DIVERCIN V41, A NEW BACTERIOCIN WITH 2 DISULFIDE BONDS PRODUCED BY CARNOBACTERIUM DIVERGENS V41 - PRIMARY STRUCTURE AND GENOMIC ORGANIZATION

Divercin V41 is a new bacteriocin produced by Carnobacterium divergens V41, a lactic acid bacterium isolated from fish viscera. The amino ac id sequence of divercin V41 showed high homologies with pediocin PA-1 and enterocin A. Two disulphide bonds were present in the hydrophilic N-terminal domain and in the highly variable hydrophobic C-terminal do main, respectively. A DNA probe designed from the N-terminal sequence of the purified peptide was used to locate the structural gene of dive rcin V41. A 6 kb chromosomal fragment containing the divercin V41 stru ctural gene (dvnA) was cloned and sequenced. The results indicate that divercin V41 is synthesized as a pre-bacteriocin of 66 amino acids. T he 23-residue N-terminal extension is cleaved off to yield the mature 43-amino-acid divercin V41. In addition, the fragment encodes putative proteins commonly found within bacteriocin operons, including an ATP- dependent transporter, two immunity-like proteins and the two componen ts of a lantibiotic-type signal-transducing system. The genetic organi zation of the fragment suggested important gene rearrangements.