Part:BBa_K4134011
BpfA (C-terminal 1000bp)
Description
BpfA stands for the biofilm-promoting protein A, a large surface protein. The 1000bp-long fragment of BpfA and the 1000bp-long fragment of AggC, the downstream genes of BpfA, are attached to our vector for homologous recombination so as to fuse the destination fragment (silver-binding protein) to the C-terminus of BpfA. This design enables the destination gene to be displayed on the surface of S. oneidensis. Considering the large size of BpfA, this fusion expression does nearly no harm to the normal physiological state of S. oneidensis and we have approved it through a biofilm growth test and bacterial density measurement.
After all the considerations above, we made the pUC57-BpfA-AtoxⅠ/AgBP2-Kana-loxP-aagC fusion vector. Its core DNA box consists of the coding sequence of a silver binding protein (either Atox1 or AgBP2) and the kanamycin resistance gene (Kana, for recombinant screening). In the following experiment, proliferated vectors were digested into two fragments before electroporation because the linearized expression vector exhibited a high site-specific recombination frequency after being inserted into the S. oneidensis genome. The digestion of the plasmid DNA (20 mg) was carried out with the restriction enzymes KpnⅠ(10 U) and EcoRⅠ(10 U) in a volume of 200 ml.
In short, we displayed a silver-binding protein AtoxⅠ onto the cell surface of S. oneidensis by fusing it to the C-terminus of BpfA, a large surface protein, and used the surface displayed AtoxⅠ as a receptor to capture the silver ions in the matrix of S. oneidensis biofilms.
Sequence and Features| None |