I am part of an undergraduate research group and we are trying to produce a protease in an E.coli gene circuit. We are not sure where to place the His tag in our circuit. The sequence is ...OmpA(gene)->linker->his tag->protease->Terminator->res site Should the His tag be in this position, before the linker, or after the protease? OmpA is a outer membrane protein that will allow a protein to be taken to, and linked to, the outer membrane of the E.coli. Our fear is that the protease will not fold correctly and will be nonfunctional.