ABSTRACT Non-B DNA structures represent alternative conformations to the canonical double helix, characterized by unconventional base pairing that diverge from the Watson-Crick model. Among these, the i-motifs, formed in cytosine-rich regions, has attracted considerable attention due to its potential regulatory roles. This review examines the molecular mechanisms underlying the formation and stability of i-motifs, which rely on hydrogen bonding between protonated cytosines. These structures can form under slightly acidic and even neutral pH conditions, depending on the DNA sequence context. […]
