Part:BBa_K1741009
sfGFP under shortened promoter xylA1 with improved 5'UTR
Design
Legend:
XylWT (XylA) [BBa_K1741007]
XylA1 [BBa_K1741008]
XylS [BBa_K1741009]
XylF [BBa_K1741010]
Genes involved in catabolism of xylose in E.coli are organized into two transcription units which are driven by two promoters - XylA and XylF. In order to increase the expression of a protein under control of our XylA1 promoter we added the 5'UTR of the proD promoter[BBa_K1741014] to the XylA of XylWT. In some experiments it seems to be slightly stronger than the original XylA promoter from part BBa_K1741007. The next step was to shorten the promoter by removing its XylF part while keeping the modified 5'UTR (from proD) behind XylA. Finally we tested the reversed XylF part of the XylWT promoter with sfGFP as the reporter gene.
XylS is the strongest xylose-induced promoter. Xylose induced promoter XylA1 is weaker than arabinose and rhamnose promoters.
Results
Legend:
XylWT (XylA) [BBa_K1741007]
XylA1 [BBa_K1741008]
XylS [BBa_K1741009]
XylF [BBa_K1741010]
All our xylose promoters are induced by xylose and repressed by glucose. We also observed slight induction by arabinose. Short version of XylA1 promoter with known functional elements is stronger than two other versions (BBa_K1741007, BBa_K1741008). We observed that XylA1 and XylF had a lower expression than XylWT. XylS is the strongest xylose-induced promoter.
The sfGFP fluorescence [RFU] was measured using Tecan fluorometer.
We also checked the tightness of our promoters.
All of our promoters are induced only by their respective sugars with a small exception of xylose promoters being slightly induced by arabinose and arabinose promoters being slightly induced by xylose. All of our promoters are repressed by glucose.
Contribution
Group: UAM_Poznan 2016
Author: Daria Niewiadomska
The promoter pxylS-M5'UTR (with a lab name: XylS-UTR ), tested in a biobrick pxylS-M5'UTR->sfGFP (BBa_K2014004) is a modified xylose-induced promoter/5’UTR controlling sfGFP protein expression. To make it we exchanged the 5’UTR sequence of xylA-proD5'UTR in a biobrick (BBa_K1741009) to a synthetic, unstructured M5’UTR (picture B) derived from the Mel2 promoter (BBa_K1741004), which we provided to iGEM Registry in 2015.
If you are interested in the pathway of our modifications please click here-> MODIFICATIONS OF XYLOSE INDUCED PROMOTERS
Biobricks used in description:
xylF-xylA - briefly called XylWT (BBa_K1741007)
xylF-xylA-proD5'UTR - briefly called XylA1 (BBa_K1741008)
xylA-proD5'UTR - briefly called XylS (BBa_K1741009)
xylS-M5'UTR - briefly called XylS-UTR (BBa_K2014004)
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 185
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