Concentration effect of Dr-FtsA on sedimentation characteristic of Dr-FtsZ.

<p><b>A</b>. Purified recombinant Dr-FtsZ was incubated with increasing molar ratio of Dr-FtsA such as 1∶0.5 (3,4), 1∶1 (5,6) and 1∶2 (7,8) under standard assay conditions of Dr-FtsZ described elsewhere in this paper. Samples were spun at 150 000×g for 15 min at 37°C. Both pellet and supernatant fractions obtained were analysed on SDS-PAGE (upper panel) and protein bands corresponding to Dr-FtsZ (FtsZ) and Dr-FtsA (FtsA) were quantified densitometrically for samples numbered as 1-6 and presented as histogram (lower panel) <b>B</b>. Dr-FtsZ (1) was incubated with both 2 mM Mg²⁺ and 1 mM GTP (2, 3, 4) for 10 min and then purified Dr-FtsA was added in 1∶1 molar ratio and further incubated for another 10 min in the absence (3) and presence (4) of ATP. Samples (1–4) were spun at 22000×g for 1 h and corresponding pellet and supernatants were analysed on SDS-PAGE (upper panel). Density of FtsZ protein bands in these samples were plotted as histograms (lower panel).