Although our project is mainly based on the new part csoR (K4494001), we have also characterized and improved the already-existing part pCusC (K1980004), which is also a copper-sensing part.
We first characterized pCusC to see if it works as expected and to make it a benchmark for our project. The result is successful, as shown in Figure 1.
Next, we conducted random mutation on pCusC, but unfortunately, most of the resulting promoters did not function. We eventually found four different sequences (now K4494099-K4494102). They were then separately characterized (Figure 2).
As could be seen in the results, contrary to what we expected, we did not find any copper-sensitive variants of pCusC. However, K4494102 is a newly found strong promoter, deserving further exploration. Therefore we conclude that we successfully improved the strength of K1980004 while sacrificing its copper-detecting ability.
