1zdh
From Proteopedia
(New page: 200px<br /><applet load="1zdh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zdh, resolution 2.700Å" /> '''MS2 COAT PROTEIN/RN...) |
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| - | [[Image:1zdh.gif|left|200px]]<br /><applet load="1zdh" size=" | + | [[Image:1zdh.gif|left|200px]]<br /><applet load="1zdh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1zdh, resolution 2.700Å" /> | caption="1zdh, resolution 2.700Å" /> | ||
'''MS2 COAT PROTEIN/RNA COMPLEX'''<br /> | '''MS2 COAT PROTEIN/RNA COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystal structures of two complexes between recombinant MS2 capsids and | + | 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== | ==About this Structure== | ||
| - | 1ZDH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacterio_phage_ms2 Enterobacterio phage ms2]. Full crystallographic information is available from [http:// | + | 1ZDH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacterio_phage_ms2 Enterobacterio phage ms2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZDH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Enterobacterio phage ms2]] | [[Category: Enterobacterio phage ms2]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: K | + | [[Category: K Valegard,S Van Den Worm,L Liljas]] |
[[Category: coat protein]] | [[Category: coat protein]] | ||
[[Category: complex (coat protein/rna)]] | [[Category: complex (coat protein/rna)]] | ||
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[[Category: viral protein capsid]] | [[Category: viral protein capsid]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:14:29 2008'' |
Revision as of 14:14, 21 February 2008
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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
1ZDH 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
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