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| [[Image:1d81.gif|left|200px]]<br /><applet load="1d81" size="450" color="white" frame="true" align="right" spinBox="true"
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| caption="1d81, resolution 2.500Å" />
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| '''THE CONFORMATIONAL VARIABILITY OF AN ADENOSINE. INOSINE BASE-PAIR IN A SYNTHETIC DNA DODECAMER'''<br />
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| ==Overview== | | ==THE CONFORMATIONAL VARIABILITY OF AN ADENOSINE. INOSINE BASE-PAIR IN A SYNTHETIC DNA DODECAMER== |
| A crystal structure analysis of the synthetic deoxydodecamer, d(CGCAAATTIGCG) which contains two adenosine.inosine (A.I) mispairs has, revealed that, in this sequence, the A.I base-pairs adopt a A(anti).I(syn), configuration. The refinement converged at R = 0.158 for 2004 reflections, with F greater than or equal to 2 sigma(F) in the range 7.0-2.5A for a, model consisting of the DNA duplex and 71 water molecules. A notable, feature of the structure is the presence of an almost complete spine of, hydration spanning the minor groove of the whole of the (AAATTI)2 core, region of the duplex. pH-dependent ultraviolet melting studies have, suggested that the base-pair observed in the crystal structure is, in, fact, a protonated AH+ (anti).I(syn) species and that the A.I base-pairs, in the sequence studied display the same conformational variability as A.G, mispairs in the sequence d(CGCAAATTGGCG). The AH+(anti).I(syn) base-pair, predominates below pH 6.5 and an A(anti).I(anti) mispair is the major, species present between pH 6.5 and 8.0. The protonated base-pairs are held, together by two hydrogen bonds one between N6(A) and O6(I) and the other, between N1(A) and N7(I). This second hydrogen bond is a direct result of, the protonation of the N1 of adenosine. The ultraviolet melting studies, indicate that the A(anti).I(anti) base-pair is more stable than the, A(anti).G(anti) base-pair but that the AH+(anti).I(syn) base pair is less, stable than its AH+(anti).G(syn) analogue. Possible reasons for this, observation are discussed.
| | <StructureSection load='1d81' size='340' side='right'caption='[[1d81]], [[Resolution|resolution]] 2.50Å' scene=''> |
| | | == Structural highlights == |
| ==About this Structure== | | <table><tr><td colspan='2'>[[1d81]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D81 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1D81 FirstGlance]. <br> |
| 1D81 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1D81 OCA].
| | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> |
| | | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1d81 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1d81 OCA], [https://pdbe.org/1d81 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1d81 RCSB], [https://www.ebi.ac.uk/pdbsum/1d81 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1d81 ProSAT]</span></td></tr> |
| ==Reference== | | </table> |
| The conformational variability of an adenosine.inosine base-pair in a synthetic DNA dodecamer., Leonard GA, Booth ED, Hunter WN, Brown T, Nucleic Acids Res. 1992 Sep 25;20(18):4753-9. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=1408788 1408788]
| | __TOC__ |
| [[Category: Protein complex]] | | </StructureSection> |
| [[Category: Booth, E.D.]]
| | [[Category: Large Structures]] |
| [[Category: Brown, T.]]
| | [[Category: Booth ED]] |
| [[Category: Hunter, W.N.]]
| | [[Category: Brown T]] |
| [[Category: Leonard, G.A.]] | | [[Category: Hunter WN]] |
| [[Category: b-dna]] | | [[Category: Leonard GA]] |
| [[Category: double helix]] | |
| [[Category: mismatched]] | |
| [[Category: modified]] | |
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| ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 02:42:35 2007''
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