Specificity of the antibodies raised against the reverse gyrases of S. solfataricus . Western blot analysis of recombinant proteins TopR1 and TopR2 of S. solfataricus in lanes 1 and 2, respectively, and of S. solfataricus crude extracts in lane 3. Lanes 1-3 were probed with either anti-TopR1 serum diluted 1/6000 (A) or anti-TopR2 serum diluted 1/4000 (B). Molecular weight standards in kDa (Kaleidoscope, BioRad) are indicated near panels A and B. Lanes 1 in panels A and B contain 0.3 ng and 50 ng of the recombinant TopR1, respectively. Lanes 2 in panels A and B correspond to 50 ng of the recombinant TopR2. Lane 3 in panel A and lane 3 in panel B contain 10 μg and 50 μg of S. solfataricus crude extracts, respectively. Asterisks indicate the signals for TopR1 and TopR2 in crude extracts.