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− | Imagine if you could direct bacterial populations towards a specific location. This ability could have amazing applications, | + | <b>Imagine if you could direct bacterial populations towards a specific location. This ability could have amazing applications, |
− | such as research, bioremediation, substance detection and much more!<br><br> | + | such as research, bioremediation, substance detection and much more!</b><br><br> |
</p> | </p> | ||
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This phenomenon is called <b>chemotaxis</b>.<br><br> | This phenomenon is called <b>chemotaxis</b>.<br><br> | ||
The bacteria sense the environment using receptor proteins (chemoreceptors). | The bacteria sense the environment using receptor proteins (chemoreceptors). | ||
− | These are transmembrane proteins, that contain a periplasmic ligand binding domain (sensing region) and a conservative cytoplasmic domain (signaling region).<br> | + | These are transmembrane proteins, that contain a periplasmic ligand binding domain (sensing region) and a conservative cytoplasmic domain (signaling region).<br><br> |
A detailed explanation on the chemotaxis system can be found <a href="https://2016.igem.org/Team:Technion_Israel/Chemotaxis">here</a>.<br><br> | A detailed explanation on the chemotaxis system can be found <a href="https://2016.igem.org/Team:Technion_Israel/Chemotaxis">here</a>.<br><br> | ||
The variety of chemoreceptors existing in nature is limited, | The variety of chemoreceptors existing in nature is limited, | ||
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<div class="col-md-6 col-sm-12"> | <div class="col-md-6 col-sm-12"> | ||
<a class="pop ocenter"> | <a class="pop ocenter"> | ||
<img src="https://static.igem.org/mediawiki/2016/thumb/e/e5/T--Technion_Israel--S.tar_Fig3_Description2.png/1200px-T--Technion_Israel--S.tar_Fig3_Description2.png" class="img-responsive img-center img-cont" width="800" height="129" style="cursor: pointer;"> | <img src="https://static.igem.org/mediawiki/2016/thumb/e/e5/T--Technion_Israel--S.tar_Fig3_Description2.png/1200px-T--Technion_Israel--S.tar_Fig3_Description2.png" class="img-responsive img-center img-cont" width="800" height="129" style="cursor: pointer;"> | ||
</a> | </a> | ||
− | <p class="text-center"><b>Fig. | + | <p class="text-center"><b>Fig. 3:</b> S.Tar project - Programming the chemoreceptors to respond to new ligands by modifying the ligand binding domain. |
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<br> | <br> | ||
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− | We were successful in generating two new functional chemoreceptors: | + | We were successful in generating two new functional chemoreceptors:<br> |
<b>1. </b> <a href="https://2016.igem.org/Team:Technion_Israel/Proof" >PctA-Tar </a>, a chimera created by replacing the Tar LBD with that of the <i>Pseudomonas</i> receptor PctA.<br> | <b>1. </b> <a href="https://2016.igem.org/Team:Technion_Israel/Proof" >PctA-Tar </a>, a chimera created by replacing the Tar LBD with that of the <i>Pseudomonas</i> receptor PctA.<br> | ||
− | <b>2.</b>< | + | <b>2.</b><a href="https://2016.igem.org/Team:Technion_Israel/Modifications/Rosetta" >Histamine-Tar</a>, a receptor created with the help of computational design - using 'Rosetta' bioinformatics software suite to design mutations in the Tar receptor. |
Using S.Tar, scientists will be able to control the movement of bacteria, and direct them towards or away from a target material. | Using S.Tar, scientists will be able to control the movement of bacteria, and direct them towards or away from a target material. | ||
</p> | </p> |
Revision as of 20:01, 19 October 2016
Introduction
Imagine if you could direct bacterial populations towards a specific location. This ability could have amazing applications,
such as research, bioremediation, substance detection and much more!
Nature provide a tremendous toolbox
Bacteria are able to sense the external environment, and move in response to a chemical stimulus (Fig. 1).
This phenomenon is called chemotaxis.
The bacteria sense the environment using receptor proteins (chemoreceptors).
These are transmembrane proteins, that contain a periplasmic ligand binding domain (sensing region) and a conservative cytoplasmic domain (signaling region).
A detailed explanation on the chemotaxis system can be found here.
The variety of chemoreceptors existing in nature is limited,
and most of them are comprise of relatively the same structure. The main difference being their ligand binding domains.
S.Tar –control of chemotaxis
Project Super Tar - S.Tar in short, is designed to be a novel broadband platform for controlled chemotaxis. Our project focuses on expanding the repertoire of chemoreceptors found in nature.
The base of our project is the E. coli Tar chemoreceptor or more specifically, its ligand binding domain (LBD).
We show that by mutating the native Tar LBD (2) or by interchanging it with that of other receptors (3), the E. coli chemotaxis system can be programmed to respond to completely new ligands.
Fig. 3: S.Tar project - Programming the chemoreceptors to respond to new ligands by modifying the ligand binding domain.
We were successful in generating two new functional chemoreceptors:
1. PctA-Tar , a chimera created by replacing the Tar LBD with that of the Pseudomonas receptor PctA.
2.Histamine-Tar, a receptor created with the help of computational design - using 'Rosetta' bioinformatics software suite to design mutations in the Tar receptor.
Using S.Tar, scientists will be able to control the movement of bacteria, and direct them towards or away from a target material.
FlashLab – A S.Tar detector
As an application of our system, we have designed FlashLab - a user friendly fluidic chip, which utilizes the high sensitivity of the chemotactic response. FlashLab is a simple and low cost platform for the detection of any chemoeffector, using S.Tar bacteria.
Our vision
Project S.Tar aims to give the iGEM community the ability to control bacterial chemotaxis, with the hope that future teams may utilize it and find it useful.
References:
1. Bi, S. and Lai, L., 2015. Bacterial chemoreceptors and chemoeffectors. Cellular and Molecular Life Sciences, 72(4), pp.691-708.
2. Moretti, R., Bender, B.J., Allison, B. and Meiler, J., 2016. Rosetta and the Design of Ligand Binding Sites. Computational Design
of Ligand Binding Proteins, pp.47-62.
3. Reyes‐Darias, J.A., Yang, Y., Sourjik, V. and Krell, T., 2015. Correlation between signal input and output in PctA and PctB amino
acid chemoreceptor of Pseudomonas aeruginosa. Molecular microbiology, 96(3), pp.513-525.