Difference between revisions of "Part:BBa K3930026"

Revision as of 22:22, 14 October 2021

3,6-nonadienal induction system and expression in S. elongatus (pCONCOMBRE) Sequence and Features

Introduction

The pCONCOMBRE part (BBa_K3930026) enables the production of 3,6-nonadienal from linolenic and linoleic acids, and is composed by:

- the RA (BBa_K3930027) and LA (BBa_K3930028) integration sites in the NSI locus of the S.elongatus genome (based on the plasmid pAM4951 from Easyclone Marker free kit (Taton et al. 2014))

- the Nb-9-LOX (BBa_K3930030), Cm-9-HPL (BBa_K3930031) and LacI genes (Part:BBa_C0012), for the production of 3,6-nonadienal and LacI repressor. The sequences of the Nb-9-LOX and the Cm-9-HPL were codon optimized for an expression into S.elongatus

- the inducible promoters Trc-theoE-riboswitch (BBa_K3930029) with IPTG and theophylline, driving the expression of Nb-9-LOX and Cm-9-HPL

- the resistance marker SpecR (BBa_K3930032) to select for Cyanobacteria integrants

Construction

IDT performed the DNA synthesis and delivered the part as gBlock. The construct was cloned with an In-Fusion Takara kit into the pAM4951 plasmid and then transformed into E.coli Dh5α strain. Figure 1 shows the restriction map of the resulting clones. The expected restriction profile was obtained for clone A5.

Figure 1: pCONCOMBRE assembly

pCONCOMBRE restriction profile from clone A5 was checked with agarose electrophoresis gel and revealed with EtBr. A theoretical gel is presented on the right of each gel and the NEB 1 kb DNA ladder on the left (note that a different ladder is presented on the theoretical gel)

The plasmid containing the pCONCOMBRE construct was then linearized with the F and R linearization primers pCONCOMBRE. Then the amplicon was integrated into the genome of S.elongatus strain with the traparental conjugation protocol of Gale et al. (2019). Figure 2 shows the electrophoresis gel of PCR on colony to verify clones. The expected sizes were obtained for clone 4, but one amplicon (LA) had not the right size.

Figure 2: Integration of pCONCOMBRE in S.elongatus

pCONCOMBRE integration from clone D2 was checked with agarose electrophoresis gel and revealed with EtBr. A theoretical gel is presented on the right of each gel and the NEB 1 kb DNA ladder on the left (note that a different ladder is presented on the theoretical gel)

pCONCOMBRE insert at NSI was nonetheless successful. The integrant strain was named Synecho-pCONCOMBRE and saved as glycerol stock.

Conclusion and Perspectives

The pCONCOMBRE construction was successfully cloned into the S.elongatus genome. Nonetheless, The characterisation of the production of the 3,6-nonadienal has not been conducted, future iGEM teams may attempt to produce them to verify the functionality of the construct.

References

1. Gale GAR, Osorio AAS, Puzorjov A, Wang B, McCormick AJ. 2019. Genetic Modification of Cyanobacteria by Conjugation Using the CyanoGate Modular Cloning Toolkit. JoVE (Journal of Visualized Experiments).(152):e60451. doi:10.3791/60451.
2. Taton A, Unglaub F, Wright NE, Zeng WY, Paz-Yepes J, Brahamsha B, Palenik B, Peterson TC, Haerizadeh F, Golden SS, et al. 2014. Broad-host-range vector system for synthetic biology and biotechnology in cyanobacteria. Nucleic Acids Res. 42(17):e136. doi:10.1093/nar/gku673.