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==SOLUTION STRUCTURE OF THE [AF]-C8-DG ADDUCT POSITIONED AT A TEMPLATE-PRIMER JUNCTION, NMR, 6 STRUCTURES==
<StructureSection load='1ax7' size='340' side='right'caption='[[1ax7]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ax7]] is a 2 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AX7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AX7 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AF:2-AMINOFLUORENE'>AF</scene></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=1ax7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ax7 OCA], [https://pdbe.org/1ax7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ax7 RCSB], [https://www.ebi.ac.uk/pdbsum/1ax7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ax7 ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
A solution structural study has been undertaken on the aminofluorene-C8-dG ([AF]dG) adduct located at a single strand-double strand d(A1-A2-C3-[AF]G4-C5-T6-A7-C8-C9-A10-T11-C12-C13).d (G14-G15-A16-T17-G18-G19-T20-A 21-G22) 13/9-mer junction (designated [AF]dG 13/9-mer) using proton-proton distance and intensity restraints derived from NMR data in combination with a computational protocol, which includes intensity refinement. This single strand-double strand junction models one arm of a replication fork composed of a 13-mer template strand, which contains the [AF]dG modification site, and a 9-mer primer strand, which has been elongated up to, but not including, the modified guanine. The NMR data establish that the duplex segment retains a minimally perturbed B-DNA conformation including Watson-Crick hydrogen-bonding at the junctional dC5.dG22 base pair. The NMR spectra are consistent with the guanine ring of the [AF]dG4 adduct adopting a syn glycosidic torsion angle and being displaced into the major groove with the adjacent dC3 residue displaced into the minor groove. Such a base displacement of the modified guanine is accompanied by stacking of one face of the fluorene ring of [AF]dG4 with the dC5.dG22 base pair, while the other face of the flourene ring is stacked with the purine ring of the nonadjacent dA2 residue in the intensity-refined solution structures of the [AF]dG 13/9-mer. A comparison of structural features of the C8-[AF]dG adduct (this study) with those of the (+)-trans-anti-N2-[BP]dG adduct [Cosman et al. (1995) Biochemistry 34, 15334-15350] in the same 13/9-mer junctional sequence context has identified common features associated with the alignment of the modified guanine adducts at the template-primer junction. Thus, despite differences in the covalent linkage site for the C8-[AF]dG and (+)-trans-anti-N2-[BP]dG adducts, one face of the aromatic ring of the carcinogen stacks over the junctional base pair and in so doing displaces the modified guanine in a syn alignment into the major groove. These results lend credence to earlier proposals that such an adduct alignment may represent a common mutagenic conformer at a template-primer junction associated with a replication fork.

Solution structure of the aminofluorene-stacked conformer of the syn [AF]-C8-dG adduct positioned at a template-primer junction.,Mao B, Gu Z, Gorin A, Hingerty BE, Broyde S, Patel DJ Biochemistry. 1997 Nov 25;36(47):14491-501. PMID:9398168<ref>PMID:9398168</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Broyde S]]
[[Category: Gorin AA]]
[[Category: Gu Z]]
[[Category: Hingerty BE]]
[[Category: Mao B]]
[[Category: Patel DJ]]