View source for 464d

[[Image:464d.gif|left|200px]]<br /><applet load="464d" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="464d, resolution 1.23&Aring;" />
'''DISORDER AND TWIN REFINEMENT OF RNA HEPTAMER DOUBLE HELIX'''<br />

==Overview==
An RNA helix with seven base pairs which was derived from the acceptor, stem of Escherichia coli tRNA(Ala), rGGGGCUA.rUAGCUCC (ALA(wt)), as well, as a variant, rGGGGCUA.rUAGCCCC (ALA(C70)), in which the single G.U wobble, base pair of ALA(wt) was replaced by G.C, crystallize in space group C2., Both non-isomorphic crystal forms display a complex packing pattern, which, can be described alternatively as disorder or pseudo-merohedral twinning., The structure of ALA(wt) was determined by SIRAS phasing using an, isomorphous iodine derivative, rGGGGCi(5)UA.rUAGCUCC (ALA(I)). All three, RNA structures were subsequently subjected to twin refinement in space, group P1, using anisotropic thermal displacement parameters at resolutions, of 1.16, 1.23 and 1.4 A for ALA(wt), ALA(I) and ALA(C70), respectively., Alternatively, the structure of ALA(wt) was refined in space group C2, assuming twofold disorder of the molecular orientation. The refined, structures are of reasonable quality according to all available, indicators. There are no systematic differences between the molecular, models resulting from twin refinement and disorder refinement.

==About this Structure==
464D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=SR:'>SR</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=464D OCA]. 

==Reference==
Disorder and twin refinement of RNA heptamer double helices., Mueller U, Muller YA, Herbst-Irmer R, Sprinzl M, Heinemann U, Acta Crystallogr D Biol Crystallogr. 1999 Aug;55(Pt 8):1405-13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10417408 10417408]
[[Category: Protein complex]]
[[Category: Heinemann, U.]]
[[Category: Herbst-Irmer, R.]]
[[Category: Mueller, U.]]
[[Category: Muller, Y.A.]]
[[Category: Sprinzl, M.]]
[[Category: NA]]
[[Category: SR]]
[[Category: 7 base-pair trna ala acceptor stem]]
[[Category: disordered model]]
[[Category: double helix]]
[[Category: ribonucleic acid]]

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