Distance-dependent duplex DNA destabilization proximal to G-quadruplex/i-motif sequences

摘要: G-quadruplexes and i-motifs are complementary examples of non-canonical nucleic acid substructure conformations. G-quadruplex thermodynamic stability has been extensively studied for a variety base sequences, but the degree duplex destabilization that adjacent quadruplex structure formation can cause yet to be fully addressed. Stable in vivo these alternative structures is likely highly dependent on whether sufficient spacing exists between neighbouring duplex- quadruplex-/i-motif-forming regions accommodate quadruplexes or without disrupting stability. Prediction putative G-quadruplex-forming assisted by further understanding what distance (number pairs) required duplexes remain stable as form. Using oligonucleotide constructs derived from precedented i-motif-forming bcl-2 P1 promoter region, initial biophysical studies indicate i-motif conformations do destabilize proximal regions. The undermining effect have mitigated with increased region: five pairs more maintain predicted quadruplex/i-motif-forming