Figure 1.

(A) Schematic diagram showing the domain architecture of TopR1 and the two separate domains. The positions of the essential residues K116 in the catalytic site of the ATPase domain and Y965 in the topoisomerase domain are indicated by an arrow; the predicted Zn-finger motives and the region corresponding to the ‘latch’ in the A. fulgidus reverse gyrase are shown by internal boxes. (B) Coomassie-stained gel of purified TopR1 (1 μg), Cter and Nter (500 ng each). Fainter bands correspond to degradation products. M, molecular weight marker (kDa).