Difference between revisions of "Part:BBa K1065311"

Revision as of 22:43, 4 October 2013

Blue-light photoinducible AmilCP + EFE producing device

This device is composed by the blue light sensor device, an inverter cassette, the reporter amilCP and EFE (Ethylene Forming Enzyme) coding sequence. This device allows to produce amilCP (a blue chromoprotein) and 2-Oxoglutarate Oxygenase/Decarboxylase enzyme when culture is exposed to blue light. To allow this behavior an inverter cassette was included into the device. The cassette is composed by the cI coding sequence and the repressible promoter pLambda. Everything is under the control of promoter J23100.

This part was successfully cloned by UNITN-Trento 2013 iGEM team in order to design an ethylene producing device that is induced by blue light to speed up fruit ripening.

Parts from 2011 Uppsala-Sweden team and 2006 Berkeley team were used along with our new ethylene producing part BBa_K1065000.

SAFETY NOTES: this part is an ethylene producing system: ethylene is explosive at high concentration, we suggest to handle this parte carefully. Cell cultures should be opened under a chemical hood.

Usage and Biology

YF1, the blue light sensor, is a fusion protein of the LOV blue light sensor domain of Bacillus subtilis (YtvA) and FixL histidine kinase domain (from Bradyrhizobium japonicum). [1] [2]
In the dark, the autophosphorylated YF1 phosphorylates FixJ, its Response Regulator, which activates the pFixK2 promoter allowing the expression of the inverter cI. cI inhibits pLambda activity thus amilCP and EFE transcription.
Under constant illumination with blue light net kinase activity is strongly suppressed, consisting in a consequent inactivation of pFixK2: the outcome is AmilCP+EFE production.
EFE enzyme was thoroughly studied by many reasearch groups. It was purified and characterized with an in vitro test [3].It was then transformed and ectopically expressed in E.coli [4] and in Synecocystis sp [5].

We characterized this part in E. coli using cells NEB10beta and have some preliminary results. We are in the process of acquiring gas-chromatocgraohic measurements in order to test light dependent EFE production. Up to now, we were only able to observe amilCP production upon blue light illumination: since the blue reporter correctly appeared only in the induced control, we think that ethylene could be properly produced.

Sequence and Features

References

1. Moglich A, Ayers RA and Moffat K. (2009) Design and Signaling Mechanism of Light-Regulated Histidine Kinases. J. Mol. Bio. 385, 5, 1433-1444.
2. Ohlendorf, R., Vidavski, R.R., Eldar, A., Moffat, K. & Möglich, A.(2012). From Dusk till Dawn: One-Plasmid Systems for Light-Regulated Gene Expression. J. Mol. Biol., 416: 534: 542
3. Nagahama K, Ogawa T, Fujii T, Tazaki M, Tanase S, et al. (1991) Purification and properties of an ethylene-forming enzyme from Pseudomonas syringae pv. phaseolicola PK2. Journal of General Microbiology 137: 2281–2286.
4. Fukuda H, Ogawa T, Ishihara K, Fujii T, Nagahama K, et al. (1992) Molecular cloning in Escherichia coli, expression, and nucleotide sequence of the gene for the ethylene-forming enzyme of Pseudomonas syringae pv. phaseolicola PK2. Biochem Biophys Res Commun 188: 826–832.
5. Guerrero F, Carbonell. V., Cossu M, Correddu D, Jones PR (2012) Ethylene Synthesis and Regulated Expression of Recombinant Protein in Synechocystis sp. PCC 6803. PLoS ONE 7(11): e50470.
6. Octamerization of CI repressor is needed for effective repression of PRM and efficient switching from lysogeny. Ian B. Dodd,1 Alison J. Perkins, Daniel Tsemitsidis, and J. Barry Egan , Genes and Development (Vol 15, No. 22) 3013-3022: 2001