Difference between revisions of "Part:BBa R0073"

Latest revision as of 03:15, 2 November 2017

Promoter (Mnt regulated)

Expression Level of the Mnt- and PenI-Regulated Promoters

(Characterized by SDU-Denmark)
The PenI-regulated promoter exhibits a stronger expression than the Mnt-regulated promoter.
Applicability of two different promoters was studied for the expression of genes in E. coli. These were the PenI-regulated, BBa_R0074, and the Mnt-regulated promoters, BBa_R0073, whose repressors are not found in E. coli, making the gene expression constitutive in this organism. The relative expression and noise levels were assessed using fluorescence microscopy of YFP reporter systems, BBa_I6103 and BBa_I6104, expressed on pSB1C3 in MG1655 at OD₆₀₀=0.3-0.5. For this purpose an Olympus IX83 with a photometrics prime camera was used with exposure time for YFP at 200 ms.

Figure 1. Fluorescence microscopy of YFP under the control of PenI-regulated and Mnt-regulated promoters on pSB1C3 in E. coli MG1655 at OD₆₀₀=0.3-0.5.

From the data obtained, it was evident that the PenI-regulated promoter mediated a substantially higher level of YFP expression than the Mnt-regulated promoter, as seen in Figure 1. Furthermore, the PenI-regulated promoter displayed a notably lower level of noise.

Usage and Biology

Sequence taken from Figure 1 (N15 sequence) of Stormo et al. JMB 229:821 (1993) (PMID:8445649). G was used (to create wild-type operator).

Sequence and Features