Difference between revisions of "Part:BBa K4174002:Design"

Revision as of 22:57, 7 October 2022

osmY-sfGFP

Design Notes

This part uses an osmY promoter since this promoter is induced by the cell's entry into stationary phase. In typical E. coli cells, osmY, which helps cells transition into stationary phase when under osmotic or metabolic stress, is not produced during exponential growth phase but is produced during stationary phase. Specifically, the osmY promoter is induced by the rpoS (ribosome polymerase sigma S) at the onset of stationary phase (Chang 2002). Because this promoter is partnered with a sfGFP coding region, this construct fluoresces green once the cell has entered stationary phase.

This composite part is an improvement of the 2006 MIT iGEM team's composite part BBa_J45995, which is a stationary phase detector utilizing osmY. We have replaced GFP with sfGFP from Ceroni et al. 2015, replaced RBS BBa_B0030 with an RBS containing region from Ceroni et al. 2015, removed the scar sequences, and added UNS1 and UNS10 sequences to the ends.

• We elected to use super-folder green fluorescent protein (sfGFP) as opposed to the original GFP, as it folds more readily in Escherichia coli, thus serving as a more effective assay (Pédelacq 2006).
• We switched the original RBS with an RBS containing region used with the sfGFP sequence in Ceroni (2015)'s paper. Our team had previously used those parts together successfully, so we elected to use them together again.
• We added UNS1 and UNS10 sequences to make this part compatible with Gibson Assembly with our backbone, as we also added UNS1 and UNS10 to our pSB1C3 backbone.

Source

Ceroni, F., Algar, R., Stan, G., & Ellis, T. (2015). Quantifying cellular capacity identifies gene expression designs with reduced burden. Nature Methods, 12(5):415-418. Doi: 10.1038/nmeth.3339

References

Chang, D. E., Smalley, D. J., & Conway, T. (2002). Gene expression profiling of Escherichia coli growth transitions: an expanded stringent response model. Molecular microbiology, 45(2), 289-306.

Pédelacq, J. D., Cabantous, S., Tran, T., Terwilliger, T. C., & Waldo, G. S. (2006). Engineering and characterization of a superfolder green fluorescent protein. Nature biotechnology, 24(1), 79-88.