Abstract

The effect of superhelical stress to induce new global secondary structures and different tertiary conformations in circular DNAs is studied using a variety of techniques. Secondary structure governs the torsional rigidity of the filament and is studied via the time-resolved fluorescence polarization anisotropy of intercalated ethidium, dynamic light scattering and circular dichroism. Tertiary structure is monitored by both gel electrophoresis and dynamic and static light scattering. The existence and number of distinct secondary structures induced by changes in buffer, and their responses to temperature, intercalator concentration, and pH are examined. The influence of a 48 bp inverted repeat on both secondary and tertiary structures is also investigated. The effects of certain proteins, including single-strand binding protein and CAO protein from E. coli and antibodies specific for Z-helix, on the secondary and tertiary structures of supercoiled DNAs are also investigated.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM029338-04A1
Application #
3276890
Study Section
Biophysics and Biophysical Chemistry A Study Section (BBCA)
Project Start
1981-07-01
Project End
1988-11-30
Budget Start
1985-12-01
Budget End
1986-11-30
Support Year
4
Fiscal Year
1986
Total Cost
Indirect Cost

  Institution

Name
University of Washington
Department
Type
Schools of Arts and Sciences
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195

  Publications

Wu, P G; Fujimoto, B S; Song, L et al. (1991) Effect of ethidium on the torsion constants of linear and supercoiled DNAs. Biophys Chem 41:217-36
Song, L; Fujimoto, B S; Wu, P G et al. (1990) Evidence for allosteric transitions in secondary structure induced by superhelical stress. J Mol Biol 214:307-26
Wu, P G; Song, L; Schurr, J M (1990) Intramolecular interference effects in dynamic light scattering: rigid double spirals and superhelical DNAs. Biopolymers 29:1211-32
Wu, P; Schurr, J M (1989) Effects of chloroquine on the torsional dynamics and rigidities of linear and supercoiled DNAs at low ionic strength. Biopolymers 28:1695-703
Wu, P G; Song, L; Clendenning, J B et al. (1988) Interaction of chloroquine with linear and supercoiled DNAs. Effect on the torsional dynamics, rigidity, and twist energy parameter. Biochemistry 27:8128-44
Shibata, J H; Fujimoto, B S; Schurr, J M (1985) Rotational dynamics of DNA from 10(-10) to 10(-5) seconds: comparison of theory with optical experiments. Biopolymers 24:1909-30
Langowski, J; Benight, A S; Fujimoto, B S et al. (1985) Change of conformation and internal dynamics of supercoiled DNA upon binding of Escherichia coli single-strand binding protein. Biochemistry 24:4022-8
Schurr, J M; Schurr, R L (1985) DNA motions in the nucleosome core particle: a reanalysis. Biopolymers 24:1931-40
Vasmel, H (1985) Influence of supercoiling on DNA structure: laser Raman spectroscopy of the plasmid pBR322. Biopolymers 24:1001-8
Langowski, J; Fujimoto, B S; Wemmer, D E et al. (1985) Deformational dynamics and NMR relaxation of supercoiled DNAs. Biopolymers 24:1023-56