Part:BBa_K3470011

Methylmercury Transport system - merT (Without MerR)

Circuit

Constitutive Promoter - RBS – MerT - RBS – Double Terminator

Usage and Biology

MerT is a transmembrane protein which receives mercury from MerP, at its first transmembrane helix and transports it into the cytoplasm of the bacterial cell. (T. Barkay et al., 2003). MerE is a transmembrane component of the mer transport system which helps in the uptake of mercury inside the cell. It helps in the transport of organo-mercury compounds.

Proposed Experimentation

To determine the final transport design, three circuits consisting of a combination of genes among MerP, MerC, MerT and MerE have been proposed. The circuit showing the most effective results must be chosen as the bio-brick for the transport system for our first plasmid.

Circuits we test for the final transport design system:

1. MerP - MerT - MerC - MerE

2. MerC - MerE

3. MerP - MerT – MerE

To test the efficiency and characterize each of the 4 parts separately, experiments must be carried out with each of the parts making use of 2 test circuits and 2 controls.

Circuits:

1. The final transport design system

2. Constitutive Promoter- RBS – (The part to be tested, i.e. MerP, MerC, MerT or MerE) -RBS-Double Terminator

Controls:

1. Final circuit design without the part to be tested

2. Wild type Escherichia coli DH5alpha

E. coli cells inoculated with methylmercury chloride must be grown for the required amount of time according to the results of the preliminary experiment respectively for the 2 circuits to be tested and 2 controls. The cell suspension must be centrifuged and the mercury concentration in the supernatant for each set should be determined with gas chromatography. Plots of concentration vs time for each of the sets must analyzed to understand the efficiency of the parts in transporting methylmercury.

Expected result:

The most efficient transport system is the final transport circuit design.

If there are two transport system circuits are of similar efficiency, the one with the least expected genetic burden (smaller length) must be selected. The expected result should show the efficiency of MerP, MerT, MerE, MerC all together in transporting methylmercury, which should be higher than the natural transport (without mer operon transporters).

Sequence and features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 7
  Illegal NheI site found at 30
  Illegal NheI site found at 106
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI site found at 91
  

References

Barkay, T., Miller, S. M., & Summers, A. O. (2003). Bacterial mercury resistance from atoms to ecosystems. FEMS Microbiology Reviews, 27(2–3), 355–384. https://doi.org/10.1016/S0168-6445(03)00046-9

Rossy, E., Sénèque, O., Lascoux, D., Lemaire, D., Crouzy, S., Delangle, P., & Covès, J. (2004). Is the cytoplasmic loop of MerT, the mercuric ion transport protein, involved in mercury transfer to the mercuric reductase? FEBS Letters, 575(1–3), 86–90. https://doi.org/10.1016/j.febslet.2004.08.041