FIG. 1.

Purification of TraC. Coomassie-stained SDS-polyacrylamide gel showing steps leading to purification of TraC from an overexpressing strain. Lanes: 1 to 3, pTrcTraC-carrying strains JM109 before (lane 1) and after induction with IPTG for 45 (lane 2) and 90 min (lane 3); 4, supernatant resulting from extraction of the periplasm with Triton X-100-containing buffer; 5, 40 to 50% ammonium sulfate precipitation; 6, Mono Q anion-exchange chromatography; 7, Superdex 75 gel filtration chromatography. In all figures, positions of size standards are indicated in kilodaltons.