283d

[[Image:283d.jpg|left|200px]]<br /><applet load="283d" size="350" color="white" frame="true" align="right" spinBox="true"

caption="283d, resolution 2.300&Aring;" />

'''A CURVED RNA HELIX INCORPORATING AN INTERNAL LOOP WITH G-A AND A-A NON-WATSON-CRICK BASE PAIRING'''<br />

==Overview==

The crystal structure of the RNA dodecamer 5'-GGCC(GAAA)GGCC-3' has been, determined from x-ray diffraction data to 2.3-A resolution. In the, crystal, these oligomers form double helices around twofold symmetry axes., Four consecutive non-Watson-Crick base pairs make up an internal loop in, the middle of the duplex, including sheared G.A pairs and novel asymmetric, A.A pairs. This internal loop sequence produces a significant curvature, and narrowing of the double helix. The helix is curved by 34 degrees from, end to end and the diameter is narrowed by 24% in the internal loop. A, Mn2+ ion is bound directly to the N7 of the first guanine in the, Watson-Crick region following the internal loop and the phosphate of the, preceding residue. This Mn2+ location corresponds to a metal binding site, observed in the hammerhead catalytic RNA.

 

==About this Structure==

283D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=283D OCA].

 

A curved RNA helix incorporating an internal loop with G.A and A.A non-Watson-Crick base pairing., Baeyens KJ, De Bondt HL, Pardi A, Holbrook SR, Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):12851-5. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8917508 8917508]

[[Category: Baeyens, K.J.]]

[[Category: Bondt, H.L.De.]]

[[Category: Holbrook, S.R.]]

[[Category: curved]]

[[Category: double helix]]

[[Category: internal loop]]

[[Category: mismatched]]

[[Category: unusual rna]]