Loop nucleotides impact the stability of intrastrand i-motif structures at neutral pH.

Loop nucleotides impact stability of intrastrand i-motif structures at neutral pH

Stabilities of intrastrand pyrimidine motif DNA and RNA triple helices.

Nucleic acid triple helices have provoked interest since their discovery more than 40 years ago, but it remains unknown whether such structures occur naturally in cells. To pursue this question, it is important to determine the stabilities of representative triple helices at physiological temperature and pH. Previous investigations have concluded that while both DNA and RNA can participate in t...

Identification of multiple genomic DNA sequences which form i-motif structures at neutral pH

i-Motifs are alternative DNA secondary structures formed in cytosine-rich sequences. Particular examples of these structures, traditionally assumed to be stable only at acidic pH, have been found to form under near-physiological conditions. To determine the potential impact of these structures on physiological processes, investigation of sequences with the capacity to fold under physiological c...

I-Motif Structures Formed in the Human c-MYC Promoter Are Highly Dynamic–Insights into Sequence Redundancy and I-Motif Stability

The GC-rich nuclease hypersensitivity element III1 (NHE III1) of the c-MYC promoter largely controls the transcriptional activity of the c-MYC oncogene. The C-rich strand in this region can form I-motif DNA secondary structures. We determined the folding pattern of the major I-motif formed in the NHE III1, which can be formed at near-neutral pH. While we find that the I-motif formed in the four...

The importance of loop length on the stability of i-motif structures.

Using UV and srCD spectroscopy it is found that loop length within the i-motif structure is important for both thermal and pH stability, but in contrast to previous statements, it is the shorter loops that exhibit the highest stability.