Open AccessThe sequence (dC-dA)n X (dG-dT)n forms left-handed Z-DNA in negatively supercoiled plasmids.
Author(s) -
Alfred Nordheim,
Alexander Rich
Publication year - 1983
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.80.7.1821
Subject(s) - dna supercoil , z dna , plasmid , dna , chromatin , microbiology and biotechnology , biology , dna sequencing , genome , chemistry , genetics , gene , dna replication
Z-DNA-specific antibodies have been used to demonstrate the formation of left-handed Z-DNA in sequences of (dC-dA)32 X (dG-dT)32 in negatively supercoiled plasmids. Z-DNA was found to form at physiological negative superhelical densities (sigma = -0.05) in the absence of high salt concentration or chemical modifications. The binding site of the antibody to the DNA sequences was demonstrated by crosslinking experiments. (dC-dA)n X (dG-dT)n sequences are widespread in eukaryotic DNA, and possible roles for such Z elements in chromatin activation or genome rearrangements are suggested.