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1t4x
From Proteopedia
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[[Image:1t4x.gif|left|200px]] | [[Image:1t4x.gif|left|200px]] | ||
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'''The first left-handed RNA structure of (CGCGCG)2, Z-RNA, NMR, 12 structures, determined in high salt''' | '''The first left-handed RNA structure of (CGCGCG)2, Z-RNA, NMR, 12 structures, determined in high salt''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T4X OCA]. | |
==Reference== | ==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:[http://www.ncbi.nlm.nih.gov/pubmed/15292450 15292450] | 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:[http://www.ncbi.nlm.nih.gov/pubmed/15292450 15292450] | ||
| - | [[Category: Protein complex]] | ||
[[Category: Adamiak, R W.]] | [[Category: Adamiak, R W.]] | ||
[[Category: Milecki, J.]] | [[Category: Milecki, J.]] | ||
[[Category: Popenda, M.]] | [[Category: Popenda, M.]] | ||
| - | [[Category: | + | [[Category: Left-handed rna duplex]] |
| - | [[Category: | + | [[Category: Z-rna]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 09:32:05 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 06:32, 3 May 2008
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
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 Page seeded by OCA on Sat May 3 09:32:05 2008
