1t4x
From Proteopedia
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|PDB= 1t4x |SIZE=350|CAPTION= <scene name='initialview01'>1t4x</scene> | |PDB= 1t4x |SIZE=350|CAPTION= <scene name='initialview01'>1t4x</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=C:CYTIDINE-5'-MONOPHOSPHATE'>C</scene>, <scene name='pdbligand=G:GUANOSINE-5'-MONOPHOSPHATE'>G</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1t4x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1t4x OCA], [http://www.ebi.ac.uk/pdbsum/1t4x PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1t4x RCSB]</span> | ||
}} | }} | ||
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[[Category: z-rna]] | [[Category: z-rna]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:51:22 2008'' |
Revision as of 20:51, 30 March 2008
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| Ligands: | , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
The first left-handed RNA structure of (CGCGCG)2, Z-RNA, NMR, 12 structures, determined in high salt
Overview
Right-handed RNA duplexes of (CG)n sequence undergo salt-induced helicity reversal, forming left-handed RNA double helices (Z-RNA). In contrast to the thoroughly studied Z-DNA, no Z-RNA structure of natural origin is known. Here we report the NMR structure of a half-turn, left-handed RNA helix (CGCGCG)2 determined in 6 M NaClO4. This is the first nucleic acid motif determined at such high salt. Sequential assignments of non-exchangeable proton resonances of the Z-form were based on the hitherto unreported NOE connectivity path [H6(n)-H5'/H5(n)-H8(n+1)-H1'(n+1)-H6(n+2)] found for left-handed helices. Z-RNA structure shows several conformational features significantly different from Z-DNA. Intra-strand but no inter-strand base stacking was observed for both CpG and GpC steps. Helical twist angles for CpG steps have small positive values (4-7 degrees), whereas GpC steps have large negative values (-61 degrees). In the full-turn model of Z-RNA (12.4 bp per turn), base pairs are much closer to the helix axis than in Z-DNA, thus both the very deep, narrow minor groove with buried cytidine 2'-OH groups, and the major groove are well defined. The 2'-OH group of cytidines plays a crucial role in the Z-RNA structure and its formation; 2'-O-methylation of cytidine, but not of guanosine residues prohibits A to Z helicity reversal.
About this Structure
1T4X is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
High salt solution structure of a left-handed RNA double helix., Popenda M, Milecki J, Adamiak RW, Nucleic Acids Res. 2004 Aug 3;32(13):4044-54. Print 2004. PMID:15292450
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