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

• Ngôn ngữ: eng
• Ký hiệu phân loại: 577.2 Specific factors affecting ecology
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2012
• Mô tả vật lý: Size: 19 pages : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 262248
• Chủ đề: 1. 59 basic biological sciences; 2. 60 applied life sciences; 3. Dna; 4. Flexibility; 5. Nucleic acids; 6. Physical properties; 7. Probes; 8. Residues; 9. Small angle scattering; 10. Xfel

Tóm tắt

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.