1QGC

STRUCTURE OF THE COMPLEX OF A FAB FRAGMENT OF A NEUTRALIZING ANTIBODY WITH FOOT AND MOUTH DISEASE VIRUS

Summary for 1QGC

• Entry DOI: 10.2210/pdb1qgc/pdb
• Descriptor: PROTEIN (VIRUS CAPSID PROTEIN VP1), PROTEIN (VIRUS CAPSID PROTEIN VP2), PROTEIN (VIRUS CAPSID PROTEIN VP3), ... (6 entities in total)
• Functional Keywords: virus-antibody complex, icosahedral virus, virus-immune system complex, virus/immune system
• Biological source: Foot-and-mouth disease virus - type C; More
• Total number of polymer chains: 6
• Total formula weight: 120905.43

Authors

Fita, I. (deposition date: 1999-04-23, release date: 2000-01-26, Last modification date: 2025-03-05)

Primary citation

Hewat, E.A.,Verdaguer, N.,Fita, I.,Blakemore, W.,Brookes, S.,King, A.,Newman, J.,Domingo, E.,Mateu, M.G.,Stuart, D.I.
Structure of the complex of an Fab fragment of a neutralizing antibody with foot-and-mouth disease virus: positioning of a highly mobile antigenic loop.
EMBO J., 16:1492-1500, 1997

PubMed Abstract: Data from cryo-electron microscopy and X-ray crystallography have been combined to study the interactions of foot-and-mouth disease virus serotype C (FMDV-C) with a strongly neutralizing monoclonal antibody (mAb) SD6. The mAb SD6 binds to the long flexible GH-loop of viral protein 1 (VP1) which also binds to an integrin receptor. The structure of the virus-Fab complex was determined to 30 A resolution using cryo-electron microscopy and image analysis. The known structure of FMDV-C, and of the SD6 Fab co-crystallized with a synthetic peptide corresponding to the GH-loop of VP1, were fitted to the cryo-electron microscope density map. The SD6 Fab is seen to project almost radially from the viral surface in an orientation which is only compatible with monovalent binding of the mAb. Even taking into account the mAb hinge and elbow flexibility, it is not possible to model bivalent binding without severely distorting the Fabs. The bound GH-loop is essentially in what has previously been termed the 'up' position in the best fit Fab orientation. The SD6 Fab interacts almost exclusively with the GH-loop of VP1, making very few other contacts with the viral capsid. The position and orientation of the SD6 Fab bound to FMDV-C is in accord with previous immunogenic data.

PubMed: 9130694
DOI: 10.1093/emboj/16.7.1492

Experimental method

ELECTRON MICROSCOPY (30 Å)