Part:BBa_K3185000

SPYtag inserted Tm Encapsulin

Usage and Biology

TmEncapsulin is a protein found from Thermotoga maritima. A paper says that it consists of 60 monomers and forms capsule, Virus-like particle(VLP)[1]. iGEM also treats it as a useful part (BBa_K192000).

We used TmEncapsulin as a biological polymer. We put Spytag inside TmEncapsulin because we used SpyTag/SpyCatcher system to bind it to other parts(SpyCatcher:BBa_K1159200, SpyTag:BBa_K1159201)[2]. Also, this has three tag and cleavage sites. First is 6×His-tag inserted in the C-terminus of TmEncapsulin for protein purification. Second is HA-tag inserted between TmEncapsulin and 6x-His-tag to detect it by using antibodies. Third is a 6x-His tag inserted between the C-terminus of Encapsulin and 6x-His-tag because, in a paper, it is said that 6x-His-tag inserted in the C-terminus of Encapsulin is not presented on the surface of Encapsulin well, so it can’t bind to Ni-NTA Agarose beads. In the same paper, it is also said that heat-resistance is improved when inserting 6x-His-tag and linker between #43 and #44 amino acids of native encapsulin, so we designed it like that[3].

We put it between the BamHI site and the Ndel site on pET11-a. We used BL21 (DE3) for gene expression. We used the Ni-NTA Agarose for purification. After that, we confirmed the molecular weight of SpyCatcher inserted TmEncapusulin by using SDS-PAGE.

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 77
  Illegal BglII site found at 597
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI.rc site found at 426
  Illegal SapI.rc site found at 457
  

Purification

Expression

• Cells were grown in 200ml LB media (100μg/ml Ampicillin) at 37^oC shaking at 140 rpm to an OD600 of 0.5, verifying via a spectrophotometer.

• Protein was expressed in 0.1mM IPTG for 2hours.

SDS-PAGE

<img src=“/Users/momono/Library/Containers/com.apple.Preview/Data/Desktop/スクリーンショット 2019-10-18 23.21.46.png” style=“margin-left: 50%; width:50%; height: auto;">"

References

1 Putri, R.M., Allende-Ballestero, C., Luque, D., Klem, R., Rousou, K.A., Liu, A., Traulsen, C.H.H., Rurup, W.F., Koay, M.S.T., Castón, J.R., et al. (2017).
Structural Characterization of Native and Modified Encapsulins as Nanoplatforms for in Vitro Catalysis and Cellular Uptake.
ACS Nano 11, 12796–12804.

2 Veggiani, G., Nakamura, T., Brenner, M.D., Gayet, R. V., Yan, J., Robinson, C. V., and Howarth, M. (2016).
Programmable polyproteams built using twin peptide superglues.
Proc. Natl. Acad. Sci. U. S. A. 113, 1202–1207.

3 Moon, H., Lee, J., Min, J., and Kang, S. (2014).
Developing genetically engineered encapsulin protein cage nanoparticles as a targeted delivery nanoplatform.
Biomacromolecules 15, 3794–3801.