IGEM:IMPERIAL/2006/project/Oscillator/project browser/Prey Construct/Design

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Super Parts Molecular Prey-Predator Oscillator
Actual Part Image:J37015page.JPG
Sub Parts Test Sensing Prey Construct <bbpart>C0261</bbpart> <bbpart>I13401</bbpart>



Design Choices

  • Research into the registry directed us to use AHL as our prey molecule.
  • Design allows for an exponential increase of AHL (to fulfil the Lotka-Volterra model) via a positive feedback loop.
  • The prey part can be decoupled into a prey sensing part and a prey producing part.
  • Initiation of positive feedback loop depends on leaky expression of the tetR promoter which is a constitutive promoter.
    • This leaky expression produces LuxR which can form a dimer with AHL already withing the cell.
    • LuxR, AHL and promoter control the expression of LuxI which produces AHL.
  • Design allows for assesment of status of positive feedback loop via:
    • GFP Production - Linked to LuxI expression
    • AHL Production - Can be indirectly assessed according to J37015 protocol.

INPUTS biological component comments
AHLLuxR & pLuxR To initiate the positive feedback loop, LuxR is produced via leaky expression of the tetR promoter.
OUTPUTS biological component comments
AHLLuxILuxR, AHL and pLuxR form a complex, activating production of LuxI expression which causes enzymatic generation of AHL

Open Issues

  • We need to consider methods of controlling the positive feedback loop while cells are growing to ensure AHL concentration stays at zero. Possible suggestions are:
  • Periodic dilution of culture to allow degradation of LuxI
  • Riboswitch
  • Pops blocker

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