Configurations studied to test the 'position effect' of the LuxR-expression cassette.

Here, the LuxR-repressible promoter BBa_J107100 (green curved arrow), driving the expression of RFP (red box) or GFP (green box), has been assembled in different configurations: in low-copy pSB4C5 (LC) plasmid with the RFP reporter gene A) without the LuxR-expression cassette, B) assembled downstream or C) upstream of the LuxR-expression cassette, and D) co-transformed with the LuxR-expression medium-copy plasmid pLuxR-MC; in medium copy pSB3K3 (MC) plasmid with the GFP reporter gene E) without the LuxR-expression cassette, F) assembled downstream or G) upstream of the LuxR-expression cassette. The BioBrick codes are indicated for each part and a name is provided for each configuration. The '+' symbol in panel D indicates that both plasmids are co-transformed in the cell.