438d
From Proteopedia
(New page: 200px<br /><applet load="438d" size="350" color="white" frame="true" align="right" spinBox="true" caption="438d, resolution 2.50Å" /> '''STRUCTURE OF AN RNA ...) |
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==Overview== | ==Overview== | ||
| - | The crystal structure of a self-complementary RNA duplex r(GGGCGCUCC)2with | + | The crystal structure of a self-complementary RNA duplex r(GGGCGCUCC)2with non-adjacent G*U and U*G wobble pairs separated by four Watson-Crick base pairs has been determined to 2.5 A resolution. Crystals belong to the space group R3; a = 33.09 A,alpha = 87.30 degrees with a pseudodyad related duplex in the asymmetric unit. The structure was refined to a final Rworkof 17.5% and Rfreeof 24.0%. The duplexes stack head-to-tail forming infinite columns with virtually no twist at the junction steps. The 3'-terminal cytosine nucleosides are disordered and there are no electron densities, but the 3' penultimate phosphates are observed. As expected, the wobble pairs are displaced with guanine towards the minor groove and uracil towards the major groove. The largest twist angles (37.70 and 40.57 degrees ) are at steps G1*C17/G2*U16 and U7*G11/C8*G10, while the smallest twist angles (28.24 and 27.27 degrees ) are at G2*U16/G3*C15 and C6*G12/U7*G11 and conform to the pseudo-dyad symmetry of the duplex. The molecule has two unequal kinks (17 and 11 degrees ) at the wobble sites and a third kink at the central G5 site which may be attributed to trans alpha (O5'-P), trans gamma (C4'-C5') backbone conformations. The 2'-hydroxyl groups in the minor groove form inter-column hydrogen bonding, either directly or through water molecules. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Shi, K.]] | [[Category: Shi, K.]] | ||
[[Category: Sundaralingam, M.]] | [[Category: Sundaralingam, M.]] | ||
| - | [[Category: Wahl, M | + | [[Category: Wahl, M C.]] |
[[Category: a-rna]] | [[Category: a-rna]] | ||
[[Category: double helix]] | [[Category: double helix]] | ||
[[Category: mismatched]] | [[Category: mismatched]] | ||
| - | ''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 19:12:11 2008'' |
Revision as of 17:12, 21 February 2008
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STRUCTURE OF AN RNA DUPLEX R(GGGCGCUCC)2 WITH NON-ADJACENT G.U BASE PAIRS
Overview
The crystal structure of a self-complementary RNA duplex r(GGGCGCUCC)2with non-adjacent G*U and U*G wobble pairs separated by four Watson-Crick base pairs has been determined to 2.5 A resolution. Crystals belong to the space group R3; a = 33.09 A,alpha = 87.30 degrees with a pseudodyad related duplex in the asymmetric unit. The structure was refined to a final Rworkof 17.5% and Rfreeof 24.0%. The duplexes stack head-to-tail forming infinite columns with virtually no twist at the junction steps. The 3'-terminal cytosine nucleosides are disordered and there are no electron densities, but the 3' penultimate phosphates are observed. As expected, the wobble pairs are displaced with guanine towards the minor groove and uracil towards the major groove. The largest twist angles (37.70 and 40.57 degrees ) are at steps G1*C17/G2*U16 and U7*G11/C8*G10, while the smallest twist angles (28.24 and 27.27 degrees ) are at G2*U16/G3*C15 and C6*G12/U7*G11 and conform to the pseudo-dyad symmetry of the duplex. The molecule has two unequal kinks (17 and 11 degrees ) at the wobble sites and a third kink at the central G5 site which may be attributed to trans alpha (O5'-P), trans gamma (C4'-C5') backbone conformations. The 2'-hydroxyl groups in the minor groove form inter-column hydrogen bonding, either directly or through water molecules.
About this Structure
438D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Crystal structure of an RNA duplex r(G GCGC CC)2 with non-adjacent G*U base pairs., Shi K, Wahl M, Sundaralingam M, Nucleic Acids Res. 1999 May 15;27(10):2196-201. PMID:10219093
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