Part:BBa_J153001

Ptrc1O

Ptrc1O, or the trc promoter, is a hybrid of the Escherichia coli trp promoter and the lacUV5 promoter (Brosius etal 1985) [http://www.ncbi.nlm.nih.gov/pubmed/2579077].

It contains the lac O1 operator (proximal to the core promoter) that allows for LacI repression and subsequent induction by IPTG.

Usage and Biology

It was characterized with a GFP reporter construct (Part:BBa_J153003) carried on the broad-host-range shuttle vector pPMQAK1 (Part:BBa_J153000) to be stronger than both the lacZYA operon promoter (Part:BBa_R0010) (ca 35% stronger) and a cI-based TetR-repressible promoter (Part:BBa_R0040) (ca 320 % stronger) in E. coli DH5alpha. Characterization in the cyanobacterium Synechocystis sp. PCC 6803 revealed strong fluorescence from the Ptrc1O-driven construct but no detectable signal from the “Plac” construct and only a weak signal from the “PtetR” construct. Repression of Ptrc1O by LacI in Synechocystis was very modest (Huang etal 2010) [http://www.ncbi.nlm.nih.gov/pubmed/20236988].

The Ptrc2O promoter (Part:BBa_J153002) is of similar strength as Ptrc1O but significantly more repressed by LacI in Synechocystis. However, there are problems inducing this promoter to its full strength, limiting its usability.

When cloning expression constructs driven by Ptrc1O, or just the promoter itself, in a strain not expressing the lac repressor, promoter mutations were frequently observed. Hence it's a good idea to use this promoter in combination with a LacI-expressing E. coli strain.

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]