FIG. 7.

TraM, IHF, and TraD also stimulate TraIΔN308 activity. The effect of additional proteins on oriT unwinding catalyzed by the truncated TraIΔN308 form of the protein was compared using conditions equivalent to those of previous assays with wild-type TraI. Reactions were initiated by addition of TraIΔN308 (52 nM). The increase in TraIΔN308 unwinding activity on the IR (•), NIC (▴), and G2028 (▪) substrates is presented as a function of auxiliary protein concentration. The relative enhancement due to addition of TraM (0 to 40 nM; as monomer) (A), IHF (0 to 200 nM; as heterodimer) (B), or TraD (0 to 70 nM; as monomer) (C) is shown. The data represent the means of three experiments using two different substrate preparations. Standard deviations were omitted for clarity.