PelB leader sequence
The pelB leader sequence is a sequence of amino acids which, when attached to a protein, directs the protein to the bacterial periplasm, where the sequence is removed by a signal peptidase.[1] Specifically, pelB refers to pectate lyase B of Erwinia carotovora CE. The leader sequence consists of the 22 N-terminal amino acid residues. This leader sequence can be attached to any other protein (on the DNA level) resulting in a transfer of such a fused protein to the periplasmic space of Gram-negative bacteria, such as Escherichia coli, often used in genetic engineering. Protein secretion can increase the stability of cloned gene products. For instance it was shown that the half-life of the recombinant proinsulin is increased 10-fold when the protein is secreted to the periplasmic space. (vijji. Narne, R.S.Ramya)
One of pelB's possible applications is to direct coat protein-antigen fusions to the cell surface for the construction of engineered bacteriophages for the purpose of phage display.
References
- Sockolosky, J. T; Szoka, F. C (2012). "Periplasmic production via the pET expression system of soluble, bioactive human growth hormone". Protein Expression and Purification. 87 (2): 129–135. doi:10.1016/j.pep.2012.11.002. PMC 3537859. PMID 23168094.
- SP Lei et al., Characterization of the Erwinia carotovora pelB gene and its product pectate lyase. J. Bacteriol. 169(9): 4379–4383 (1987).