Help:Regulatory
Browse Regulatory parts!
Regulatory parts are those which provide binding regions for RNA polymerase, the enzyme which performs the act of transcription (the conversion of DNA to RNA).
E.coli's RNA polymerase is a large enzyme which spans about 6 turns of a DNA helix, which is equivalent to about 60 base pairs. Thus most promoter regions for e.coli are approximately 60 bp in length.
Some sub-categories of Regulatory parts are:
Constitutive parts
Parts which allow for continual transcription of parts. Often these parts can be de-activated (transcription downregulated) by the addition of ligand. The use of constituitive promoters can be desirable since they are less susceptible to cross-talk and can hypothetically take in PoPS input.
Examples of constitutive parts include
- Part:BBa_R0040 - the pTet promoter region, controlled by tetracycline or its chemical analog [http://openwetware.org/wiki/ATc ATC]
- Part:BBa_R0010 - the pLac promoter region, controlled by the lactose protein or by its chemical analog [http://openwetware.org/wiki/IPTG IPTG]
- Part:BBa_R0051 - the pR bacteriophage lambda promoter region, controlled by the presence of the cI protein
Inducible parts
Parts which are continually "off" (transcription is not induced), but allow for activation (increase transcription) through the addition of particular chemicals
Examples include:
- Part:BBa_R0080 - The araC promoter region, which can be activated by the addition of the sugar [http://openwetware.org/wiki/Arabinose arabinose]
- Part:BBa_I0500 - Another [http://openwetware.org/wiki/Arabinose arabinose] inducible promoter region
References
- Ptashne, Mark. "A Genetic Switch". Cold Spring Harbor Press, 1986.