Part:BBa_K2093000
Porine-pIVleaky-Marciano
The BioBrick encodes a mutated version of the pIV porin from the filamentous bacteriophage f1. Those secretins are quite interesting since their opening are controlled by phages (1). When expressed in E. coli, this porin is localized in the outer membrane. The mutation confers a "leaky" phenotype to the bacteria, i.e. periplasmic content is released in the culture supernatant (2). Spagnuolo and his team used a random mutation technique, followed by a positive selection to get those leaky mutants. Indeed mutants having trouble to stay entirely closed or opened (leaky), were obtained after mutations in the C-terminal secretin family domain; GATE 1 and GATE 2 and in the N-terminal (periplasmic portion) which could be involved in the controlled opening of the gate.
This property is potentially useful for secreting recombinant proteins or metabolites. When expressed in E. coli strains lacking the endogenous lamB outer membrane protein, pIVm allows the bacteria to grow on oligomaltosides (tetra-, penta-, hexa- and hepta-maltose) as carbon source.
1. Marciano, Denise K., Marjorie Russel, et Sanford M. Simon. 1999. « An Aqueous Channel for Filamentous Phage Export ». Science 284 (5419): 1516‑19. doi:10.1126/science.284.5419.1516.
2. Spagnuolo, J., Opalka, N., Wen, W. X., Gagic, D., Chabaud, E., Bellini, P., Rakonjac, J. (2010). Identification of the gate regions in the primary structure of the secretin pIV. Molecular Microbiology, 76(1), 133–150. doi:10.1111/j.1365-2958.2010.07085.x
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
| None |