Part:BBa_K1899001

Blue Fluorescent Protein mTagBFP generator (Medium RBS)

Improved version of BBa_K592023 by adding a terminator BBa_B1006 3’ to this part.

Usage and Biology

Improvements on BBa_K592023 which is a Blue Fluorescent Protein mTagBFP generator without a terminator. We wondered if the observed fluorescence outputs will be different with versus without a terminator. Therefore, we decided to perform an experiment for comparison. The experimental results showed that the observed fluorescence levels were lowered without a terminator.

Results

We hypothesized that the expression level of mTagBFP is affected by the presence or absence of a terminator. To check if that was true, we compared fluorescence outputs from BFP generators with terminator, versus one without a terminator.

An experimental construct was built where the mTagBFP generator (BBa_K592100) was driven by a constitutive promoter (BBa_J23101) and a medium (BBa_B0032). It was compared against its counterpart which harbored a terminator, BBa_B1006 3’ to the CDS. Constructs without promoters served as controls for auto-fluorescence.

The results showed that the observed blue fluorescence outputs were lowered when the transcription was not properly terminated.

In this experiment, we have improved BBa_K592023 (BBa_B0032-BBa_K592100) by adding a terminator BBa_B1006 3’ to this part in hoping to provide future users with better reporters for their assays. We also would like to raise the awareness on the standards of parts measurement through this investigation. We cautioned on the direct use of previous measurement data for promoters generated using BBa_K592023, and we suggest future iGEM teams that undertake measurement experiments of any kind not to omit parts that might appear irrelevant in the measurement cassettes.

Figure 1. Comparison of the expression levels of a BFP generator with and without a terminator.(a) Circuit diagram illustrates experimental setup of the experiment harboring BBa_B0032. (b) Experimental results of the experiment harboring BBa_B0032. Error bars represent SEM of 3 independent experiments on 3 different days.

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]