| Structural highlights
Function
CAPSD_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 PubMed
The loop between the F and G beta strands (FG loop) of the bacteriophage MS2 coat protein subunit forms inter-subunit contacts around the 5-fold and 3-fold (quasi 6-fold) axes of the T=3 protein shell. In capsids, the loop is found in two very different conformations, one in B subunits, which form the 5-fold contact, and one in A and C subunits, which form the quasi 6-fold contact. One proline residue, Pro78, is strictly conserved in the coat protein of all related bacteriophages, and in the case of MS2 this proline residue is preceded by a cis peptide bond in the B subunit. In order to probe the role of the FG loop in capsid assembly, we have determined the crystal structures of two MS2 capsids, formed by coat proteins with mutations at two positions in the FG loop, P78N or E76D. These mutants show conformational changes in the FG loops that explain the reduced temperature stability of the capsids. The P78N mutant has a normal trans peptide bond at position 78.
Crystal structures of MS2 capsids with mutations in the subunit FG loop.,Stonehouse NJ, Valegard K, Golmohammadi R, van den Worm S, Walton C, Stockley PG, Liljas L J Mol Biol. 1996 Feb 23;256(2):330-9. PMID:8594200[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Horn WT, Tars K, Grahn E, Helgstrand C, Baron AJ, Lago H, Adams CJ, Peabody DS, Phillips SE, Stonehouse NJ, Liljas L, Stockley PG. Structural basis of RNA binding discrimination between bacteriophages Qbeta and MS2. Structure. 2006 Mar;14(3):487-95. PMID:16531233 doi:https://dx.doi.org/10.1016/j.str.2005.12.006
- ↑ Plevka P, Tars K, Liljas L. Crystal packing of a bacteriophage MS2 coat protein mutant corresponds to octahedral particles. Protein Sci. 2008 Oct;17(10):1731-9. Epub 2008 Jul 28. PMID:18662904 doi:10.1110/ps.036905.108
- ↑ Rolfsson O, Middleton S, Manfield IW, White SJ, Fan B, Vaughan R, Ranson NA, Dykeman E, Twarock R, Ford J, Kao CC, Stockley PG. Direct Evidence for Packaging Signal-Mediated Assembly of Bacteriophage MS2. J Mol Biol. 2016 Jan 29;428(2 Pt B):431-48. doi: 10.1016/j.jmb.2015.11.014. Epub , 2015 Dec 1. PMID:26608810 doi:https://dx.doi.org/10.1016/j.jmb.2015.11.014
- ↑ Golmohammadi R, Valegard K, Fridborg K, Liljas L. The refined structure of bacteriophage MS2 at 2.8 A resolution. J Mol Biol. 1993 Dec 5;234(3):620-39. PMID:8254664 doi:https://dx.doi.org/10.1006/jmbi.1993.1616
- ↑ Valegard K, Murray JB, Stonehouse NJ, van den Worm S, Stockley PG, Liljas L. The three-dimensional structures of two complexes between recombinant MS2 capsids and RNA operator fragments reveal sequence-specific protein-RNA interactions. J Mol Biol. 1997 Aug 1;270(5):724-38. PMID:9245600 doi:https://dx.doi.org/10.1006/jmbi.1997.1144
- ↑ van den Worm SH, Stonehouse NJ, Valegard K, Murray JB, Walton C, Fridborg K, Stockley PG, Liljas L. Crystal structures of MS2 coat protein mutants in complex with wild-type RNA operator fragments. Nucleic Acids Res. 1998 Mar 1;26(5):1345-51. PMID:9469847
- ↑ Stonehouse NJ, Valegard K, Golmohammadi R, van den Worm S, Walton C, Stockley PG, Liljas L. Crystal structures of MS2 capsids with mutations in the subunit FG loop. J Mol Biol. 1996 Feb 23;256(2):330-9. PMID:8594200 doi:https://dx.doi.org/10.1006/jmbi.1996.0089
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