Remodeling the conformational dynamics of I-motif DNA by helicases in ATP-independent mode at acidic environment

• DOI: 10.1016/j.isci.2021.103575
• Publication Date: 2021-12-06T07:00:16Z
• Authors: Bo Gao; Ya-Ting Zheng; Ai-Min Su; Bo Sun; Xu-Guang Xi; Xi-Miao Hou
• Keywords: Single-molecule FRET; Sequence motif; Folding (DSP implementation); Structural motif

I-motifs are noncanonical four-stranded DNA structures formed by C-rich sequences at acidic environment with critical biofunctions. The particular pH sensitivity has inspired the development of i-motifs as sensors and motors in nanotechnology. However, folding regulation mechanisms remain elusive. Here, using single-molecule FRET, we first show that more dynamic than G4s. Impressively, display a high diversity six species slow interconversion. Further results indicate can be linearized Replication protein A. More importantly, identified number helicases specificity to low pH. All these directly act on efficiently resolve into intermediates independent ATP, although they poorly unwind G4 or duplex Owing extreme no need for i-motif may applied probe helicase sensing both vitro vivo.