Part:BBa_R0084

Promoter (OmpR, positive)

Positively regulated, OmpR-controlled promoter. This promoter is taken from the upstream region of ompF. Phosphorylated OmpR binds to the three operator sites and activates transcription.

Usage and Biology

In nature, this promoter is upstream of the ompF porin gene and is both activating and repressing. The regulation of ompF is determined by the EnvZ-OmpR osmosensing machinery. EnvZ phosphorylates OmpR to OmpR-P. At low osmolarity, EnvZ has a low activity, producing a small concentration of OmpR-P. This OmpR-P binds to high-affinity sites on ompF, activating transcription. At high osmolarity, however, EnvZ is more active, creating a high OmpR-P concentration. OmpR-P then binds to the low-affinity sites on ompF, repressing transcription. See Notes section for further discussion of negative regulation.

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: Austin_UTexas

BBa_R0084 parameters

Burden Imposed by this Part:

Burden Value: -1.7 ± 7.7%

Burden is the percent reduction in the growth rate of E. coli cells transformed with a plasmid containing this BioBrick (± values are 95% confidence limits). This BioBrick did not exhibit a burden that was significantly greater than zero (i.e., it appears to have little to no impact on growth). Therefore, users can depend on this part to remain stable for many bacterial cell divisions and in large culture volumes. Refer to any one of the BBa_K3174002 - BBa_K3174007 pages for more information on the methods, an explanation of the sources of burden, and other conclusions from a large-scale measurement project conducted by the 2019 Austin_UTexas team.

This functional parameter was added by the 2020 Austin_UTexas team.