![](https://parts.igem.org/images/partbypart/icon_generator.png)
Part:BBa_K1758102
Translation enhancing 5-UTR + sfGFP under control of T7 promoter
This part is based on BBa_I746909 but contains an optimized untranslated region (UTR, BBa_K1758100), which improves the sfGFP expression in vivo as well as in vitro. This 5'-UTR, which improves the binding of the mRNA to the ribosome ([http://www.ncbi.nlm.nih.gov/pubmed/2676996 Olins et al. 1989]), is especially helpful in in vitro cell free protein synthesis. The 5'-UTR sequence contains a spacer of 10 adenine bases which has been shown to further enhance translation efficiency ([http://www.ncbi.nlm.nih.gov/pubmed/23927491 Takahashi et al. 2013]). The part also contains a double terminator made of B0010 and B0012.
Usage and Biology
This part has been used in E. coli. When T7 polymerase is present, a fast production of sfGFP is observed. This part acts as a reliable reporter protein generator.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000INCOMPATIBLE WITH RFC[1000]Illegal SapI.rc site found at 82
Performance
In our project, we developed cell-free biosensors with the help of in vitro protein synthesis. This part became our positive control due to superior performance compared to I746909
We were sure that a further optimization of sfGFP production was possible. Based on literature screening (for details see background page), we designed a translation enhancing sequence (5'-untranslated region, 5'-UTR, BBa_K1758100) and inserted it into PT7-sfGFP, thereby improving it. The insertion led to the creation of this part.
We designed the 5'-UTR on assumption that if translation was a bottleneck in our cell-free protein synthesis system, this sequence would improve sfGFP production. As verification for the beneficial effect of the 5'-UTR, we performed in vivo experiments, normalizing the fluorescence signal to culture OD600.
Characterization in vivo
![](/wiki/images/0/0e/Bielefeld-CeBiTec_CFPS_UTR.png)
As can be seen in the picture, the difference was observable with the naked eye as well.
Characterization in vitro
![](/wiki/images/5/5c/Bielefeld-CeBiTec_CFPS_UTR_invitro.png)
As can be seen in the figure below, we improved BBa_I746909 (PT7-sfGFP in the figure) by employing of the translation enhancing 5'-UTR (PT7-UTR-sfGFP in the figure) we designed. High yields for in vitro sfGFP production were only observed when 5'-UTR was present.
![CFPS in Tecan plate reader](https://static.igem.org/mediawiki/2015/7/7e/Bielefeld-CeBiTec_150729_CFPS_T7-UTR-sfGFP.png)
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