Part:BBa_K1355003

Mercury ions accumulator device

We designed a biobrick device to bind and inactivate Hg. It is composed by two parts: Essential biobrick (BBa_K1355001) attached to the MBP biobrick (BBa_K346004) that was synthesized by iGEM Peking 2010. As described by the team, this MBP design was based on the tandem of two metal binding domains to make a high performance and less energy consuming metal binding peptide. The idea came from the high similarity of the C-terminal metal binding domain with MerR family TFs, which indicates a similar metal recognition mechanism and metal-protein complex structure. The Mercury ions accumulator device biobrick (BBa_K1355003) has dual function: A) In reverse: transcription of MerR regulator protein; and B) In forward: transcription of MerP - MerT - Metal Binding Peptide proteins, as represented below:

In absence of mercury, MerR forms a MerR-promoter-operator complex, preventing RNA polymerase to recognize the promoter, consequently, messengers RNA for MerPT and MBP will not be transcript. In presence of Hg2+, MerR protein binds to this element and dissociates from the promoter-operator complex, allowing MerPT and MBP expression, as represented below:

When MerT, MerP and Metal Binding Protein (MBP) proteins are synthesized, the bioaccumulation will start! MerP and MerT protein are responsible for mercury’s transport of mercury from the periplasm to cytoplasm, leading it to MBP! The MBP binds to the mercury in the cytoplasm, inactivating it.

Mercury Bacter Hg bioaccumulator (DH5-alpha transformed with BBa_K1355003)

References

Gupta, R. K., Dobritsa, S. V., Stiles, C. A., Essington, M. E., Liu, Z., Chen, C. H., ... & Mullin, B. C. (2002). Metallohistins: A new class of plant metal-binding proteins. Journal of protein chemistry, 21(8), 529-536.

Mejáre, M., & Bülow, L. (2001). Metal-binding proteins and peptides in bioremediation and phytoremediation of heavy metals. TRENDS in Biotechnology, 19(2), 67-73.

Deng, X., & Wilson, D. (2001). Bioaccumulation of mercury from wastewater by genetically engineered Escherichia coli. Applied microbiology and biotechnology, 56(1-2), 276-279.

Licini, G., & Scrimin, P. (2003). Metal‐Ion‐Binding Peptides: From Catalysis to Protein Tagging. Angewandte Chemie International Edition, 42(38), 4572-4575.

Sequence and Features

Assembly Compatibility:

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

  Illegal NheI site found at 988
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 586
  Illegal NgoMIV site found at 1160
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI site found at 579