Part:BBa_K2097000

CpxR binding site attached to a yellow-green color protein (YGCP) acts as a neutral pH indicator.

CpxA-CpxR is a two-component mechanism that is activated at pH 7.4 and repressed at pH 6.0. CpxA is an intermembrane protein that autophosphorylates at a certain external pH, CpxR (a kinase) then gets phosphorylated by CpxA and acts as a transcription factor for the downstream gene, YGCP in this case. This system originally is a transcription factor for the virF gene, but virF was replaced with a reporter. The original sequence was found in Shigella sonnei, but E. coli has a homolog of these proteins so only the appropriate BioBrick prefix/suffix and CpxR binding site were required. Used BBa_K2097002 as the control series.

Usage and Biology

Figure 1.

BBa_K2097000 SequenceAndFeatures ===Design Notes=== The sequence directly from the papers - "Involvement of cpxA, a Sensor of a Two-Component Regulatory System, in the pH-Dependent Regulation of Expression of Shigella sonnei virF Gene" (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC177285/pdf/1775062.pdf) and "Identification of cpxR as a Positive Regulator Essential for Expression of the Shigella sonnei virF Gene" (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC107317/pdf/jb003522.pdf) - was not used. We used the loci detailed in the papers and found the CpxR binding sequence in the GenBank to construct the sequenced used in the experiments. Sequence and Features BBa_K2097000 SequenceAndFeatures ===Functional Parameters=== BBa_K2097000 parameters