Part:BBa_K2617017
J23100-RBS-pelB-5D
A combination system of promoter, ribosome binding site and signal peptide for enhancing protein expression(pelB)
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 7
Illegal NheI site found at 30 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal NgoMIV site found at 115
- 1000COMPATIBLE WITH RFC[1000]
Characterization
We have improved the previous part BBa_J23100 by adding RBS and pelB-5D to make it can be used for extracelluar expression. The combination of promoter, RBS and signal peptide makes it convenient to use as a biobrick and gives it the function of extracellular expression.
Vector design for the validation of expression system
For the verification of function, we decided to use the PETase as our reporter protein, which had been used in 2016 iGEM by UESTC-China. Two plasmids were constructed.
| No. | Vector | E.coli resistance | Vector map | Description |
|---|---|---|---|---|
| 1 | Improve-001 | Kan | 0 | BBa_J23100-RBS-pelB+5D-PETase-Ter |
| 2 | Improve-002 | Kan | 2 | BBa_J23100-RBS-PETase-Ter |
Before DNA sequencing, those vectors were verified by restriction enzyme digestion. After electrophoresis analysis, the samples which contained all desired bands were selected and sent for sequencing. The sequencing results showed that all the above constructed vectors were successful.
Validate the extracellular expression of PETase
To validate the extracellular expression of PETase, both supernatant and pellets fractions of LB culture were separated by centrifugation(12000rpm,40℃). The results showed that all supernatant fractions collected from all expression systems exhibited higher PETase activity than controls, while the PETase activity in pellet fractions are comparable with the controls, indicating that the extracellular expression system worked, especially for the piGEM2016-001 which showed the highest activity among all tested samples.
| None |