2vtu
From Proteopedia
crystal structure of bacteriophage MS2 covalent coat protein dimer
Structural highlights
FunctionCAPSD_BPMS2 Self-assembles to form the T=3 icosahedral virus shell that protects the viral nucleic acid. Acts as a translational repressor by binding with high specificity to a single stem-loop structure in the genomic RNA that contains the initiation codon of the gene for the viral replicase. Involved in virus assembly through the interaction between a capsid protein dimer and the multiple packaging signals present in the RNA genome.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedA covalent dimer of the bacteriophage MS2 coat protein was created by performing genetic fusion of two copies of the gene while removing the stop codon of the first gene. The dimer was crystallized in the cubic F432 space group. The organization of the asymmetric unit together with the F432 symmetry results in an arrangement of subunits that corresponds to T = 3 octahedral particles. The octahedral particles are probably artifacts created by the particular crystal packing. When it is not crystallized in the F cubic crystal form, the coat protein dimer appears to assemble into T = 3 icosahedral particles indistinguishable from the wild-type particles. To form an octahedral particle with closed surface, the dimer subunits interact at sharper angles than in the icosahedral arrangement. The fold of the covalent dimer is almost identical to the wild-type dimer with differences located in loops and in the covalent linker region. The main differences in the subunit packing between the octahedral and icosahedral arrangements are located close to the fourfold and fivefold symmetry axes where different sets of loops mediate the contacts. The volume of the wild-type virions is 7 times bigger than that of the octahedral particles. Crystal packing of a bacteriophage MS2 coat protein mutant corresponds to octahedral particles.,Plevka P, Tars K, Liljas L Protein Sci. 2008 Oct;17(10):1731-9. Epub 2008 Jul 28. PMID:18662904[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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