Difference between revisions of "Part:BBa K398326:Design"

Revision as of 14:07, 27 October 2010

Promoter of the CaiF protein

Design Notes

pCaiF is a natural promoter found in E. coli K12, pCaiF is part of the translational unit of the protein CaiF which is a transcriptional regulator of carnitine metabolism under anaerobiosis and glucose limitation. From the original sequence, we took the cAMP-Crp and RNApol sigma 70 binding sites. Under low glucose levels, the cellular cAMP (cyclic Adenosine Mononucleotide Phosphate) levels are high and thus Crp (Catabolite gene activator protein) will bind easier to this molecule forming the complex cAMP-Crp. This complex acts as a transcriptional regulator of over 180 proteins involved in metabolism of secondary carbon sources.

The original purpose of pCaiF for our project was to serve as a promotor for our proteins when glucose or other carbon sources easier to degrade are not in the medium, in that way cells will grow faster and once a certain cell density is reached they can start to degrade other carbon sources like alkanes.

Schematic drawing of the CaiF regulon in E. coli K12 (taken from [http://BioCyc.org/ECOLI/NEW-IMAGE?type=OPERON&object=TU141 EcoCyc]).

This promoter binds to RNA polymerase, sigma 70 (sigma D) factor.

Schematic drawing of the crp binding region in pCaiF.

And the sequence to which crp binds is the following:

Schematic drawing of the crp binding region in pCaiF.

Source

You can find the original sequence and more data about pCaiF in the following [http://BioCyc.org/ECOLI/NEW-IMAGE?type=OPERON&object=TU141 link]

References

1. EcoCyc [http://BioCyc.org/ECOLI/NEW-IMAGE?type=ENZYME&object=CPLX0-226]
2. Eichler K, Buchet A, Lemke R, Kleber HP, Mandrand-Berthelot MA (1996). "Identification and characterization of the caiF gene encoding a potential transcriptional activator of carnitine metabolism in Escherichia coli." J Bacteriol 1996;178(5);1248-57. PMID: 8631699