Characterization of garvicin ML, a novel circular bacteriocin produced by Lactococcus garvieae DCC43, isolated from mallard ducks (Anas platyrhynchos).

Lactococcus garvieae DCC43 produces a bacteriocin, garvicin ML (GarML), with a molecular mass of 6,004.2 Da. Data from de novo amino acid sequencing by tandem mass spectrometry and nucleotide sequencing by reverse genetics suggested that the bacteriocin is synthesized as a 63-amino-acid precursor with a 3-amino-acid leader peptide that is removed by cleavage. Subsequently, a covalent linkage between the N and C termini forms the mature version of this novel 60-amino-acid circular bacteriocin.