Team:KAIST Korea/Home Intro

From 2012.igem.org

Revision as of 08:28, 26 October 2012 by Mandie (Talk | contribs)

KAIST Korea 2012 iGEM

Home : Introduction

Introduction

"We suggest an auto-regulation module free from induction which utilizes dual-phase switching system."

Throughout past iGEM competitions, many kinds of bio-modules were proposed and tested. They were great and some were brilliant, but it doesn’t seem many of them are universally available. Of course the goal of iGEM is to enrich the database, but we view the beauty of this registry is to contain as many modules which can be readily applied to actual research as possible. Thus, here now, we suggest an auto-regulation module free from induction which utilizes dual-phase switching system and quorum sensing.

We may think of many meanings for this module; bio-computing, in-cell signal processing, and auto-control of cell metabolism. First of all, since we use dual-phase switching system, we may consider each direction of gene expression as a signal; signal 0 or 1 of binary code. Thereby we can use this module to generate in vivo logic gates or computational system.

Dual-phase switching system adopts DNA recombination system of bacteriophage origin. In this system, DNA integrase recognizes specific sequences called attB and attP and then invert the sequence between them. Exisionase revert this sequence into its original state by recognizing the recombination site. We can thereby use this system to turn the pathway on or off.

Products of LuxI and LuxR are used to generate signals in our quorum sensing model. They initiate the operation of auto-regulation module. Lactonase will regulate the signal to yield an oscillating pattern.

As our end product, we selected bio-indigo which comes from indole. This widespread pigment is produced by bFMO, bacterial Flavin-containing MonoOxygenase. Successful production of bio-indigo verifies that our module can be embodied well in metabolic pathway and also proposes its potential usage.


Project Overview

CO2 Fixation Pathway and Pathway Switching Module

1. CO2 Fixation Pathway

Reductive acetyl-CoA pathway is a pathway for carbon dioxide (CO2) fixation in many anaerobes. Acetogenic bacteria, or acetogens, use this pathway to synthesize acetic acid from carbon dioxide. This pathway allows acetogens to grow autotrophically using hydrogen(H2) and carbon monooxide(CO) as electron donor and carbon dioxide (CO2) as electron acceptor.[1]

Because the pathway is non-regenerative, reductive acetyl CoA pathway is a appropriate target pathway to consume atmospheric carbon dioxide (CO2). Nowadays, full genome sequences of bunch of acetogens are available. Also, the enzymes consisting the pathway are elucidated allowing us to reconstruct the pathway in Escherichia coli.

[1] Environ Microbiol. 2008 October ; 10(10): 2550-2573.


2. Pathway Switching Module

Throughout past iGEM competitions, many kinds of bio-modules were proposed and tested. In our project, we are suggesting dual-phase switching module using DNA recombination system that is new to iGEM part registry. With this module we will be able to control metabolic pathway we are targeting.

  • Module Suggestion and Proof of Concept
  • Application of Module

Coupling of suggested module with cell growth and metabolic pathway, we expect our module enable our cells to control their metabolisms according to cell growth.




Hand-made Video



Kaist Footer