Difference between revisions of "Promoters/Catalog/Negative"

Revision as of 03:54, 17 May 2009

All the promoters on this page are negatively regulated meaning that increased levels of at least one transcription factor (other than the sigma factor) will decrease the activity of these promoters.

Negatively regulated E. coli promoters

Negatively regulated E. coli σ⁷⁰ promoters

This section lists promoters that are recognized by E. coli σ⁷⁰ RNAP. σ⁷⁰ is the major E. coli sigma factor so there should be RNAP present to transcribe these promoters under most growth conditions (although maximally during exponential growth).

Negatively regulated E. coli σ^S promoters

This section lists promoters that are recognized by E. coli σ^S RNAP. σ^S is the major stationary phase E. coli sigma factor. Use these promoters when you want high promoter activity during stationary phase or during starvation. Since σ^S promoters have the same consensus promoter sequence as σ⁷⁰ promoters, you may find these promoters will be weakly expressed by σ⁷⁰ RNAP.

Negatively regulated E. coli σ³² promoters

This section lists promoters that are recognized by E. coli σ³² RNAP. σ³² is the major heat shock sigma factor in E. coli. Use these promoters when you want high promoter activity during heat shock. These promoters are also active under several different shock responses.

Negatively regulated E. coli σ⁵⁴ promoters

This section lists promoters that are recognized by E. coli σ⁵⁴ RNAP. σ⁵⁴ is a minor E. coli sigma factor that is most highly expressed during nitrogen-limitation. Use these promoters if you want promoter activity to depend on ammonia or nitrogen levels. Alternatively, since this is a minor sigma factor that recognizes promoters with a very different sequence to σ⁷⁰ promoters, this sigma factor could be repurposed to be be expressed and active during some user-chosen set of environmental conditions, essentially producing a user controllable RNAP.