2jtp
From Proteopedia
(New page: 200px<br /><applet load="2jtp" size="350" color="white" frame="true" align="right" spinBox="true" caption="2jtp" /> '''Solution Structure of the Frameshift-Inducin...) |
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==Overview== | ==Overview== | ||
| - | Simian immunodeficiency virus (SIV), like its human homologues (HIV-1, HIV-2), requires a -1 translational frameshift event to properly | + | Simian immunodeficiency virus (SIV), like its human homologues (HIV-1, HIV-2), requires a -1 translational frameshift event to properly synthesize all of the proteins required for viral replication. The frameshift mechanism is dependent upon a seven-nucleotide slippery sequence and a downstream RNA structure. In SIV, the downstream RNA structure has been proposed to be either a stem-loop or a pseudoknot. Here, we report the functional, structural and thermodynamic characterization of the SIV frameshift site RNA. Translational frameshift assays indicate that a stem-loop structure is sufficient to promote efficient frameshifting in vitro. NMR and thermodynamic studies of SIV RNA constructs of varying length further support the absence of any pseudoknot interaction and indicate the presence of a stable stem-loop structure. We determined the structure of the SIV frameshift-inducing RNA by NMR. The structure reveals a highly ordered 12 nucleotide loop containing a sheared G-A pair, cross-strand adenine stacking, two G-C base-pairs, and a novel CCC triloop turn. The loop structure and its high thermostability preclude pseudoknot formation. Sequence conservation and modeling studies suggest that HIV-2 RNA forms the same structure. We conclude that, like the main sub-groups of HIV-1, SIV and HIV-2 utilize stable stem-loop structures to function as a thermodynamic barrier to translation, thereby inducing ribosomal pausing and frameshifting. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Programmed | + | Programmed ribosomal frameshifting in SIV is induced by a highly structured RNA stem-loop., Marcheschi RJ, Staple DW, Butcher SE, J Mol Biol. 2007 Oct 26;373(3):652-63. Epub 2007 Aug 22. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17868691 17868691] |
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Butcher, S | + | [[Category: Butcher, S E.]] |
| - | [[Category: Marcheschi, R | + | [[Category: Marcheschi, R J.]] |
| - | [[Category: Staple, D | + | [[Category: Staple, D W.]] |
[[Category: frameshifting]] | [[Category: frameshifting]] | ||
[[Category: hiv-2]] | [[Category: hiv-2]] | ||
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[[Category: triloop]] | [[Category: triloop]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:05:47 2008'' |
Revision as of 16:05, 21 February 2008
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Solution Structure of the Frameshift-Inducing RNA Stem-Loop in SIV
Overview
Simian immunodeficiency virus (SIV), like its human homologues (HIV-1, HIV-2), requires a -1 translational frameshift event to properly synthesize all of the proteins required for viral replication. The frameshift mechanism is dependent upon a seven-nucleotide slippery sequence and a downstream RNA structure. In SIV, the downstream RNA structure has been proposed to be either a stem-loop or a pseudoknot. Here, we report the functional, structural and thermodynamic characterization of the SIV frameshift site RNA. Translational frameshift assays indicate that a stem-loop structure is sufficient to promote efficient frameshifting in vitro. NMR and thermodynamic studies of SIV RNA constructs of varying length further support the absence of any pseudoknot interaction and indicate the presence of a stable stem-loop structure. We determined the structure of the SIV frameshift-inducing RNA by NMR. The structure reveals a highly ordered 12 nucleotide loop containing a sheared G-A pair, cross-strand adenine stacking, two G-C base-pairs, and a novel CCC triloop turn. The loop structure and its high thermostability preclude pseudoknot formation. Sequence conservation and modeling studies suggest that HIV-2 RNA forms the same structure. We conclude that, like the main sub-groups of HIV-1, SIV and HIV-2 utilize stable stem-loop structures to function as a thermodynamic barrier to translation, thereby inducing ribosomal pausing and frameshifting.
About this Structure
2JTP is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Programmed ribosomal frameshifting in SIV is induced by a highly structured RNA stem-loop., Marcheschi RJ, Staple DW, Butcher SE, J Mol Biol. 2007 Oct 26;373(3):652-63. Epub 2007 Aug 22. PMID:17868691
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