Difference between revisions of "Part:BBa K2273000"
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===Usage and Biology===
 
===Usage and Biology===
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<html><figure><p align="justify">This promoter is controlled by the well-studied regulatory system for competence development in <i>Bacillus subtilis</i> (Figure 1).
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<html><figure style="width:100%><p align="justify">This promoter is controlled by the well-studied regulatory system for competence development in <i>Bacillus subtilis</i> (Figure 1).
 
<i>B. subtilis</i> constantly secretes the ComX pheromone (<a href="https://parts.igem.org/Part:BBa_K2273003">BBa_K2273000</a>), a 9- to 10-amino acid oligopeptide, as a signalling molecule <b>(a)</b>. By rising cell-density, the ComX-concentration in the surrounding medium increases until it reaches a threshold and activates ComP, a membrane-spanning protein kinase <b>(b)</b>. This mechanism is called quorum sensing.
 
<i>B. subtilis</i> constantly secretes the ComX pheromone (<a href="https://parts.igem.org/Part:BBa_K2273003">BBa_K2273000</a>), a 9- to 10-amino acid oligopeptide, as a signalling molecule <b>(a)</b>. By rising cell-density, the ComX-concentration in the surrounding medium increases until it reaches a threshold and activates ComP, a membrane-spanning protein kinase <b>(b)</b>. This mechanism is called quorum sensing.
 
The kinase reacts to the accumulation of ComX by phosphorylating the response regulator ComA <b>(c)</b> which then works as a transcription factor by binding to several promoters and enhancing their activity <b>(d)</b>.</p>
 
The kinase reacts to the accumulation of ComX by phosphorylating the response regulator ComA <b>(c)</b> which then works as a transcription factor by binding to several promoters and enhancing their activity <b>(d)</b>.</p>

Revision as of 19:37, 30 October 2017


PsrfA: a ComA-dependent promoter of Bacillus subtilis

Figure 1: The regulatory system for competence development in Bacillus subtilis. The development of genetic competence is stimulated by quorum sensing due to the secretion of the ComX pheromone and its accumulation in the surrounding medium. (Modified from: Jung et al.)

Usage and Biology

This promoter is controlled by the well-studied regulatory system for competence development in Bacillus subtilis (Figure 1). B. subtilis constantly secretes the ComX pheromone (BBa_K2273000), a 9- to 10-amino acid oligopeptide, as a signalling molecule (a). By rising cell-density, the ComX-concentration in the surrounding medium increases until it reaches a threshold and activates ComP, a membrane-spanning protein kinase (b). This mechanism is called quorum sensing. The kinase reacts to the accumulation of ComX by phosphorylating the response regulator ComA (c) which then works as a transcription factor by binding to several promoters and enhancing their activity (d).

The most important promoter regulated by ComA and involved in competence development is the promoter of the srfA operon (PsrfA). This operon contains not only genes for the production of the antibiotic surfactin (e) but also for ComS (f), another small peptide that prevents the degradation of the autoregulated transcription factor ComK (g). Since the promoter is not only dependent on quorum sensing but also on nutritional conditions, we evaluated the influence of different media (Figure 2). We tested full medium (LB) as well as minimal media (MNGE, MCSE).

Figure 2: Growth (A) and promoter activity of PsrfA (B) in different media. Wild type (WT, pink) and comX-knockout strains (ΔcomX, dark blue) contain a PsrfA luxABCDE fusion.

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]