Part:BBa_K1766005
This part consists of the quorum synthase RhlI under control of an OmpR dependent promoter. The promoter is activated by phosphorylated OmpR protein. RhlI produces N-butyryl-homoserine lactone (BHL), a quorum sensing molecule which enables cell to cell signaling.
Biology
The OmpR dependent promoter comes from Escherichia coli and has three bind sites for phosphorylated OmpR. Endogenously it is involved in osmoregulation, as it regulates expression of outer membrane porin C (OmpC).
The OmpR protein is phosphorylated or dephosphorylated by the osmoreceptor EnvZ, which exhibits both kinase and phosphatase activity. At low osmolarity OmpR is dephosphorylated and expression of OmpC is low. At high osmolarity OmpR is phosphorylated by EnvZ, which increases OmpC expression.
In this construct OmpC has been replaced by RhlI. RhlI is a quorum synthase from Pseudomonas aeruginosa. Endogenous RhlI is involved in biofilm formation, motility and virulence. However, quorum sensing can be used to induce and coordinate diverse behaviors in neighbouring cells.
Experiments
This part was created to convert the intracellular signal from the chimeric EnvZ-Affibody receptors, created by iGEM Stockholm 2015, into an extracellular signal that could be detected by a read-out strain.
To show that expression of OmpR-Regulated-RhlI is controlled by OmpR we performed an osmolarity bioassay. We used Chromobacterium violaceum in soft agar as a BHL reporter. In the presence of BHL the C. violaceum lab strain CV026 produces a violet pigment called violecin.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BglII site found at 787
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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