Direct Observation of Multiple Pathways of Single-Stranded DNA Stretching
Open Access
- 19 November 2010
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 105 (21)
- https://doi.org/10.1103/physrevlett.105.218104
Abstract
We observed multiple pathways of stretching single-stranded polydeoxynucleotides, poly(dA). Poly(dA) has been shown to undergo unique transitions under mechanical force, and such transitions were attributed to the stacking characteristics of poly(dA). Using single-molecule manipulation studies, we found that poly(dA) has two stretching pathways at high forces. The previously observed pathway has a free energy that is less than what is expected of single-stranded DNA with a random sequence, indicating the existence of a novel conformation of poly(dA) at large extensions. We also observed stepwise transitions between the two pathways by pulling the molecule with constant force, and found that the transitions are cooperative. These results suggest that the unique mechanical property of poly(dA) may play an important role in biological processes such as gene expression.Keywords
This publication has 44 references indexed in Scilit:
- The structure of DNA overstretched from the 5′5′ ends differs from the structure of DNA overstretched from the 3′3′ endsProceedings of the National Academy of Sciences of the United States of America, 2009
- In the absence of writhe, DNA relieves torsional stress with localized, sequence-dependent structural failure to preserve B-formNucleic Acids Research, 2009
- Reverse DNA translocation through a solid-state nanopore by magnetic tweezersNanotechnology, 2009
- Quantifying DNA melting transitions using single-molecule force spectroscopyJournal of Physics: Condensed Matter, 2008
- Solvent molecules bridge the mechanical unfolding transition state of a proteinProceedings of the National Academy of Sciences of the United States of America, 2008
- Using theory and computation to model nanoscale propertiesProceedings of the National Academy of Sciences of the United States of America, 2007
- Influence of secondary structure on kinetics and reaction mechanism of DNA hybridizationNucleic Acids Research, 2007
- Probing Single-Stranded DNA Conformational Flexibility Using Fluorescence SpectroscopyBiophysical Journal, 2004
- Length and Statistical Weight of Bubbles in DNA MeltingPhysical Review Letters, 2003
- Entropic Elasticity of λ-Phage DNAScience, 1994