1mvb
STRUCTURE OF A PROTEIN CAPSID OF THE T59S MUTANT OF PHAGE MS2
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OverviewOverview
In MS2 assembly of phage particles results from an interaction between a, coat protein dimer and a stem-loop of the RNA genome (the operator, hairpin). Amino acid residues Thr45, which is universally conserved among, the small RNA phages, and Thr59 are part of the specific RNA binding, pocket and interact directly with the RNA; the former through a hydrogen, bond, the latter through hydrophobic contacts. The crystal structures of, MS2 protein capsids formed by mutants Thr45Ala and Thr59Ser, both with and, without the 19 nt wild-type operator hairpin bound, are reported here. The, RNA hairpin binds to these mutants in a similar way to its binding to, wild-type protein. In a companion paper both mutants are shown to be, deficient in RNA binding in an in vivo assay, but in vitro the equilibrium, dissociation constant is significantly higher than wild-type for the, Thr45Ala mutant. The change in binding affinity of the Thr45Ala mutant is, probably a direct consequence of removal of direct hydrogen bonds between, the protein and the RNA. The properties of the Thr59Ser mutant are more, difficult to explain, but are consistent with a loss of non-polar contact.
About this StructureAbout this Structure
1MVB is a Single protein structure of sequence from Enterobacterio phage ms2. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of MS2 coat protein mutants in complex with wild-type RNA operator fragments., van den Worm SH, Stonehouse NJ, Valegard K, Murray JB, Walton C, Fridborg K, Stockley PG, Liljas L, Nucleic Acids Res. 1998 Mar 1;26(5):1345-51. PMID:9469847
Page seeded by OCA on Tue Nov 20 21:43:41 2007