Difference between revisions of "Part:BBa K346002"

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PmerT promoter (mercury-responsive)

PmerT is a promoter from Tn21 mercury resistance (mer) operon. The mer operon of Tn21 consists of two tightly overlapped, divergently oriented promoters – PR and PTPCAD.(Park, Wireman et al. 1992). PR is the promoter of the regulatory protein gene, merR, and PTPCAD is for the transcription of the structural gene – merPTCAD. They are called merOP as a whole. MerR, as a regulatory protein, always binds to merOP as a homodimer and enhances the occupancy of PTPCAD by RNA polymerase regardless of the presence of Hg(II), although only after Hg(II)’s binding can the dimer stop preventing the formation of the open complex by RNA polymerase. Also, MerR repress its own expression independently of Hg(II). In our design, merR was isolated from the operon and assembled with constitutive promoters of certain strength to maintain its expression intensity at certain level. For the same reason, the divergent promoter PR was also removed by deletion of its -35 region

Sequence and Features