Opposing Effects of Multivalent Ions on the Flexibility of DNA and RNA
| Autor: | Alexey V. Onufriev, Aleksander Drozdetski, Lois Pollack, Igor S. Tolokh, Nathan A. Baker |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Polymers General Physics and Astronomy Bending 010402 general chemistry 01 natural sciences Article Biophysical Phenomena 03 medical and health sciences chemistry.chemical_compound Molecular dynamics Molecule RNA Double-Stranded Ions chemistry.chemical_classification Persistence length Base Sequence Chemistry Ionic atmosphere RNA DNA Polymer 0104 chemical sciences 030104 developmental biology Chemical physics |
| Zdroj: | Physical Review Letters. 117 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | Increasing the concentration of counterions (salt) is known to reduce the bending persistence length of DNA. Here we use atomistic molecular dynamics simulations to predict that multivalent counterions have the opposite effect on double-stranded RNA, increasing its bending rigidity by at least 30%. This counterintuitive effect is observed for various tri- and tetravalent ions alike, and is robust to methodological details and the RNA sequence. In contrast to DNA, multivalent counterions bind inside the RNA major groove, causing significant contraction of the molecule along its helical axis-as a result, its further deformation due to bending becomes energetically more expensive compared to bending without bound multivalent ions. Thus, the relationship between mechanical properties of a charged polymer and its ionic atmosphere may be richer than previously thought. |
| Databáze: | OpenAIRE |
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