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Team:KULeuven/Project/Inverter
From 2008.igem.org
Contents |
Invertimer
BioBricks
Components
The input signal for the inverter is filtered by using the T7 RNA polymerase promoter ([http://partsregistry.org/Part:BBa_I712074 BBa_I712074]) and RiboLock3d ([http://partsregistry.org/Part:BBa_J23078 BBa_J23078]). The inverter's output signal is the LuxI protein, encoded by [http://partsregistry.org/Part:BBa_C061 BBa_C0061]. The basis of the inverter system is the LacI repressor molecule, encoded by [http://partsregistry.org/Part:BBa_C0012 BBa_C0012], and the lac promotor ([http://partsregistry.org/Part:BBa_R0011 BBa_R0011]).
Action
When there is a consistent input signal that can penetrate the Filter, LacI is produced from the T7 promoter with the adjacent RiboLock. This LacI ([http://partsregistry.org/Part:BBa_C0012 BBa_C0012]) contains a C-terminal LVA tag for faster degradation and thus better responsiveness. LacI inhibits transcription from the lac promoter just downstream, acting as an inverter for the output LuxI signal. When no (or not enough, because of the filter) signal is present, the LacI repressor will not be made and LuxI will be produced. It is thus clear that when the filter system produces an input signal for the inverter, there will be repression of LuxI production. Otherwise, when no input signal from the filter system is present, LuxI will be produced.
When LuxI is present, it functions as a timer, slowly producing the quorum-sensing molecule [http://partsregistry.org/3OC6HSL 3OC6HSL] from hexanoyl-ACP and SAM. 3OC6HSL has a very long lifetime if no quorum-quenching Lactonase is present and will accumulate. Not only inside the cell but it will also diffuse into the medium.
3OC6HSL is the bridge that links this InverTimer to the next device in our system, CellDeath. Our Reset device also impinges upon this small signaling molecule, making it a true crossroads in our total system.
Input
Output
Filter
InverTimer
Reset
Cell Death
Memory
