Difference between revisions of "Part:BBa K1992004"

Revision as of 09:30, 14 October 2016

Tar expression system (promoter+RBS+coding+terminator)

introduction

Tar chemoreceptor is one of four native chemoreceptors of E.coli, it is mediate chemotaxis response towards aspartate and away from Ni and Co (1). This device allows the expression of a functionally native Tar chemoreceptor.

usage and biology

This device constructed from strong promoter (J23100) and RBS (B0034) ensuring high expression of Tar chemoreceptor. High expression of a sole chemoreceptor increase the sensitivity of the bacteria to the substances that interacts with this receptor (מקור). This property makes the system efficient and useful even in low concentrations of desired materials.

expriments and results

In order to test the device it was cloned to chemoreceptor free strain (UU1250) and tested for chemotaxis ability using swarming assay. As can be seen in figure 1 the cells expressing the Tar chemoreceptor create a halo indicating a functional chemotaxis result, which compared to the negative and positive controls. The halo can be seen in a matter of hours ensuring that the halo is a result of a chemotaxis response.

Figure 1

Fig1. (a) Tar expression in UU1250 strain, resulting a halo indicating a functional chemotaxis response. (b) Negative control- UU1250 strain w/o the Tar expression plasmid. (c) positive control - ΔZ strain expressing all chemoreceptors.

The part was successfully sequenced (fig2) ensuring the present of the promoter, RBS, Tar receptor and terminator.

Figure 2

Fig 2. (a) Sequencing chromatogram of the K1992004 BioBrick- the RBS is marked. (b) The alignment of the sequencing results in compared to the designed sequence - alignment was done using snapgene software.

Sequence and Features