Difference between revisions of "Part:BBa K1355001"

Revision as of 04:40, 13 October 2014

Regulation and transport of mercury ions

We call this part an “Essential biobrick”. We designed it meaning to be the key piece of many genetic construction related to mercury, eg. Bio-sensor, bio-remediator, bio-accumulator, and among others. This biobrick has bidirectional promoter, having dual functions: a. in a reverse MerR regulator conjugated with a terminator from the tryptophan operon, and B. a forward MerP and MerT transporters, as represented below:

The operon expression regulation is performed by MerR protein. In the absence of mercury, merR forms a merR-promoter-operator complex, not allowing RNA polymerase recognize the promoter and messengers RNA from other genes involved in operon will be not produced. In the presence of Hg2 + ,MerR protein binds to this element and move out from the promoter-operator complex, which allows the operon genes expression. The MerP is a carrier protein that is located in the periplasmic space and has about 91 amino acids. It binds and transports mercury from the inner membrane to the periplasm, the next mercury transport protein is MerT. The MerT has about 116 amino acids and is also a carrier protein it is located in the inner membrane and when binds to mercury transport it from the inner membrane to the cytoplasm.

Source

This construction is based on sequences present in the pO26-CRL plasmid found in Escherichia coli O26. We added a reverse tryptophan operon terminator to ensure transcription termination of the merR messenger RNA. However we didn’t add transcription terminator after the merP gene, aiming connect this biobrick with others, enabling various functions related to mercury (eg. Bio-sensor, bio-remediator, bio-accumulator)

Figure 1: A) p26-CRL plasmid map; B) Illustration of the tryptophan operon terminator.

Sequence and Features