Summary information and primary citation

6r9k; DSSR-derived features in text and JSON formats
A quadruplex hybrid structure with lpp loop orientation and 3 syn residues
Karg B, Mohr S, Weisz K (2019): "Duplex-Guided Refolding into Novel G-Quadruplex (3+1) Hybrid Conformations." Angew.Chem.Int.Ed.Engl., 58, 11068-11071. doi: 10.1002/anie.201905372.
The DNA sequence d(GCGTG₃TCAG₃TG₃TG₃ACGC) with short complementary flanking sequences at 5'- and 3'-ends was shown to fold into three different quadruplex species. In contrast, a corresponding sequence that lacks base complementarity between the two overhang sequences folds into a single parallel G-quadruplex. The three coexisting quadruplex structures can unambiguously be identified and structurally characterized through detailed spectral comparisons with well-defined G-quadruplexes formed upon the deliberate incorporation of syn-favoring 8-bromoguanosine analogs 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 verified experimentally. Both hybrid quadruplexes adopt the same topology and only differ in their pattern of anti→syn transitions and tetrad stackings.

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