Hoogsteen base pairs proximal and distal to echinomycin binding sites on DNA
Forms of the DNA double helix containing non-Watson-Crick base-pairing have been discovered recently based on x-ray diffraction analysis of quionoxaline antibiotic-oligonucleotide complexes. In an effort to find evidence for Hoogsteen base-pairing at quinoxaline-binding sites in solution, chemical footprinting (differential cleavage reactivity) of echinomycin bound to DNA restriction fragments was examined. The authors report that purines (A>G) in the first and/or fourth base-pair positions of occupied echinomycin-binding sites are hyperreactive to diethyl pyrocarbonate. The correspondence of the solid-state data and the sites of diethyl pyrocarbonate hyperreactivity suggests that diethyl pyrocarbonate may be a sensitive reagent for the detection of Hoogsteen base-pairing in solution. Moreover, a 12-base-pair segment of alternating A-T DNA, which is 6 base pairs away from the nearest strong echinomycin-binding site, is also hyperreactive to diethyl pyrocarbonate in the presence of echinomycin. This hyperreactive segment may be an altered form of right-handed DNA that is entirely Hoogsteen base-paired.
- Research Organization:
- California Institute of Technology, Pasadena
- OSTI ID:
- 5877756
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:4; ISSN PNASA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COHERENT SCATTERING
CONFIGURATION INTERACTION
DAYS LIVING RADIOISOTOPES
DIFFRACTION
DNA
DNA-ASE
DRUGS
ENZYMES
ESTERASES
HYDROLASES
ISOTOPES
LIGHT NUCLEI
MOLECULAR STRUCTURE
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
RADIOISOTOPES
SCATTERING
X-RAY DIFFRACTION