Part Design

To see all parts we are working on [http://partsregistry.org/cgi/partsdb/pgroup.cgi?pgroup=iGEM2008&group=TUDelft click here]. All parts with number BB_K115050 and higher are the parts involved in color synthesis.

As we need to drain FPP constantly (FPP is toxic to the cell in high concentrations), the idea is to produce a color at all temperatures. We want to express the enzymes of the FPP producing pathway constitutively, independent of temperature. There is a need however to 'tune' this expression to the consumption of the color pathway. In practice this means the eight enzymes necessary for FPP production will be expressed in one operon under the same promotor. However, how strong the promotor and ribosome binding site need to be will have to be determined experimentally. The color enzymes (from FPP to lycopene, B-carotene and zeaxanthianin) will be expressed seperately and under regulation of the RNA temperature sensitive elements. As we will obtain three colors, this would mean two switches, for instance at 27 and 37oC. Lycopene production can be induced constitutively, just like FPP production. This means red colonies will form at all temperatures below 27oC. However the enzyme for B-carotene production would be switched on (by loss of secondary structure of the RNA element) at 27oC and between 27 and 37oC E. coli colonies will be orange. Above 37oC the zeaxanthianin enzyme will be turned on and colonies will have a yellow color.