Stanford/BIOE44:Module3:Day2:mercury

Purpose

To create a novel biosensor that senses inorganic mercury and generates a color as an indicator of the presence of mercury pollution in an aquatic environment.

Rationale

Environmental mercury is usually present as dissolved mercury in water, or as Hg2+ ions.

Long Description

The device is designed to express a color gene as a result of the presence of mercury in water. merR, from Thermus thermophilus HB27, expresses a promoter repressor protein that binds to the promoter region of the mer operon, repressing transcription. In the presence of mercury, the mercury ions bind to the repressor proteins which unbind from the promoter and as a result initiate transcription. In the device, a color generator will be placed downstream of the promoter and merR so that in the presence or mercury, transcription initiates and color is expressed.

Promoter Sequence

gaattcgcggccgcttctagagATGGTGATGAACTCCTGGGCCAGGCCC

AGACCTGCGAGCGTCAAAGCGGCAAGGATCAGCTTCCTCATA CACACCTCCTTGGTGCCGCCGGTAGTATACCCGGCCCTTGCCC TTCTGGCAAGCGCCGCGCGGCCCAGGGAGGGGTTTTTCGCTAGACTAGGGGGTAtactagtagcggccgctgcag Mercury Sensitive Transcriptional Regulator Protein Sequence

gaattcgcggccgcttctagATGCCCTACACCATCGGCGAGCTCGCCC

GGGCGTTTGGCCTTTCTCCTGATGCCCTCCGCTACTACGAAA GGCTTGGGCTCCTCGCCCCCAGCGGCCGTTCGCCCGGGGGGG TTCGCCTCTACGGGGAGGAGGCCTTCCGCCGCCTCCGCTTCA TCAAGGAGGCCCAGGCGGCGGGGCTTAAGCTTGAGGACAT CGCCTGGATCCTCCGCGCCGTGGAGGAGGGCCATCCCCCCT GCCGCCACGTGCGGGAGGCCCTGGCCAAGCGCCTGGCGGA GGTGCGGCGTAGGCTCAGGGAGCTCCAGGCCCTGGAAGCGG CCCTGGCCGAACGGCTGGCCTACGCCGAGGCCCACCCTGACC CTGCTTGCGACGGGCGGGACCGCTGCGTCTATTTGGACC CCCTTGACCCTGGAGCACGCTCCAGGGTCTAGTAAtactagtagcggccgctgcag

References

An initial characterization of the mercury resistance (mer) system of the thermophilic bacterium Thermus thermophilus HB27.

Wang Y, Freedman Z, Lu-Irving P, Kaletsky R, Barkay T.

FEMS Microbiol Ecol. 2009 Jan;67(1):118-29.

Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.