Difference between revisions of "Part:BBa K2971002"

Latest revision as of 00:08, 22 October 2019

crtB from Deinococcus radiodurans

This part is the gene crtB (dr0862) from the extremophile Deinococcus radiodurans and encodes phytoene synthase (CrtB). Phytoene synthase catalyzes the first reaction in the biosynthetic pathway of carotenoids [1]. The sequence has been codon optimized for expression in Escherichia coli and iGEM registry compatibility.

The UiOslo 2019 team used this gene in a composite part (BBa_K2971004) to produce the red pigment lycopene, in Escherichia coli, by inserting it into a vector along with the genes crtE and crtI. This composite part produced red cells when expressed in Escherichia coli confirming that the part functions as intended.

The part was cloned into an expression vector under the arabionose inducible promotor araC. Successful cloning was confirmed with colony PCR of transformed colonies (figure 1). Colonies that carried the insert was sequenced to check for the potential presence of mutations or frame-shifts.

Figure 1: Colony-PCR of cells transformed with our basic parts (crtE, crtI and crtB)
Primers were designed to amplify the part of the intended plasmid that contains the insert.
Numbers denote the colony checked with the primers. 14 and 23 are PCR products from empty vectors that function as controls. Colony 1-12 and 15 shows that we had several colonies of crtE with the insert. 16-20 shows colonies carrying the crtB insert. 21 show that we had one colony with the insert.

We expressed the protein in E. coli (DH5α)(figure 2). We detected a faint protein band during our SDS analysis; it is likely the expression was not well-optimized.

Figure 2: SDS-page of colonies expressing our basic parts
The expression of our basic parts were tested in E.coli (DH5α). We could detect a faint band of CrtE and CrtI.

References

1. Liu, C., Sun, Z., Shen, S., Lin, L., Li, T., Tian, B., & Hua, Y. (2014). Identification and characterization of the geranylgeranyl diphosphate synthase in Deinococcus radiodurans. Letters in Applied Microbiology, 58(3), 219-224. doi:10.1111/lam.12181 Tian, B., & Hua, Y. (2010). Carotenoid biosynthesis in extremophilic Deinococcus–Thermus bacteria. Trends in Microbiology, 18(11), 512-520. doi:10.1016/j.tim.2010.07.007

Sequence and Features