Team:ETH Zurich/project/background/biotoolssimple

From 2014.igem.org

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(Biological Tools)
(Biological Tools)
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==='''Quorum sensing – Communication using signal molecules'''===
==='''Quorum sensing – Communication using signal molecules'''===
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Bacteria can interact with their surroundings and neighboring cells via cell-to-cell communication. Using this coordination they can coordinate the expression of genes (a gene is the molecular unit of heredity of a living organism) and thus coordinate the overall behavior of the population of bacteria living together.  
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Bacteria can interact with their surroundings and neighboring cells via cell-to-cell communication. Using this communication they can coordinate the expression of genes and thus the overall behavior of the population of bacteria.  
Quorum sensing describes a system including a stimulus and a response. It is the synthesis, secretion and diffusion of small molecules, which are able to trigger a response.  
Quorum sensing describes a system including a stimulus and a response. It is the synthesis, secretion and diffusion of small molecules, which are able to trigger a response.  
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By investigating a specific strain of bacteria already in the early 1980s it was found that depending on the cell density and the concentration of signal molecules, bacteria were able to communicate. The communication was visualized by bioluminescence, which is the production and emission of light by a living organism.
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Already in the early 1980s by investigating a specific strain of bacteria it was found that depending on the cell density and the concentration of signal molecules, bacteria were able to communicate.  
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It was then found that the molecule inducing this bioluminescence is N-(3-oxohexanoyl)-L-homoserine lactone, which is part of the N-acyl homoserine lactone (AHL) family.
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For reasons of simplicity we just call this molecule AHL here.  
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The communication was visualized by bioluminescence, which is the production and emission of light by a living organism.
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It was then found that the molecule inducing this bioluminescence is N-(3-oxohexanoyl)-L-homoserine lactone, which we will for reasons of simplicity just call AHL here.  
Another enzyme named LuxI synthesizes this AHL. The AHL can then diffuse out of a cell and reach other cells. In those other cells it binds and activates a protein called LuxR which regulates the gene transcription (first step on the way from DNA to proteins).
Another enzyme named LuxI synthesizes this AHL. The AHL can then diffuse out of a cell and reach other cells. In those other cells it binds and activates a protein called LuxR which regulates the gene transcription (first step on the way from DNA to proteins).
Further research on such signal molecules was conducted and other systems of AHLs corresponding to the LuxR/LuxI system were found. These additional systems are called LasR/LasI and RhlR/RhlI.
Further research on such signal molecules was conducted and other systems of AHLs corresponding to the LuxR/LuxI system were found. These additional systems are called LasR/LasI and RhlR/RhlI.

Revision as of 13:31, 12 October 2014

Biological Tools

Integrases – Molecules working as scissors on the DNA

Integrases are proteins that work like scissors on two specific sites on the DNA.

Specific sites for the binding of integrases

Within those two sites they can invert the sequence or they can completely remove it. The genes coding for those integrase-scissors and their corresponding specific sites can easily be inserted into bacteria.

This way you can control which genes are expressed by defining integrases present in your system.

In our project integrases working as scissors for DNA is one of the core components we tried to implement in Mosaicoli.

Quorum sensing – Communication using signal molecules

Bacteria can interact with their surroundings and neighboring cells via cell-to-cell communication. Using this communication they can coordinate the expression of genes and thus the overall behavior of the population of bacteria.

Quorum sensing describes a system including a stimulus and a response. It is the synthesis, secretion and diffusion of small molecules, which are able to trigger a response.

Already in the early 1980s by investigating a specific strain of bacteria it was found that depending on the cell density and the concentration of signal molecules, bacteria were able to communicate.
The communication was visualized by bioluminescence, which is the production and emission of light by a living organism. It was then found that the molecule inducing this bioluminescence is N-(3-oxohexanoyl)-L-homoserine lactone, which we will for reasons of simplicity just call AHL here. Another enzyme named LuxI synthesizes this AHL. The AHL can then diffuse out of a cell and reach other cells. In those other cells it binds and activates a protein called LuxR which regulates the gene transcription (first step on the way from DNA to proteins). Further research on such signal molecules was conducted and other systems of AHLs corresponding to the LuxR/LuxI system were found. These additional systems are called LasR/LasI and RhlR/RhlI.