9.B.86 The Propionicin (Propionicin) Family

Propionicin F, is a bacteriocin isolated from Propionibacterium freudenreichii. The bacteriocin has a bactericidal activity and is only active against strains of P. freudenreichii. Propionicin F appears to be formed through a processing pathway new to bacteriocins. Propionicin F corresponds to a 43-amino-acid peptide in the central part of a 255-amino-acid open reading frame, suggesting that mature propionicin F is excised from the probacteriocin by N- and C-terminal proteolytic modifications. The gene for the precursor, pcfA is cotranscribed with genes encoding a putative proline peptidase and a protein from the radical S-adenosylmethionine family. A gene encoding an ABC transporter is in close proximity to the bacteriocin structural gene. The mechanism of action of Propionicin F is not known (Brede et al., 2007). May contain a glycosyl transferase domain (PLN02939).  May also be related to SdpC homologues (TC# 9.B.139.3.1).