Fig. 2.

TDRD3 demonstrates retention of negative supercoiling in plasmid substrates. (A) Addition of TDRD3 generates final products with greater linking number deficiency than control reactions without TDRD3. The extent of negative supercoiling retention was manifested by using different concentrations of EtBr. Final reaction products were analyzed in the presence of chloroquine to distinguish differences in negative supercoiling densities (−, reaction was stopped immediately after Top1 incubation). (B) TDRD3 generates final products with linking number deficiency from Top1-relaxed pUC19 DNA, compared with control reactions with Top1 only. The extent of supercoiling retention was dependent on TDRD3 concentrations. (N, negatively supercoiled substrates; T3, 2 µM TDRD3 without Top1.)