The Refined Crystal Structure of Cowpea Mosaic Virus at 2.8A Resolution
Lin, T., Chen, Z., Usha, R., Stauffacher, C.V., Dai, J.-B., Schmidt, T., Johnson, J.E.(1999) Virology 265: 20-34
- PubMed: 10603314
- DOI: https://doi.org/10.1006/viro.1999.0038
- Primary Citation of Related Structures:
1NY7 - PubMed Abstract:
Comoviruses are a group of plant viruses in the picornavirus superfamily. The type member of comoviruses, cowpea mosaic virus (CPMV), was crystallized in the cubic space group I23, a = 317 A and the hexagonal space group P6(1)22, a = 451 A, c = 1038 A. Structures of three closely similar nucleoprotein particles were determined in the cubic form. The roughly 300-A capsid was similar to the picornavirus capsid displaying a pseudo T = 3 (P = 3) surface lattice. The three beta-sandwich domains adopt two orientations, one with the long axis radial and the other two with the long axes tangential in reference to the capsid sphere. T = 3 viruses display one or the other of these two orientations. The CPMV capsid was permeable to cesium ions, leading to a disturbance of the beta-annulus inside a channel-like structure, suggesting an ion channel. The hexagonal crystal form diffracted X rays to 3 A resolution, despite the large unit cell. The large ( approximately 200 A) solvent channels in the lattice allow exchange of CPMV cognate Fab fragments. As an initial step in the structure determination of the CPMV/Fab complex, the P6(1)22 crystal structure was solved by molecular replacement with the CPMV model determined in the cubic cell.
Organizational Affiliation:
Department of Molecular Biology, MB-31, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA.