Parts Collection

Overview

The circuit we originally designed was mainly divided into two parts, consisting of a plasmid that converts glucose into the key precursor GPP and a multifunctional plasmid that synthesizes herbicides and EPS under the control of blue light commonly used in the greenhouse.

The first modularized circuit is the blue light inducible system modified from the arabinose operon. As shown in the figure, the Arabinose binding and dimerization domain of native AraC protein was replaced with blue light responsive VVD domain, generating VVD-AraC fusion regulatory protein. Then the modified arabinose operon will regulated by blue light (470nm) instead of arabinose. Three different promoters are selected for the expression of VVD-AraC fusion protein to find the optimal one.

The second modular circuit mainly contains AstABC gene cluster for the synthesis of aspartic acid, under IPTG-inducible Ptrc promoter. It will convert the FPP generated by the precursor plasmid to aspartic acid. The broad-host-vector pBBRMCS1 is used as the backbone. Specific terminators(transcription terminator T1 from the E. coli rrnB gene)and three ribosome binding sites between AA gene clusters were added.

The third modular circuit is for the synthesis of exopolysaccharides (EPS), including the EPS synthesis gene pmgA and galU under the control of Ptrc promoter. This is our improved version of the EPS synthetic plasmid in team XJTU-iGEM in 2020.

We designed a fourth modular circuit for the biosafety and project feasibility. We synthesized the lytic gene and make it under the Pλ promoter to achieve the temperature control of bacterial lysis and product release. When the temperature is 42oC or higher, the regulatory protein of CI will degrade to allow the expression of lysis gene, and our engineered bacteria would break, releasing the product herbicide and EPS.

The number that makes up our parts library is from BBa_K4182000 to BBa_K4182012.

  Name Parts Length(bp)
BBa_K4182000 VVD2m Coding 453
BBa_K4182002 J23101-eSD-VVD-AraC Composite 894
BBa_K4182003 Native Pc-eSD-VVD-AraC Composite 883
BBa_K4182005 FPPs Coding 1537
BBa_K4182006 Circuit of blue light induction regulatory system Composite 6603
BBa_K4182007 Lysis-phi X174 Coding 273
BBa_K4182008 AA cluster Composite 4899
BBa_K4182009 A circuit for efficient exopolysaccharide synthesis Composite 6356
BBa_K4182010 Critical synthesis circuitry from important precursor GPP to AA Composite 10725
BBa_K4182011 Temperature regulated suicide circuit Composite 3733
BBa_K4182012 Ori421 Rep-origin 532

  Address


School of Life Science and Technology, Xi'an Jiaotong University
28 Xianning West Road Xi'an, Shaanxi, China, 710049