Part:BBa_K1355004

Mercury ions bioremediating device

To develop a bioremediator, we designed a biobrick device to express MerA protein in mercury’s occurrence. The Mercury ions’ bioremediator device biobrick (BBa_K1355004) is composed by mer bidirectional promoter (BBa_K1355001) attached to the MerA translational unit (BBa_K1355000). It has dual function: A) In reverse: MerR protein regulator transcription; and B) In forward: transcription of MerP - MerT - MerA proteins, as represented below:

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

When MerT, MerP and MerA protein are expressed, the bioremediation will start! MerP and MerT proteins are responsible for transporting mercury from the periplasm to cytoplasm, leading it to mercury ion reductase (MerA)! The beautiful MerA is responsible for reduction from Hg²⁺ in Hg⁰, which is volatile at room temperature and able to passively leave the bacteria.

Figure 1: Mercury Bacter Hg bioremediator (DH5-alpha transformed with BBa_K1355004)

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.

BIONDO, R. Engenharia Genética de Cupriavidus metallidurans CH34 para a Biorremediação de efluentes contendo Metais Pesados. 2008. São Paulo, Brasil.

Nascimento, A. M., & Chartone-Souza, E. (2003). Operon mer: bacterial resistance to mercury and potential for bioremediation of contaminated environments. Genetics and Molecular Research, 2(1), 92-101.

DASH, H. R.; DAS, S. Bioremediation of mercury and the importance of bacterial mer genes. 2012. International Biodeterioration & Biodegradation 75: 207 – 213.

HAMLETT, N. V.; et al. Roles of the Tn21 merT, merP and merC Gene Products in Mercury Resistance and Mercury Binding. 1992. Journal of Bacteriology 174: 6377 – 6385.

PINTO, M. N. Bases Moleculares da resistência ao Mercúrio em bactérias gram-negativas da Amazônia brasileira. 2004. Pará, Brasil.

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
  Illegal NgoMIV site found at 2397
  Illegal NgoMIV site found at 2459
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI site found at 579