Part:BBa_K3185003

SPYCatcher

Usage and Biology

SpyCatcher is a protein that came from the CnaB2 domain of FbaB, Streptococcus pyogenes. In a natural environment, CnaB2 domain is used for attaching to host cells. In a paper, it is partially changed and divided into two domains. (Peptide tag forming a rapid covalent bond to a protein, through engineered bacterial adhesin) Nowadays, these two protein domains are known as SpyCatcher/SpyTag system because they bind irreversibly with a covalent bond.

In our experiment, we used the SpyCatcher/SpyTag system and designed only SpyCatcher part for assay. In addition, this has two tag or cleavage sites. First is 6×His-tag inserted in the N-terminus of SpyC for protein purification. Second is a TEV protease site because, in the paper, it was used for protein purification. (Programmable polyproteins built using twin peptide superglues) However, we didn’t use it in our experiment.

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 by using SDS-PAGE.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

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.