Improvement of an Existing Part

In our 30-gRNA array, repeated use of terminators is inevitable. Repeated use of terminators will lead to high repetition and increase in sequence length. It is unacceptable for our gRNA arrays. The team has used polycistron to reduce the use of terminators. When the team browses the part library, we find that BBa_ K2314608，which is a very short terminator in yeast. It's only 68bp in length but has a good performance. On this page，we make the following improvements to this partre.

The following three elements were previously shown to be required for 3'-end formation of mRNA in the Saccharomyces cerevisiae: 3’-end formation of yeast mRNAs involves signals having the following three degenerate elements: (i) the efficiency element, which functions by enhancing the efficiency of positioning elements; (ii) the positioning element, which positions the poly(A) site; and (iii) the actual site of poly-adenylation[1].

The sequences between these sequences can be shortened by us, and reducing the homology of these sequences can reduce the repeatability. The filling of sequences is random, based on the research of Murray MacPherson et al [2].

Figure 1: All synthetic termination subsequences we improved.

In the ultra-long gRNA array, the terminator of each polycistron is mentioned above. The experimental results show that all polycistrons can work normally, which proves the success of the improvement of terminators.