Part:BBa_K4273006

EEVS

Gene from zebrafish（Danio rerio）involved in biosynthesis of gadusol and gadusolate.

Encoding 2-epi-5-epi-valiolone synthase (EEVS)

That converts sedoheptulose 7-phosphate (S7P)to 2-epi-5-epi-valiolnoe (EEV)

Usage and Biology

EEVS-MTOX are genes from zebrafish, Danio rerio, that support the biosynthesis of gadusol and gadusolate. EEVS and MTOx are expected to facilitate the pathway from SH7 to gadusol to block UV rays and mass produce antidioxants for sunscreen uses. (Osborn et al., 2015). In our experiment, EEVS converts sedoheptulose 7-phosphate (S7P)to 2-epi-5-epi-valiolnoe (EEV). MTOX converts 2-epi-5-epi-valiolnoe (EEV) to gadusol and gadusolate.

Promoters pTDH3 and pPGK1 are selected due to their strong and stable expression in S. Cerevisiae as well as in YPD culture mediums (Apel et. al., 2016). pTDH3 is shown to has the highest stability and strength, followed by pPGK1. Therefore, we used pTDH3 for DDGS and pPGK1 for MTOX for the purpose of gadusol production.

For the production of gadusol

For the production of gadusol, we used promoters pTDH3 to express EEVS and pPGK1 to express MTOX. We also inserted these genes into L2 yeast at position 308 to obtain L4 strain. After testing the absorption spectrum of the supernatant broth after 72 hours of fermentation, a slight absorption peak was observed at around 290 nm. However, we subtracted the curve of the negative control from L4's absorption curve (Figure 15B) in order to better observe the absorption spectrum. As a result, the relative OD curve of L4 strain shows an obvious absorption peak at 290 nm, which suggests the production of gadusol.

Figure 1: Insertion of EEVS-OMT in order to produce MAA-like molecule gadusol. By transforming CRISPR-308 plasmid pCRCT-308, LA, EEVS, MTOx, and RA, EEVS should be inserted at 308 position after assembly in S. cerevisiae (A). We expanded the homogenous arms, and EEVS, MTOX genes through PCR and transformed them into L3. We performed colony PCR on the yeast colonies to determine the existence of LA-EEVS and MTOX (C) and verified this result through the sequencing testing (D), obtaining the L4 strai..

Figure 2: Gadusol production. Fermenting the L4 strain, using the L2 strain as a comparison. After 72 hours of culturing, the absorption curve became clear, and it can be seen that L4 has a peak at 290nm (A). We compared L4’s values to the control, obtaining a clear absorption peak for gadusol.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 521
  Illegal BglII site found at 775
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal AgeI site found at 703
  Illegal AgeI site found at 1309
  
• 1000
  COMPATIBLE WITH RFC[1000]