Complex structural behavior of oligopurine-ligopyrimidine sequence cloned within the supercoiled plasmid

Abstract
Synthetic sequence GATCC(AG)7ATCG(AT)4CG(AG)7 was cloned into plasmid and its structural behavior under the infuence of supercoiling was analysed by chemical modification at variety of experimental conditions. It was found that this sequence adopts at least two different non-B conformations depending on -.hivin..sigma. and pH values. Moreover, 12 nucleotide long non-pur .cntdot. pyr spacer region separating two identical (AG)7 blocks does not provide a significant energy barrier protecting against unusual structures formation.