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Part:BBa_K1315001 (pqsA)

This is a promoter from Pseudomonas aeruginosa that is positively regulated when the transcription factor PqsR (BBa_K1157001) is activated by PQS (Pseudomonas Quinolone Signal).

Usage and Biology
The Pseudomonas quinolone signal (PQS) is imperative in modulating mechanisms that enable Pseudomonas aeruginosa to survive at times of stress. P. aeruginosa is the main pathogen responsible for severe deterioration in the Cystic Fibrosis lungs. The production of this signal relies on the pqsA operon. The transcriptional factor PqsR (BBa_K1315000) positively regulates this operon.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/25225275
http://www.ncbi.nlm.nih.gov/pubmed/16735731
http://www.ncbi.nlm.nih.gov/pubmed/21539583
http://www.ncbi.nlm.nih.gov/pubmed/?term=pqsr-dependent+and+pqsr-independent+regulation+of+motility+and+biofilm+formation+by+pqs
http://www.ncbi.nlm.nih.gov/pubmed/12393198

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Part:BBa_K1315002 (rpfC)

This is the coding sequence for the RpfC (regulation of pathogenicity factor C) protein. It is the sensor in the two-component signal transduction system of Xanthomonas campestris pv. campestris that activates the regulator RpfG (BBa_K1315003) in the presence of DSF (diffusible signal factor). RpfC eventually leads to the activation of the manA promoter (BBa_K1315006).

Usage and Biology
Quorum sensing and bacterial cell signalling are mechanisms known to be utilised by bacteria to regulate their virulence. The RpfC-RpfG sensory system has been found to activate the production of virulence factors like extracellular enzymes and polysaccharides in Xanthomonas campestris. It has been also suggested that this system is involved in linking environmental stimuli, including DSF, with pathogenicity in Xanthomonas campestris. DSF is a cis-unsaturated fatty acid from the DSF family. The RpfC-RpfG two-component system is the most well understood one and is present in all Xanthomonads.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/?term=r+ryan+dsf+family
http://www.ncbi.nlm.nih.gov/pubmed/?term=A+two-component+system+involving+an+HD-GYP+domain+protein+links+cell%E2%80%93cell+signalling+to+pathogenicity+gene+expression+in+Xanthomonas+campestris

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Part:BBa_K1315003 (rpfG)

This is the coding sequence for the RpfG (regulation of pathogenicity factor G) protein. It is the regulator in the two-component signal transduction system of Xanthomonas campestris pv. campestris that is activated by the sensor kinase RpfC (BBa_K1315002) in the presence of DSF (diffusible signal factor). RpfG eventually leads to the activation of the manA promoter (BBa_K1315006).

Usage and Biology
Quorum sensing and bacterial cell signalling are mechanisms known to be utilised by bacteria to regulate their virulence. The RpfC-RpfG sensory system has been found to activate the production of virulence factors like extracellular enzymes and polysaccharides in Xanthomonas campestris. It has been also suggested that this system is involved in linking environmental stimuli, including DSF, with pathogenicity in Xanthomonas campestris. DSF is a cis-unsaturated fatty acid from the DSF family. The RpfC-RpfG two-component system is the most well understood one and is present in all Xanthomonads.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/?term=r+ryan+dsf+family
http://www.ncbi.nlm.nih.gov/pubmed/?term=A+two-component+system+involving+an+HD-GYP+domain+protein+links+cell%E2%80%93cell+signalling+to+pathogenicity+gene+expression+in+Xanthomonas+campestris

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Part:BBa_K1315005 (clp)

This is the coding sequence for the cAMP receptor-like protein (Clp). This is a transcriptional activator that is normally inhibited by cyclic di-GMP. Inhibition is alleviated by the RpfG regulator (BBa_K1315003) of the RpfC-RpfG two-component system.

Usage and Biology
Quorum sensing and bacterial cell signalling are mechanisms known to be utilised by bacteria to regulate their virulence. The RpfC-RpfG sensory system has been found to activate the production of virulence factors like extracellular enzymes and polysaccharides in Xanthomonas campestris. It has been also suggested that this system is involved in linking environmental stimuli, including DSF, with pathogenicity in Xanthomonas campestris. DSF is a cis-unsaturated fatty acid from the DSF family. The RpfC-RpfG two-component system is the most well understood one and is present in all Xanthomonads. When RpfC (BBa_K1315003) picks up DSF, it eventually signals RpfG (BBa_K1315003) to degrade cyclic di-GMP. This stops the inhibition of Clp and the transcriptional activator can activate genes.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/?term=r+ryan+dsf+family
http://www.ncbi.nlm.nih.gov/pubmed/?term=A+two-component+system+involving+an+HD-GYP+domain+protein+links+cell%E2%80%93cell+signalling+to+pathogenicity+gene+expression+in+Xanthomonas+campestris

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Part:BBa_K1315006 (manA)

This is the manA gene promoter taken from Xanthomonas campestris pv. campestris. It is activated by the transcriptional activator Clp (BBa_K1315005).

Usage and Biology
The DSF-RpfC (BBa_K1315002)-RpfG (BBa_K1315003) sensory system, in all Xanthomonads, activates the production of the manA gene, which codes for endo-mannanase. It has been shown that the transcriptional regulator Clp (BBa_K1315005), when activated binds to the promoter of manA and turns on its synthesis. Clp is usually inactive by cyclic di-GMP molecules that hinder the ability of the transcriptional factor to bind to DNA.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/23285129
http://www.ncbi.nlm.nih.gov/pubmed/20073482

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Part:BBa_K1315007 (BCAM0228)

This is the coding sequence of the BCAM0228 two-component regulator of the BDSF sensory BCAM0227-BCAM0228 system. This system is found in Burkholderia cenocepacia. It is suggested that it activates the cblD promoter (BBa_K1315008).

Usage and Biology
The Burkholderia diffusible signal factor (BDSF/cis-2-dodecenoic acid) is a signalling molecule that regulates virulence in Burkholderia cenocepacia. BDSF belongs to the DSF family which was first described in Xanthomonas campestris. BCAM0227 has been identified as a sensor kinase of the BCAM0227-BCAM0228 system that picks up BDSF. However, the confirmed BDSF signalling pathway only goes as far as BCAM0227. It has been proposed that the next steps involve the BCAM0228 regulator protein. The BCAM0228 regulator though is more similar to the OmpR two-component response regulator rather the RpfG (BBa_K1315003) one. Thus, BCAM0228 is the hypothetical regulator of the BCAM0227-BCAM0228 system.

Recommended reading:
http://www.ncbi.nlm.nih.gov/pubmed/21227698
http://www.ncbi.nlm.nih.gov/pubmed/?term=A+sensor+kinase+recognizing+the+cell-cell+signal+BDSF+(cis-2-dodecenoic+acid)+regulates+virulence+in+Burkholderia+cenocepacia.

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Part:BBa_K1315008 (cblD)

This is a promoter that is activated by the OmpR-like two-component response regulator BCAM0228 (BBa_K1315007) in the BCAM0227-BCAM0228 sensor system. The Burkholderia diffusible signal (BDSF) is picked up by the BCAM0227 sensor kinase that is hypothesised to eventually lead in involvement to the phosphorylation of BCAM0228. BCAM0228 then activates transcription from the cblD promoter.

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Part:BBa_K1315009

PAI-1 Biosensor 1 (GFP readout)
This is a composite part that consists of 4 biobricks. In the front it has P_tet (BBa_R0040) which is constitutively on. This produces LasR all the time with lasR (BBa_C0179) next in the sequence. Only in the presence of the Pseudomonas Autoinducer 1 (PAI-1), LasR forms an complex with PAI-1 and it can then activate the P_lasB (BBa_R0079) promoter that leads to the production of GFP (BBa_E0040).

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Part:BBa_K1315010

PAI-1 Biosensor 2 (GFP readout)
This is a composite part that consists of 4 biobricks. This is an alternative PAI-1 Activated System from BBa_K1315009 that instead uses P_luxR (BBa_R0062). In the front it has P_tet (BBa_R0040) which is constitutively on. This produces LasR all the time with lasR (BBa_C0179) next in the sequence. Only in the presence of the Pseudomonas Autoinducer 1 (PAI-1), LasR forms an complex with PAI-1 and it can then activate the P_luxR (BBa_R0062) promoter that leads to the production of GFP (BBa_E0040).