Sequence dependent rigidity of single stranded DNA.
Phys Rev Lett
; 85(11): 2400-3, 2000 Sep 11.
Article
in En
| MEDLINE
| ID: mdl-10978020
ABSTRACT
Single stranded DNA (ssDNA) equilibrium dynamics are investigated using a fluorophore/quencher-labeled hairpin structure which thermally fluctuates between open and closed states. Temporal correlations of the fluorescence fluctuations are used to determine the energy barrier to conformational change. We find that ssDNA distortion is purely entropic for poly(T) but requires an additional enthalpy of +0.5 kcal x mol(-1) x base(-1) for poly(A), consistent with the disruption of base stacking. Such sequence dependent dynamics challenge the classical model of ssDNA as a completely flexible coil.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
DNA, Single-Stranded
Language:
En
Journal:
Phys Rev Lett
Year:
2000
Document type:
Article
Affiliation country:
Estados Unidos