2awv: Difference between revisions
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[[ | ==NMR Structural Analysis of the dimer of 5MCCTCATCC== | ||
<StructureSection load='2awv' size='340' side='right' caption='[[2awv]], [[NMR_Ensembles_of_Models | 1 NMR models]]' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2awv]] is a 2 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AWV OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2AWV FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MCY:5-METHYL-2-DEOXYCYTIDINE'>MCY</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1q2t|1q2t]], [[1rme|1rme]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2awv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2awv OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2awv RCSB], [http://www.ebi.ac.uk/pdbsum/2awv PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
At slightly acidic pH, the association of two d(5mCCTCACTCC) strands results in the formation of an i-motif dimer. Using NMR methods, we investigated the structure of [d(5mCCTCACTCC)]2, the internal motion of the base pairs stacked in the i-motif core, the dimer formation and dissociation kinetics versus pH. The excellent resolution of the 1H and 31P spectra provided the determination of dihedral angles, which together with a large set of distance restraints, improve substantially the definition of the sugar-phosphate backbone by comparison with previous NMR studies of i-motif structures. [d(5mCCTCACTCC)]2 is built by intercalation of two symmetrical hairpins held together by six symmetrical C*C+ pairs and by pair T7*T7. The hairpin loops that are formed by a single residue, A5, cross the narrow grooves on the same side of the i-motif core. The base pair intercalation order is C9*C9+/5mC1*5mC1+/C8*C8+/C2*C2+/T7.T7/C6*C6+/C4*C4+. The T3 bases are flipped out in the wide grooves. The core of the structure includes four long-lived pairs whose lifetimes at 15 degrees C range from 100 s (C8*C8+) to 0.18 s (T7*T7). The formation rate and the lifetime of [d(5mCCTCACTCC)]2 were measured between pH 6.8 and 4.8. The dimer formation rate is three to four magnitude orders slower than that of a B-DNA duplex. It depends on pH, as it must occur for a bimolecular process involving non cooperative association of neutral and protonated residues. In the range of pH investigated, the dimer lifetime, 500 s at 0 degrees C, pH 6.8, varies approximately as 10(-pH). | |||
Structure, internal motions and association-dissociation kinetics of the i-motif dimer of d(5mCCTCACTCC).,Canalia M, Leroy JL Nucleic Acids Res. 2005 Oct 4;33(17):5471-81. Print 2005. PMID:16204453<ref>PMID:16204453</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
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[[Category: Canalia, M.]] | [[Category: Canalia, M.]] | ||
[[Category: Leroy, J L.]] | [[Category: Leroy, J L.]] | ||
