Part:BBa_K4061000
OmpF promoter, controlled by OmpR regulatory protein as part of the Two Component System in E. coli
OmpF promoter is a OmpR regulated promoter that is activated under low medium osmolarity in E. coli especially. This promoter is reciprocally regulated with OmpC promoter (Bba_R0082) depending on the medium osmolarity. OmpF promoter is preferentially expressed in low medium osmolarity. In low osmolarity, the kinase activity of EnvZ (a histidine kinase) is repressed, leading to low concentration of phosphorylated OmpR (OmpR~P). Lower concentration of OmpR~P positively regulates the promoter by binding to high affinity sites (F1, F2, F3). At increased concentration of OmpR~P which occurs at a higher osmolarity, the OmpR~P binds the low affinity F4 site on the promoter which acts a negative regulator and represses the expression of OmpF promoter.
Usage and Biology
This promoter natively regulates the OmpF porin protein which has a relatively large diameter of pore. This is preferentially expressed on E. coli membrane in times when the environment osmolarity is extremely low and the nutrients are scarce. This way, the organism ensures appropriate exchange of ions and nutrients in order to maintain a good osmotic balance when internal osmolarity also starts to drop.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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