Team:Groningen/Promoters draft


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An important question is which promoter we should use to control the chaplin expression. We assume that an ideal promoter would not be active until the biofilm has formed because the expression of hydrophobic proteins might influence the formation of it. Two promoters where found that are active in biofilms but not during normal growth.


The yqxM-sipW-tasA operon is controlled by the yqxM promoter. It is needed for biofilm formation, since tasA is a key protein of the extracellular matrix in such. Since the caplins should work in a similar way to tasA we think the yqxM promoter would be very suitable.


The srfA operon has been reported to be important for the swarming motility, natural competence and sporulation in Bacillus Subtilis. It is controlled by the ComXPA quorum sensing system (JUMP TO PARAGRAPH IN MODELING/EXPRESSION) and hence active in states of high cell densities. Therefore the srfA promoter would be suitable for chaplin expression. Two different lengths of the srfA promoter where chosen due to uncertainties concerning the region between the response element ant the transcription start side of the srfAA protein. In the original promoter this region is unusually long, by shortening it 190bp’s we hope to achieve a higher transcription efficiency. So we came up with two different promoters, the original one and the shortened one.

Quorum sensing and promoter interactions

<img src="Team-Groningen-Pathwaymodel.png">


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