title: Conformational DNA transition in the in vitro torsionally strained chicken beta-globin 5' region.
abstract: A sequence of 86 bp within the 5' region of the adult chicken beta-globin gene was found to undergo a DNA conformational transition at elevated levels of negative superhelical stress (- sigma = 0.068). In vitro chemical DNA modification studies which detect purine hyperreactivity (HR) to the alkylating agent diethyl pyrocarbonate (DEP) have identified this 86 bp long DEP-HR element. The DEP-HR element is composed of small, tandem segments with imperfect purine-pyrimidine alternations. Methylation of cytosines within GCGC sequences of the DEP-HR element facilitates this structural change. The binding of a monoclonal anti-Z-DNA antibody to the element has been revealed by chemical footprinting with DEP. These data suggest that the DEP-HR sequence can undergo a conformational transition to Z-DNA. It is unknown whether the conformational flexibility observed here occurs in vivo.
mesh_terms: D000818:Animals; D000906:Antibodies; D001483:Base Sequence; D002645:Chickens; D002872:Chromosome Deletion; D004247:DNA / Q000097:blood / Q000235:genetics*; D004912:Erythrocytes / Q000378:metabolism; D005796:Genes; D005914:Globins / Q000235:genetics*; D009690:Nucleic Acid Conformation; D010957:Plasmids
chemical_list: D000906:Antibodies; D005914:Globins; D004247:DNA