Systems and Synthetic Biology

, Volume 1, Issue 3, pp 119–128 | Cite as

Design and implementation of three incoherent feed-forward motif based biological concentration sensors

  • Robert Entus
  • Brian Aufderheide
  • Herbert M. Sauro
Research Article


Synthetic biology is a useful tool to investigate the dynamics of small biological networks and to assess our capacity to predict their behavior from computational models. In this work we report the construction of three different synthetic networks in Escherichia coli based upon the incoherent feed-forward loop architecture. The steady state behavior of the networks was investigated experimentally and computationally under different mutational regimes in a population based assay. Our data shows that the three incoherent feed-forward networks, using three different macromolecular inhibitory elements, reproduce the behavior predicted from our computational model. We also demonstrate that specific biological motifs can be designed to generate similar behavior using different components. In addition we show how it is possible to tune the behavior of the networks in a predicable manner by applying suitable mutations to the inhibitory elements.


Feed-forward networks Modules Simulation Synthetic biology 



Elongation complex


Feed-forward loop


Green fluorescent protein




Luria broth


Open reading frame


Polymerase chain reaction


Ribosome binding site


T7 RNA polymerase T7-RNAP


S-Adenosyl methionine


Systems biology workbench


Translational efficiency



This work was supported by a grant from the National Science Foundation (Id 0432190). The GFP was kindly donated by Drew Endy form the Biobricks repository. We would also like to acknowledge useful discussions with Vijay Chickarmane.


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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Robert Entus
    • 1
  • Brian Aufderheide
    • 1
  • Herbert M. Sauro
    • 2
  1. 1.Keck Graduate InstituteClaremontUSA
  2. 2.Department of BioengineeringUniversity of WashingtonSeattleUSA

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