Salt Dependence of the Radius of Gyration and Flexibility of Single-stranded DNA in Solution probed by Small-angle X-ray Scattering

Journal Article · Fri Jul 06 04:00:00 EDT 2012 · Submitted to Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevE.86.021901· OSTI ID:1045181

Sim, Adelene Y.L.; Lipfert, Jan; Herschlag, Daniel; Doniach, Sebastian

Short single-stranded nucleic acids are ubiquitous in biological processes and understanding their physical properties provides insights to nucleic acid folding and dynamics. We used small angle x-ray scattering to study 8-100 residue homopolymeric single-stranded DNAs in solution, without external forces or labeling probes. Poly-T's structural ensemble changes with increasing ionic strength in a manner consistent with a polyelectrolyte persistence length theory that accounts for molecular flexibility. For any number of residues, poly-A is consistently more elongated than poly-T, likely due to the tendency of A residues to form stronger base-stacking interactions than T residues.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: US DOE Office of Science (DOE SC); Basic Energy Sciences (BES)
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1045181
• Report Number(s): SLAC-PUB-15151
• Journal Information: Submitted to Physical Review Letters, Journal Name: Submitted to Physical Review Letters
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
DNA
FLEXIBILITY
NUCLEIC ACIDS
PHYSICAL PROPERTIES
PROBES
RESIDUES
SMALL ANGLE SCATTERING
XFEL