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From Proteopedia
COWPEA MOSAIC VIRUS (CPMV)
Structural highlights
FunctionPOL2_CPMVS Movement protein: transports viral genome to neighboring plant cells directly through plasmosdesmata, without any budding. The movement protein allows efficient cell to cell propagation, by bypassing the host cell wall barrier. Acts by forming a tubular structure at the host plasmodesmata, enlarging it enough to allow free passage of virion capsids. Binds to GTP and to single-stranded RNA and single-stranded DNA in a non-sequence-specific manner.[1] [2] [3] [4] The cleavable C-terminus of small coat protein seems to be involved in the packaging of the virion RNAs. Also seems to act as suppressor of post-transcriptional gene silencing (PTGS), a mechanism of plant viral defense that limits the accumulation of viral RNAs.[5] [6] [7] [8] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedComoviruses 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. The refined crystal structure of cowpea mosaic virus at 2.8 A resolution.,Lin T, Chen Z, Usha R, Stauffacher CV, Dai JB, Schmidt T, Johnson JE Virology. 1999 Dec 5;265(1):20-34. PMID:10603314[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Cowpea mosaic virus | Large Structures | Chen Z | Dai J-B | Johnson JE | Lin T | Schmidt T | Stauffacher CV | Usha R
