Why does pETDuet-1 only have one T7 terminator but two T7 promoters (vector map below)? Is there any advantage of having only one terminator? There are going to be two mRNAs transcribed from this vector: one polycistronic (with two genes) and one monocystronic. Also, presumably, there will be more RNA for the gene expressed from the second promoter compared to the gene expressed from the first. That could lead to higher expression of the second protein, provided that the RBSs are the same. Is there experimental evidence confirming/disproving that hypothesis?
Is there any advantage over using polycistronic mRNA vs moncystronic? Have Duet vectors been used for heterologous expression of long (>40kb) biosynthetic pathways?