Part:BBa_K427005

MuC sensitivity tuner (PoPS->PoPS)

This is a sensitivity tuner created form the C protein and Pmom promoter of the Mu bacteriophage it can be used to increase the PoPS of a construct. The C protein encoded in the first part of the construct is the activator of the Pmom promoter, which does not begin transcription until the C protein binds to its consensus sequence and attracts the polymerase.

Usage and Biology

The activation of the promoter requires the holenzyme σ70, which normally binds to the -35 and -10 consensus sequences, the promoter has the -10 but does not have the -35 sequences instead it has another sequence approximately at -51 where the activator protein binds. Once the protein is located there, the holenzyme σ70 recognizes the promoter and transcription begins.

This device was designed with two purposes in mind, increase the PoPS output of the pBad promoter (any promoter would work) and change its almost linear production into an almost Boolean one. This part has the following structure: activator protein, transcriptional stop and phage promoter. The sensitivity tuner can be used to achieve both purposes on any construction they just have to be inserted between the desired promoter and the desired coding sequence.
This part has no special safety considerations.

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]

Functional Parameters

It was characterized by using the BBa_K427007 device. Which means that it was characterized by adding a bidirectional terminator BBa_B0014, PBad Weak BBa_K206001 the sensitivity tuner (BBa_K427005) and GFP reporter BBa_E0840.

Figure 1. Transfer function of BBa_K427005. Points represent individual measurements. The line is of a Hill equation fitted to our data.

(d[GFP]/dt)/OD₆₀₀ = C+A*Xⁿ/(Xⁿ+Kⁿ)

Experiment	Characteristic	Value
Transfer Function	Basal rate (C)	1.3 (d[GFP]/dt)/OD600
	Gain (A)	7.87 (d[GFP]/dt)/OD600
	Hill coefficient (n)	15.7
	Switch Point (K)	62.6 [ara] (µM)

References

BBa_F2620 Parts Registry entry with characterisation.