1iam
From Proteopedia
STRUCTURE OF THE TWO AMINO-TERMINAL DOMAINS OF HUMAN INTERCELLULAR ADHESION MOLECULE-1, ICAM-1
Overview
The normal function of human intercellular adhesion molecule-1 (ICAM-1) is to provide adhesion between endothelial cells and leukocytes after injury or stress. ICAM-1 binds to leukocyte function-associated antigen (LFA-1) or macrophage-1 antigen (Mac-1). However, ICAM-1 is also used as a receptor by the major group of human rhinoviruses and is a catalyst for the subsequent viral uncoating during cell entry. The three-dimensional atomic structure of the two amino-terminal domains (D1 and D2) of ICAM-1 has been determined to 2.2-A resolution and fitted into a cryoelectron microscopy reconstruction of a rhinovirus-ICAM-1 complex. Rhinovirus attachment is confined to the BC, CD, DE, and FG loops of the amino-terminal Ig-like domain (D1) at the end distal to the cellular membrane. The loops are considerably different in structure to those of human ICAM-2 or murine ICAM-1, which do not bind rhinoviruses. There are extensive charge interactions between ICAM-1 and human rhinoviruses, which are mostly conserved in both major and minor receptor groups of rhinoviruses. The interaction of ICAMs with LFA-1 is known to be mediated by a divalent cation bound to the insertion (I)-domain on the alpha chain of LFA-1 and the carboxyl group of a conserved glutamic acid residue on ICAMs. Domain D1 has been docked with the known structure of the I-domain. The resultant model is consistent with mutational data and provides a structural framework for the adhesion between these molecules.
About this Structure
1IAM is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The structure of the two amino-terminal domains of human ICAM-1 suggests how it functions as a rhinovirus receptor and as an LFA-1 integrin ligand., Bella J, Kolatkar PR, Marlor CW, Greve JM, Rossmann MG, Proc Natl Acad Sci U S A. 1998 Apr 14;95(8):4140-5. PMID:9539703 Page seeded by OCA on Fri May 2 19:46:35 2008
