Part:BBa_K957008

Arsenic inducible polyHis-MtrB

This part includes the mtrB coding sequence with a poly-His tag appended to the N-terminus.

The purpose of this part is to upregulate mtrB expression in response to arsenic. When expressed in a Shewanella strain lacking mtrB on the chromosome, this composite part will function as a component of a biosensor. Specifically, when such a complemented strain is inoculated in a microbial electrochemical system, current output will increase in response to arsenic.

Within the genetic circuit, arsR acts as a negative autoregulator, repressing not only the expression of downstream mtrB, but also its own expression. Upon association with arsenic salts, ArsR dissociates from the operator of the arsenic inducible promoter, upregulating expression of downstream protein. Because mtrB activity is requisite for functionality of the mtr electron pathway in Shewanella spp., arsenic thus induces electron shuttling through the mtr pathway.

Because of the His tag, this part may also be used for in vitro characterization of mtrB, and will also facilitate the purification of mtrB to obtain its crystal structure.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 255
  Illegal BamHI site found at 491
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]