The large antimicrobial proteins (bacteriocins) of streptococci

Bacteriocins are ribosomally synthesised antimicrobial proteins produced by bacteria that generally kill or inhibit species or strains closely related to the producer. Members of the genus Streptococcus produce a myriad of bacteriocins, most of which are small (< 6 kDa) peptides. However, several large (> 10 kDa) streptococcal bacteriocins have also been identified. In this paper, we describe the biochemical and genetic characteristics of the large bacteriocins currently studied in our laboratory, including the identification of stellalysin, a new lytic bacteriocin produced by Streptococcus constellatus subsp. constellatus.