. "superhelical" . "plasmid DNA" . "superhelical stress" . . "Supercoiled" . "DNA supercoil" . "supercoiling" . "superhelical density" . . "supercoiled DNA" . "supercoil" . "supercoils" . "supercoiled plasmid DNA" . "\u2018permanently super-coiled\u2019 DNA" . "supercoiled" . "negative supercoils" . "DNA supercoil" . . "negatively supercoiled" . "DNA structural changes" . "DNA_supercoil#Mathematical_description" . "circular chromosome" . . "positively supercoiled" . .