1nyi
From Proteopedia
(New page: 200px<br /><applet load="1nyi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nyi, resolution 2.85Å" /> '''Crosslinked Hammerhe...) |
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| - | [[Image:1nyi.gif|left|200px]]<br /><applet load="1nyi" size=" | + | [[Image:1nyi.gif|left|200px]]<br /><applet load="1nyi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nyi, resolution 2.85Å" /> | caption="1nyi, resolution 2.85Å" /> | ||
'''Crosslinked Hammerhead Ribozyme Initial State'''<br /> | '''Crosslinked Hammerhead Ribozyme Initial State'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We have captured the structure of a pre-catalytic conformational | + | We have captured the structure of a pre-catalytic conformational intermediate of the hammerhead ribozyme using a phosphodiester tether formed between I and Stem II. This phosphodiester tether appears to mimic interactions in the wild-type hammerhead RNA that enable switching between nuclease and ligase activities, both of which are required in the replicative cycles of the satellite RNA viruses from which the hammerhead ribozyme is derived. The structure of this conformational intermediate reveals how the attacking nucleophile is positioned prior to cleavage, and demonstrates how restricting the ability of Stem I to rotate about its helical axis, via interactions with Stem II, can inhibit cleavage. Analogous covalent crosslinking experiments have demonstrated that imposing such restrictions on interhelical movement can change the hammerhead ribozyme from a nuclease to a ligase. Taken together, these results permit us to suggest that switching between ligase and nuclease activity is determined by the helical orientation of Stem I relative to Stem II. |
==About this Structure== | ==About this Structure== | ||
| - | 1NYI is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with CO and G as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1NYI is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=CO:'>CO</scene> and <scene name='pdbligand=G:'>G</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NYI OCA]. |
==Reference== | ==Reference== | ||
A helical twist-induced conformational switch activates cleavage in the hammerhead ribozyme., Dunham CM, Murray JB, Scott WG, J Mol Biol. 2003 Sep 12;332(2):327-36. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12948485 12948485] | A helical twist-induced conformational switch activates cleavage in the hammerhead ribozyme., Dunham CM, Murray JB, Scott WG, J Mol Biol. 2003 Sep 12;332(2):327-36. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12948485 12948485] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Dunham, C | + | [[Category: Dunham, C M.]] |
| - | [[Category: Murray, J | + | [[Category: Murray, J B.]] |
| - | [[Category: Scott, W | + | [[Category: Scott, W G.]] |
[[Category: CO]] | [[Category: CO]] | ||
[[Category: G]] | [[Category: G]] | ||
[[Category: hammerhead ribozyme crosslink conformational change]] | [[Category: hammerhead ribozyme crosslink conformational change]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:11:28 2008'' |
Revision as of 12:11, 21 February 2008
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Crosslinked Hammerhead Ribozyme Initial State
Overview
We have captured the structure of a pre-catalytic conformational intermediate of the hammerhead ribozyme using a phosphodiester tether formed between I and Stem II. This phosphodiester tether appears to mimic interactions in the wild-type hammerhead RNA that enable switching between nuclease and ligase activities, both of which are required in the replicative cycles of the satellite RNA viruses from which the hammerhead ribozyme is derived. The structure of this conformational intermediate reveals how the attacking nucleophile is positioned prior to cleavage, and demonstrates how restricting the ability of Stem I to rotate about its helical axis, via interactions with Stem II, can inhibit cleavage. Analogous covalent crosslinking experiments have demonstrated that imposing such restrictions on interhelical movement can change the hammerhead ribozyme from a nuclease to a ligase. Taken together, these results permit us to suggest that switching between ligase and nuclease activity is determined by the helical orientation of Stem I relative to Stem II.
About this Structure
1NYI is a Protein complex structure of sequences from [1] with and as ligands. Full crystallographic information is available from OCA.
Reference
A helical twist-induced conformational switch activates cleavage in the hammerhead ribozyme., Dunham CM, Murray JB, Scott WG, J Mol Biol. 2003 Sep 12;332(2):327-36. PMID:12948485
Page seeded by OCA on Thu Feb 21 14:11:28 2008
