Synthetic RBS with Enhancer sequence and 4 bp SD sequence
We made these constructs to measure translation efficiency of our RBSs (SD2: BBa_K1084101, SD4: this part, SD6: BBa_K1084103, SD8: BBa_K1084104). We used TetR repressible promoter (pTet: BBa_R0040), LacZα (BBa_I732006) and double terminator (dT: BBa_B0015).
- pTet-B0034-LacZα-dT negative control
- No insert SD2
- pTet-SD2-LacZα-dT (BBa_K1084121)
- pTet-SD4-LacZα-dT (BBa_K1084122) SD6
- pTet-SD6-LacZα-dT (BBa_K1084123) SD8
- pTet-SD8-LacZα-dT (BBa_K1084124)
We moved our constructs to pSB3K3 plasmid, cultured for 9 hrs in 5 mL LB media round tubes, and performed β-Galactisidase assay. Reaction time was 2 hrs. We did this assay for 24 times.
LacZα protein hydrolyses substrate (Chlorophenol red-β-D-galactopyranoside), which is yellow. Product of this reaction has red color. Therefore, solution will turn deep orange if LacZα expression is strong (fig.1).
We measured absorbance of catalytic reaction solution at 595 nm, standardized using positive control and made into graph (fig.2). Construct with SD4 showed the strongest LacZα activity. Second strongest was the SD8, followed by SD6. SD2 had the weakest activity. There is a significant difference in translation efficiency of our RBSs. Translation efficiency of SD4 and SD8 is the same as BBa_B0034, which is most used RBS.
Sequence and Features
- 10COMPATIBLE WITH RFC
- 12COMPATIBLE WITH RFC
- 21COMPATIBLE WITH RFC
- 23COMPATIBLE WITH RFC
- 25COMPATIBLE WITH RFC
- 1000COMPATIBLE WITH RFC