Part:BBa_K4767001

Pars

This part is an arsenic-responsive promoter that couples with the transcriptional regulator ArsR. It is from Escherichia coli genome which can response to the ArsR protein and block the transcription of downstream genes.

Usage and Biology

This operon was found in E. coli, which contains arsR (transcriptional regulator), arsB (arsenate permease), and arsC (arsenate reductase). When arsenic is absent, the transcription regulator ArsR binds to the ArsR-binding site (ABS) within the ars promoter and blocks transcription. Once arsenic is present, it binds to ArsR and changes the local structure of the promoter to activate the transcription of the ars genes and clear arsenic in the cell.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Functional Parameters

In 2023, CUG-China used this arsenic-responsive transcription system to detect arsenic. We placed gfp at downstream of the P_ars -arsR system and demonstrated the As(Ⅲ) can bind the ArsR and drive the expression of gfp. As the figure shows, with an increase in arsenic concentrations, the fluorescence intensity increased in response.

Figure 1. The fluorescence curves of Shewanella oneidensis MR1 cells with the arsenic-responsive transcription gene circuits.

References

Jia X, Bu R, Zhao T, et al. Sensitive and specific whole-cell biosensor for arsenic detection[J]. Applied and Environmental Microbiology, 2019, 85(11): e00694-19.