Regulatory

Part:BBa_K206001

Designed by: Amelia Hardjasa   Group: iGEM09_British_Columbia   (2009-10-17)


Name: pBAD weak
Input: L-arabinose
Output: PoPS

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Usage and Biology

pBAD is an E.coli promoter that is induced by L-arabinose. In the absence of arabinose, the repressor protein AraC (BBa_I13458) binds to the AraI1 operator site of pBAD and the upstream operator site AraO2, blocking transcription [1]. In the presence of arabinose, AraC binds to it and changes its conformation such that it interacts with the AraI1 and AraI2 operator sites, permitting transcription [1].

K206001 is a variant pBAD promoter with a modified AraI1 site that has been shown to be less responsive at low concentrations of arabinose and to exhibit a lower maximum expression than the wild type (BBa_I13453), as measured by coupling to a fluorescent reporter.

What you can do with it:
At a given level of arabinose input, BBa_K206001 will provide a lower level of PoPS output than its family members, allowing analog device responses. See our wiki for a project that makes use of this property.

Compatibility:
Chassis: Best used in the E. coli strain BW27783, which has been modified to permit homogeneous pBAD promoter expression by substituting the chromosomal arabinose-dependent promoter of AraE (arabinose transporter protein) with a constitutive promoter [2].
Backbone: Has been shown to work on plasmid pSB1C3.
Reporter: Has been shown to work with reporters BBa_I13507 and BBa_I763020.


Sequence and Features

Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NheI site found at 125
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 65
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


References

[1] Schlief, R. (2000). Regulation of the L-arabinose operon of Escherichia coli. Trends in Genetics. 16(12):559-565.
[2] Khlebnikov A, Datsenko KA, Skaug T, Wanner BL, and Keasling JD. (2001). Homogeneous expression of the PBAD promoter in Escherichia coli by constitutive expression of the low-affinity high-capacity AraE transporter. Microbiology. 147(12):3241-7.


[edit]
Categories
//chassis/prokaryote/ecoli
//direction/forward
//promoter
//regulation/positive
//rnap/prokaryote/ecoli/sigma70
Parameters
familypBAD promoter
positive_regulators1