FUNCTIONAL ANALYSES OF IMMUNITY PROTEINS FROM BACTERIOCINS PRODUCED BY Enterococcus mundtii

BONACINA JULIETA; SUAREZ NADIA; RAYA RAUL; SESMA FERNANDO; SAAVEDRA LUCILA

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad XLVIII Argentina de Investigación Bioquímica y Biología Molecular; 2012

SAIB

Mundticin CRL1656 (mun CRL1656) and enterocin CRL35 (ent CRL35) are two subclass IIa bacteriocins. The entire biosynthetic cluster of ent CRL35 was previously characterized, and that from mun CRL1656 was identified in the recently sequenced genome. Analysis of both clusters revealed oneORFencoding a putative immunity protein ( ) being part of an operon structure related to the bacteriocin production. In class II bacteriocins that use components of the mannose phosphotransferase system of susceptible cells as targets, immunity proteins form a complex withthe receptor and the bacteriocin and prevent cells from being killed.Another mechanism has been described for some class II bacteriocins, which relies on the activity of a multidrug transporter protein. In this work a functional analysis of both MunC proteinswas performed. Primers were designed to amplify both genes.Expected size fragments were cloned into pNF8 vector downstream GFP gene and under P . The recombinant plasmids were introduced into and 7(Li7). Only recombinant cells of Li7 were recovered. These clones grew in the presence of cell free supernatant (CFS) from CRL35,CRL1656 and synthetic ent CRL35. Li7 plus pNF8 and Li7 were sensitive to all CFS. These results demonstrated that MunC is actively expressed in Listeria cells.