Composite

Part:BBa_K3187004

Designed by: iGEM TU_Darmstadt 2019   Group: iGEM19_TU_Darmstadt   (2019-10-12)
Revision as of 09:29, 17 October 2019 by Lertu (Talk | contribs)


TEV Cleavage Site x GGGG-Tag for Sortase-mediated Ligation X Superfolder Green Fluorescence Protein

Profile

Name TEV site-polyG-scaffold protein
Base pairs 1028
Molecular weight 27.8 kDa
Origin Tabacco Etch Virus (TEV); Aequorea victoria
Parts T7-Promoter, lac-operator, RBS (g10 leader sequence), TEV protease recognition sequence, polyG, sfGFP, Strep-tag II, T7 terminator
Properties After cleavage by the TEV protease, the polyG tag can be used to fuse sfGFP to the Sortase A recognition sequence(LPTEGG)

Usage and Biology

The TEV protease is cleaving a protein after a specific sequence between Glutamine and Serine or Glycine [1] [2] . We are using this to create a free N-terminal polyG sequence in front of sfGFP so we can use it as substrate in a Sortase A mediated reaction [3] [4] [5] .
sfGFP is a variant of the fluorescence protein GFP that was originally isolated from the jellyfish Aequorea victoria. It has a short maturing time of 13.6 min, has an extinction maximum at 485 nm and an emission maximum at 510 nm. [6] [7]
At the end of the sfGFP a strep tag was added to enable easy protein purification.
The part contains a T7 promoter so it can be transcribed by T7 polymerase, and a lac operator so protein expression can be induced by IPTG.

Methods

Cloning

The fusion protein was cloned into the pACYC2 backbone with Gibson Assembly . To verify the cloning, the sequence was controlled by sanger sequencing by Microsynth Seqlab.

Purification

The protein was heterologously expressed in E. coli BL21 and purified with GE Healthcare ÄKTA FPLC. The used affinity tag was Strep-tag II.

SDS-Page and Western blot

To verify that the CP-LPETGG was produced, a SDS-Page followed by a Western blot was performed.

Results

Cloning and Expression

The successful cloning was proven with sanger sequencing and production with a Western blot.

Figure 1: Western blot of all produced and purified proteins.

Fig. 1 shows that sfGFP with TEV cleavage site has a molecular weight of less than 25 kDa. The expected weight is 27.8 kDa.

Assembly

References

  1. W. Earnshaw, S. Casjens, S. C. Harrison, Assembly of the head of bacteriophage P22: X-ray diffraction from heads, proheads and related structures J. Mol. Biol. 1976, 104, 387. [1]
  2. W. Jiang, Z. Li, Z. Zhang, M. L. Baker, P. E. Prevelige, W. Chiu, Coat protein fold and maturation transition of bacteriophage P22 seen at subnanometer resolutions, Nat. Struct. Biol. 2003, 10, 131. [2]
  3. Dustin P. Patterson, Benjamin Schwarz, Ryan S. Waters, Tomas Gedeon, and Trevor Douglas, Encapsulation of an Enzyme Cascade within the Bacteriophage P22 Virus-Like Particle ,ACS Chemical Biology 2014 9 (2), 359-365 [3]


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 840
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal SapI.rc site found at 138


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