1i9k
From Proteopedia
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|PDB= 1i9k |SIZE=350|CAPTION= <scene name='initialview01'>1i9k</scene> | |PDB= 1i9k |SIZE=350|CAPTION= <scene name='initialview01'>1i9k</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=C:CYTIDINE-5'-MONOPHOSPHATE'>C</scene>, <scene name='pdbligand=U:URIDINE-5'-MONOPHOSPHATE'>U</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1i9k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i9k OCA], [http://www.ebi.ac.uk/pdbsum/1i9k PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1i9k RCSB]</span> | ||
}} | }} | ||
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[[Category: rna]] | [[Category: 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 21:16:35 2008'' |
Revision as of 18:16, 30 March 2008
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| Ligands: | , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
THE RNA I-MOTIF
Overview
Oligodeoxynucleotides with stretches of cytidine residues associate into a four-stranded structure, the i-motif, in which two head-to-tail, intercalated, parallel-stranded duplexes are held together by hemiprotonated C.C+ pairs. We have investigated the possibility of forming an i-motif structure with C-rich ribonucleic acids. The four C-rich RNAs studied, r(UC5), r(C5), r(C5U) and r(UC3), associate into multiple intercalated structures at acidic pH. r(UC5) forms two i-motif structures that differ by their intercalation topologies. We report on a structural study of the main form and we analyze the small conformational differences found by comparison with the DNA i-motif. The stacking topology of the main structure avoids one of the six 2'-OH/2'-OH repulsive contacts expected in a fully intercalated structure. The C3'-endo pucker of the RNA sugars and the orientation of the intercalated C.C+ pairs result in a modest widening of the narrow grooves at the steps where the hydroxyl groups are in close contact. The free energy of the RNA i-motif, on average -4 kJ mol(-1) per C.C+ pair, is half of the value found in DNA i-motif structures.
About this Structure
1I9K is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
The RNA i-motif., Snoussi K, Nonin-Lecomte S, Leroy JL, J Mol Biol. 2001 May 25;309(1):139-53. PMID:11491284
Page seeded by OCA on Sun Mar 30 21:16:35 2008
Categories: Protein complex | Lerou, J L. | Nonin-Lecomte, S. | Snoussi, K. | I-motif | Nmr | Rna
