View source for Part:BBa J23100

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<partinfo>BBa_J23100 short</partinfo>
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For video explanation on this promoter family and its use, see [http://www.synbiotrails.org/#!/trail?id=org.clothocad.trails.youtube.TranscriptionModels this].


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===Usage and Biology===

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<span class='h3bb'>Sequence and Features</span>
<partinfo>BBa_J23100 SequenceAndFeatures</partinfo>

===Functional Parameters===
Relative promoter strength estimates (see [http://2009.igem.org/Team:Groningen/Promoters this page] from Groningen 2009):
{|border="1"
!Reference
!Strength
|-
|<partinfo>BBa_J23109</partinfo>
|67
|-
|<partinfo>BBa_J23106</partinfo>
|2
|}
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<partinfo>BBa_J23100 parameters</partinfo>
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==USTC_2009's MEAUREMENT==
[[https://parts.igem.org/Part:BBa_K176011 K176011]]

===Usage and Biology===
The Yale iGEM team has assembled this promoter to citrine (an improved version of YFP, with excitation peak at 514nm and emission peak at 527nm) and a T7-terminator to quantify the level of expression in E. coli and in non-model organism hosts. This construct is available as the biobrick [https://parts.igem.org/Part:BBa_K185000 K185000]

This construct has been successfully cloned into E. coli using the broad-host range vector pKT230, a RSF1010 derived plasmid, as well as using the pPZP200 plasmid which can be transformed into agrobacterium and rhizobium. Leaky expression of citrine was observed. 

==Yale 2015's Characterization==
[[Image:Expression_Level_for_anderson-citrine_(pKT230-Lic).jpg|300px|right]]
[[Image:Expression_Level_for_constitutive_promoters_in_S_meliloti_(pPZP200-LIC).jpg‎|300px|right]]
===Measured strength===
The Yale iGEM team found fluorescence levels nine times above the baseline level in E. coli cells transformed with the promoter-citrine construct. We also found this promoter to be effective in driving gene expression in S. meliloti, with fluorescence levels of over two times that of the baseline observed.

We further compared expression level of this promoter to two of the other promoters in the Anderson collection. The Anderson lab found relatively expression levels of 1, 0.33, and 0.10 respectively when comparing the promoters [https://parts.igem.org/Part:BBa_J23100 J23100 (Anderson Strong)], [https://parts.igem.org/Part:BBa_J23110 J23110 (Anderson Medium)] and [https://parts.igem.org/Part:BBa_J23114 J23114 (Anderson Weak)]. We found the relative expressions to be 1, 1.71 and 1.78 when we transformed our constructs into E.coli: [https://parts.igem.org/Part:BBa_K1856004 K1856004 (Anderson Strong-Citrine)], [https://parts.igem.org/Part:BBa_K1856003 K1856003 (Anderson Medium-Citrine)], [https://parts.igem.org/Part:BBa_K1856002 K1856002 (Anderson Weak-Citrine)]. This highlights that even as all three Anderson promoters are effective in driving gene expression in E. coli, the relative expression level may vary depending on the gene fused to the promoter and on the E. coli strain used. The Yale iGEM team's readings were obtained in E. coli DH10B.

Comparing expression levels in S. meliloti (a rhizobium strain), the relative expression values were 1, 2.36, and no significant expression for the Anderson Strong, Anderson Medium, and Anderson Weak promoters respectively.

<html><hr><h3 style="color:ltblue;"><a href="http://2010.igem.org/Team:Warsaw/Stage1/PromMeas">Team Warsaw 2010's measurement</a></h3></html>
Absolute promoter strength: 13,1pg RNA/minute/ug substrate DNA. It equals 2,80 microPoPS

==Sheffield 2016's Characterisation==


==Nanjing-China 2017's Characterisation==
<p>In order to further extend the range and improve the sensitivity of detection, we expect to enhance the expression of SQR by substituting p<sub>sqrR</sub> with p<sub>cons</sub>, the most efficient promotor among the igem parts. By doing so, we make sure that there is enough SQR in the system to oxidize even a small amount of S<sup>2-</sup> in time.</p>


<p>We have observed RFP response after inducing the modified pathway with 100 μmol/L Na<sub>2</sub>S, which proves that the new pathway works. We are still working on the comparison of two pathways.</p>


==Measured strength==
<html><p>Sheffield 2016 has improved the characterisation of both BBa_J23100 and <a href="https://parts.igem.org/Part:BBa_J23106#Sheffield_2016.27s_Characterisation">BBa_J23106</a>. These parts are a strong and medium promoter respectively, that we have used to design our iron detecting device. We have experimentally validated through fluorimetry that there is indeed a significant difference between expression levels of GFP coupled to the strong and medium promoters. Comparative analysis of promoter strengths can be directly interpreted from the data we obtained. This data can be found both on the original part experience pages of BBa_J23100 and <a href="https://parts.igem.org/Part:BBa_J23106#Sheffield_2016.27s_Characterisation">BBa_J23106</a>, as well as at <a href="2016.igem.org/Team:Sheffield/Parts">our website</a>.

Our team has also improved the function of the BBa_J23100 part, by adding an RBS site downstream of the promoter (BBa_K2016005). BBa_J23100 was originally submitted to the Registry by Berkeley 2006.</p>
<center>
<img style="width:50%" src="https://static.igem.org/mediawiki/2016/5/59/T--Sheffield--RyhB-graph1.png">
</center>
<p>Fluorescence of JC28 mutants or W3110 wild types transformed with RyhB-GFP constructs under the control of medium (MedGFP) or strong promoters (StrGFP).</p><br/></html>