CHALON Miriam Carolina
Co-expression and characterization of enterocin CRL35 and its mutant in Escherichia coli Rosetta
MASIAS, ER; PICARIELLO, G; ACUÑA, L; CHALON M.C.; SESMA, F; MORERO, R.D; SAAVEDRA, L; MINAHK CJ
DE GRUYTER OPEN
Año: 2014 vol. 1 p. 30 - 42
Abstract: Even though many sequences and structuresof bacteriocins from lactic acid bacteria have beenfully characterized so far, little information is currentlyavailable about bacteriocins heterologously producedby Escherichia coli. For this purpose, the structural geneof enterocin CRL35, munA, was PCR-amplified usingspecific primers and cloned downstream of PelB sequencein the pET22b (+) expression vector. E. coli Rosetta(DE3) pLysS was chosen as the host for production andenterocin was purified by an easy two-step protocol. Thebacteriocin was correctly expressed with the expectedintramolecular disulfide bond. Nevertheless, it wasfound that a variant of the enterocin, differing by 12 Dafrom the native polypeptide, was co-expressed by E.coli Rosetta in comparable amount. Indeed, the mutantbacteriocin contained two amino acid substitutions thatwere characterized by matrix assisted laser desorptionionization-time of flight (MALDI-TOF) and HPLCelectrospray(ESI)-Q-TOF tandem mass spectrometry (MS/MS) sequencing. This is the first report regarding theproduction of mutants of pediocin-like bacteriocins in theE. coli expression system.