Part:BBa_K3763000

RBS improved on the basis of BBa_B0030

Overview

The ribosome binding site (RBS) is a short sequence upstream the transcription start which is crucial for protein translation.
It has been proveed that its effectiveness is determined by its base-pairing potential to the ribosome and its spacing from the start codon. Therefore, under the condition that the latter remains unchanged, we believe that the function of RBS can be changed by changing its sequence

Characterization

Parts BBa_B0030 is a strong RBS based on Ron Weiss thesis. And its strength is considered relative to BBa_B0031, BBa_B0032, BBa_B0033 and BBa_B0034 by the former iGEM teams.

After consulting a large number of RBS data, we found that most RBS with higher binding efficiency had the repetitive sequence of "aggg", or "aaa" after the start codon. B0030 was the one with the highest expression efficiency among the four existing RBS, with the sequence of "aaa" but no sequence of "aggg". Therefore, we modified the sequence to change "aagagg" to "aggagg", so that it could simultaneously have the characteristics of two sequences with high binding efficiency. In later experiments, we wanted to compare the performance of the two sequences.

Figure 1. The change in sequence.

Figure 2. Plasmid design.

We further combine the two RBS with the promoter pFadD_Lac which is sensitive to fatty-acids. After the successful transformation of the plasmid, we used different concentrations of fatty acids for induction for different times. The expression level of eGFP was determined by fluorescence detection with a microplate reader, reflecting the performance of the RBS. The results are as follows:

Figure 2. Plasmid design.

Figure 2. Plasmid design.

Sequence and Features No part name specified with partinfo tag.