1.C.37 The Lactococcin 972 (Lactococcin 972) Family

A single sequenced protein comprises the lactococcin 972 family. This protein is plasmid-encoded in Lactococcus lactis. The mature protein is 66 aas long, but it is exported as a 91-residue precursor via the Sec (PSII) protein secretory pathway. It is cleaved extracellularly. It is encoded within a 2 cistron operon that also encodes a 563-residue immunity protein with 7 putative TMSs. Two transcripts are made: one encompasses the whole operon and is synthesized during the exponential growth phase; the other includes only the bacteriocin structural gene and is made both during the exponential and stationary growth phases.

This family belongs to the .



Klaenhammer, T.R. (1993). Genetics of bacteriocins produced by lactic acid and bacteria. FEMS Microbiol. Rev. 12: 39-85.

Martínez, B., M. Fernández, J.E. Suárez, A. Rodríguez (1999). Synthesis of lactococcin 972, a bacteriocin produced by Lactococcus lactis IPLA 972, depends on the expression of a plasmid-encoded bicistronic operon. Microbiology 145: 3155-3161.

Venema, K., G. Venema and J. Kok (1995) Lactococcal bacteriocins: mode of action and immunity. Trends Microbiol. 3: 299-304.


TC#NameOrganismal TypeExample

Class IIc bacteriocin, Lactococcin 972

Gram-positive bacteria

Lactococcin 972 of Lactococcus lactis