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1zdi
From Proteopedia
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RNA BACTERIOPHAGE MS2 COAT PROTEIN/RNA COMPLEX
Overview
Crystal structures of two complexes between recombinant MS2 capsids and, RNA operator fragments have been determined at 2.7 A resolution. The coat, protein of the RNA bacteriophage MS2 is bifunctional; it forms the, icosahedral virus shell to protect the viral nucleic acid and it acts as a, translational repressor by binding with high specificity to a unique site, on the RNA, a single stem-loop structure, containing the initiation codon, of the gene for the viral replicase. In order to determine the structure, of these protein-RNA complexes, we have used chemically synthesized, variants of the stem-loop fragment and soaked them into crystals of, recombinant capsids. The RNA stem-loop, as bound to the protein, forms a, crescent-like structure and interacts with the surface of the beta-sheet, of a coat protein dimer. It makes protein contacts with seven phosphate, groups on the 5' side of the stem-loop, with a pyrimidine base at position, -5, which stacks onto a tyrosine, and with two exposed adenine bases, one, in the loop and one at a bulge in the stem. Replacement of the wild-type, uridine with a cytosine at position -5 increases the affinity of the RNA, to the dimer significantly. The complex with RNA stem-loop having cytosine, at this position differs from that of the wild-type complex mainly by, having one extra intramolecular RNA interaction and one extra, water-mediated hydrogen bond.
About this Structure
1ZDI is a Single protein structure of sequence from Enterobacterio phage ms2. Full crystallographic information is available from OCA.
Reference
The three-dimensional structures of two complexes between recombinant MS2 capsids and RNA operator fragments reveal sequence-specific protein-RNA interactions., Valegard K, Murray JB, Stonehouse NJ, van den Worm S, Stockley PG, Liljas L, J Mol Biol. 1997 Aug 1;270(5):724-38. PMID:9245600
Page seeded by OCA on Wed Nov 21 07:24:03 2007
