Difference between revisions of "Part:BBa K212003"

Latest revision as of 02:43, 22 October 2009

pAgr (S. epidermidis agr operon promoter)

The agr operon transduces the signal that a quorum of S. epidermidis has been reached, based on the extracellular concentration of signalling oligopeptides (see refs 1 and 2). When the bacteria reaches a quorum, the genes under the agr operon are usually turned on (this includes virulence factors that can create a biofilm).

Usage and Biology

Adapted from Ref. 1

The agr operon is essential for quorum sensing in Staphylococcus epidermidis. The agr operon codes for a feedback circuit that is activated by a presence in sufficient concentration of an autoinducing peptide (AIP), which is normally secreted by the bacteria. Only when a sufficient density of bacteria is reached can the threshold AIP concentration be achieved. AIP binds to transmembrane receptor AgrC outside the cell, which in turn phosphorylates AgrA, initiating transcription of the agr promoters. There are two promoters on the agr operon. P2, which transcribes genes agrA, agrB, agrC, and agrD, all of which are needed for the circuit described above. P3 promotes transcription of RNAIII, which drives downstream expression of other quorum phenotypes.

Here, we have both promoters (P2 and P3) biobricked as one part, but any part desired to be under the agr promoter should be on the 3’ end (the P3 promoter, in place of RNAIII).

Sequence and Features