Part:BBa_K4432000

T5 promoter

This part is a LacI regulated hybrid promoter derived from the P_N25 promoter of the bacteriophage T5 [1–3].

Usage and Biology

P_N25 is an early phase strong promoter of the bacteriophage T5 which is recognized by the E. coli RNA polymerase [1], contrary to the well known T7 promoter which requires its own specific bacteriophage T7 RNA polymerase.

This hybrid promoter (Figure 1) was created to achieve high protein expression in any E. coli strain [2,3]. It contains 2 LacI binding sites, one of which is embedded between the -35 and the -10 boxes, while the other is part of the downstream transcribed region.

Figure 1. Sequence comparaison between the P_N25 and P_T5 promoters.

As for all other LacI controlled promoters, this promoter is repressed in E. coli strains overexpressing the LacI transcriptional regulator and is inducible by IPTG.

References

[1] Gentz R, Bujard H. Promoters recognized by Escherichia coli RNA polymerase selected by function: highly efficient promoters from bacteriophage T5. Journal of Bacteriology (1985) 164: 70–77.

[2] Bujard H, Gentz R, Lanzer M, Stueber D, Mueller M, Ibrahimi I, Haeuptle M-T, Dobberstein B. A T5 promoter-based transcription-translation system for the analysis of proteins in Vitro and in Vivo. Methods in Enzymology. Vol155. Academic Press (1987) 416–433.

[3] Hu MC. Efficient protein expression system. US7528245B2 (2009).

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]