2ms2
From Proteopedia
THE REFINED STRUCTURE OF BACTERIOPHAGE MS2 AT 2.8 ANGSTROMS RESOLUTION
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] 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 PubMedBacteriophage MS2 is an icosahedral virus with 180 copies of a coat protein forming a shell around a single-stranded RNA molecule. The coat protein subunits form a lattice with the triangulation number T = 3. The coat protein has a fold which is different from the fold of all other viral coat proteins so far known. It consists of a five-stranded beta sheet facing the inside of the particle, and a hairpin and two helices on the outside. The crystal structure has been refined at 2.8 A resolution. The final R-factor was 0.189 for reflections with F > 2 sigma, and the root-mean-square deviation from idealized bond lengths and bond angles was 0.015 A and 2.9 degrees, respectively. The three chemically identical conformers A, B and C are largely similar. The B conformer has a unique conformation in one loop, which is involved in 5-fold interactions, while the A and C conformers, which are involved in the quasi-6-fold contacts, are similar throughout the structure. One cis-proline has been identified in the B conformer but the corresponding prolines in A and C are of the trans isomer. This residue is conserved within small RNA coliphages and it is proposed that this isomerization enables a less elongated loop (FG) around the 5-fold axis, thus creating a channel. The extensive dimer contact supports the idea of dimers as initial building blocks. An assembly pathway is proposed where five dimers converge into a pentamer and 12 pentamers are linked together with free dimers creating a complete particle. The refined structure of bacteriophage MS2 at 2.8 A resolution.,Golmohammadi R, Valegard K, Fridborg K, Liljas L J Mol Biol. 1993 Dec 5;234(3):620-39. PMID:8254664[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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