Figure 4.

The effect of MalE-MinC on FtsZ polymerization. (A and B) Polymerization reactions (100 μl) were carried out with FtsZ (5 μM) in polymerization buffer and increasing concentrations of MalE-MinC (A) or MalE (B). Polymerization was initiated with the addition of 1 mM GTP, samples were centrifuged, and the pellets were analyzed by SDS/PAGE. A shows the effect of MalE-MinC: lane 1, GDP added; lane 2, GTP added served as controls. The concentrations of MalE-MinC were, by lanes: 3, 50 μg/ml (0.75 μM); 4, 100 μg/ml (1.5 μM); 5, 200 μg/ml (3 μM); 6, 400 μg/ml (6 μM); 7, 800 μg/ml (12 μM); 8, 1200 μg/ml (18 μM); (B) As A except that MalE was added instead of MalE-MinC. The concentrations (in μg/ml) were the same as in A. (C–E) Samples were also taken 10 min after GTP addition and were examined by electron microscopy. C contained FtsZ alone (5 μM); D contained FtsZ (5 μM) with 3 μM (200 μg/ml) of MalE-MinC; E contained FtsZ (5 μM) and MalE at 200 μg/ml; and F contained FtsZ (5 μM) and MalE-MinC19 at 200 μg/ml).