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Publication Abstract from PubMed

The oligomer d(GCGTG3 TCAG3 TG3 TG3 ACGC) with short complementary flanking sequences at the 5'- and 3'-ends was shown to fold into three different DNA G-quadruplex species. In contrast, a corresponding oligomer that lacks base complementarity between the two overhang sequences folds into a single parallel G-quadruplex. The three coexisting quadruplex structures were unambiguously identified and structurally characterized through detailed spectral comparisons with well-defined G-quadruplexes formed upon the deliberate incorporation of syn-favoring 8-bromoguanosine analogues into specific positions of the G-core. Two (3+1) hybrid structures coexist with the parallel fold and feature a novel lateral-propeller-propeller loop architecture that has not yet been confirmed experimentally. Both hybrid quadruplexes adopt the same topology and only differ in their pattern of anti-->syn transitions and tetrad stackings.

Duplex-Guided Refolding into Novel G-Quadruplex (3+1) Hybrid Conformations.,Karg B, Mohr S, Weisz K Angew Chem Int Ed Engl. 2019 May 28. doi: 10.1002/anie.201905372. PMID:31134741^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.