key: cord-0954905-ywbnfb2j
authors: Kolatkar, Prasanna R.; Oliveira, Marcos A.; Rossmann, Michael G.; Robbins, Arthur H.; Katti, Suresh K.; Hoover-Litty, Helana; Forte, Carla; Greve, Jeffrey M.; McClelland, Alan; Olson, Norman H.
title: Preliminary X-ray crystallographic analysis of intercellular adhesion molecule-1
date: 1992-06-20
journal: Journal of Molecular Biology
DOI: 10.1016/0022-2836(92)90110-6
sha: a2bd20df3bd5366f8a351b50e25d9eb254529016
doc_id: 954905
cord_uid: ywbnfb2j

Abstract Crystals of the two ammo-terminal domains of intercellular adhesion molecule-1, the receptor for the major group of human rhinovirus serotypes, diffract to 3.0 Å resolution. The crystals are trigonal in space group P3121 or P3221 with cell dimensions of a = b = 55.7 A ̊ , c = 166.3 A ̊ , with probably six molecules per unit cell.

The roughly 100 characterized human rhinoviruses can be divided into two groups according to the cell surface receptor they recognize (Colonno, 1986) . The receptor for the major group has been identified as the intercellular adhesion molecule-l (ICAM-lf) (Greve et al., 1989; Staunton et al., 1989) . The major group of rhinoviruses includes human rhinovirus 14 (HRV14), whose three-dimensional atomic structure has been determined (Rossmann et al., 1985) , as well as HRV16, whose structure is being determined (M. A. Oliveira, M. G. Rossmann, W. M. Lee & R. R. Rueckert, unpublished results). The minor rhinovirus group includes HRVlA, whose structure is known (Kim et al., 1989) . The surface structures of homologous HRV14 and HRVlA differ in their charge distribution, but both show a large surface canyon that is thought to be the site of receptor attachment (Rossmann et aZ., 1985; Rossmann, 1989 ). Solvent exposed residues within the canyon are more conserved (Rossmann & Palmenberg, 1988) and would be inaccessible to larger antibodies, thus conserving the receptor attachment site in the face of host immune pressure for change in the antigenic viral surface. Support for this hypothesis comes from site-specific mutagenesis al., 1988; Giranda et al., 1990) suggests that ICAM-is a member of the immunoglobulin superfamily.

The protein has five immunoglobulin-like extracellular domains, but the first amino-terminal domain (Dl) provides the major interaction for binding to the major group of rhino- A secreted form of the first two domains (185 amino acid residues) of human ICAM-1, designated tICAM-(185)) has been purified from culture supernatants of a stable CHO cell line (Greve et al., 1991) to permit structural and functional analysis. This protein contains four N-linked oligosaccharide chains and, upon native isoelectric focusing, runs as a smear at a p1 of 46 to 4%. It has been desialated by treatment with neuraminidase (Genzyme, EE. 3.2.1.18; 8 h at 37°C in 100 miv-sodium acetate (pH 6.5) at 10 mg substrate/ml and 61 enzyme unit/ml), and separated from undigested material and enzyme by dialysis against 10 mM-Tris, 25 mM-NaC1 (pH 6.0) and passage through a

, where it appears in the flow-through fraction. The desialated tICAM-1( 185), designated ntICAM-1(185), had a slightly reduoed relative molecular mass of around 43,000 and formed a major species with a p1 of 5.8 upon isoelectric focusing. Based on the amino acid sequence and the carbohydrate analysis (il& = SOOO), the total relative molecular mass is around 27,000. It was crystallized ( Fig. 1) which implies one molecule per asymmetric unit. A Pt,(XH,),(N02)2 heavy-atom derivative diffraction data set has also been collected to 5 a resolution and interpreted in terms of one major Pt site. Aqueous samples were prepared for cryomicroscopy, without the addition of stains or fixatives, by quickly plunge freezing them into liquified ethane (Dubochet et al., 1988 

Cell surface receptors for picornaviruses