Comprehensive Analysis of Stability and Variability of DNA Minimal I-Motif Structures.

ABSTRACT: Cytosine-rich DNA sequences form i-motif structures associated with various cellular functions including gene regulation. DNA sequences containing consecutive C residues are widely deemed essential for i-motif formation; however, some sequences lacking C-tracts have been reported to form minimal i-motif structures. We systematically investigated the variability in the minimal i-motif-forming DNA sequence comprising two TCGTTCCGT sequence units, which forms two C:C⁺ pairs and two G:C:G:T base tetrads. A comprehensive analysis of structural stability by DNA thermal melting temperature measurements revealed that oligonucleotides disrupting the formation of the base tetrad or its stacking interactions with a C:C⁺ pair prevent stable i-motif formation, and modifications to

SUBMITTER: Ashida K 

PROVIDER: S-EPMC12029255 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature