the key integrin binding residues in domain 1 make these domains suited to resist tensile forces during adhesive interactions
- A subdivision of the intermediate (I) set of IgSF domains is proposed in which domain 1 of ICAM-1 and previously described I set domains belong to the I1 set and domain 2 of ICAM-1 , ICAM-2 , and vascular cell adhesion molecule-1 belong to the I2 set
Output (sent_index, trigger,
protein,
sugar,
site):
Output(Part-Of) (sent_index,
protein,
site):
- 0. intercellular adhesion molecule-1, domains
- 1. intercellular adhesion molecule-1, fragment
- 1. structure of a 190, fragment
- 7. ICAM-1, domain
- 7. ICAM-1, domains
- 7. ICAM-2, domain
- 7. cell adhesion molecule-1, domain
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):