Part:BBa_K1489002

Lpp-OmpA-Linker (pSB1C3)

Outer membrane protein A (OmpA) is a common outer membrane protein found in bacteria that serves various purposes. For our purposes, the beta-barrel transmembrane domain can be utilized to anchor otherwise soluble proteins in the outer cell membrane. Lpp serves to direct the fusion protein, while an unstructured linker (GGGSGGGS) serves to separate OmpA from its cargo in order to avoid interactions between the two proteins.

The expressed protein is structurally identical to BBa_K103006. This version of the biobrick has been moved into the new backbone, pSB1C3, which contains the gene for chloramphenicol resistance. This resistance gene contains an internal SacI site, making the SacI site at the end of the gene almost unusable for RE cloning. BBa_K1489003 mutagenizes this SacI site into a KasI in order to avoid this issue.

Function improvement

This part has been improved in 2018 by Team SJTU-Biox-Shanghai. The improvement focused on better function in cancer targeting. To see more details about the construction and result, click the hyperlink below:

BBa_K2552005

We added a 15-AA oligo peptide to the C-terminal of OmpA to give it the ability to target cancer. The oligo peptide has the ability to bind to Thomsen–Friedenreich antigen (T antigen) that exist on some kinds of cancer cells(like colorectal cancer) by a mechanism similar to antigen-antibody binding reaction. The SWIIS-MODELING result of the structure is shown below.

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]