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.
References:
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.
Examples:
TC#	Name	Organismal Type	Example
1.C.37.1.1	Class IIc bacteriocin, Lactococcin 972 of 91 aas and 1 TM	Gram-positive bacteria	Lactococcin 972 of Lactococcus lactis

1.C.37.1.10	Lactococcin 972 family bacteriocin of 220 aas and 1 TM		Bacteriocin of Thermoactinospora rubra

1.C.37.1.11	Lactococcin 972 family bacteriocin of 179 aas and 2 TMSs.		Bacteriocin of Mycetocola lacteus

1.C.37.1.12	Uncharacterized protein of 133 aas and 1 TMS		UP of Melghirimyces algeriensis

1.C.37.1.13	Bacteriocin of 98 aas and 1 TMS		Bacteriocin of Chlamydia trachomatis

1.C.37.1.2	Lactococcin 972 family bacteriocin of 127 aa		Lactococcin of Mogibacterium diversum

1.C.37.1.3	Uncharacterized protein of 131 aas and 1 N-terminal TMS		UP of Dorea formicigenerans

1.C.37.1.4	Lactococcin 972 family bacteriocin of 131 aas and 1 TM		Bacteriocin of Listeria monocytogenes

1.C.37.1.5	Lactococcin 972 family bacteriocin of 99 aas and 1 TM		Bacteriocin of Clostridium cuniculi

1.C.37.1.6	Lactococcin 972 family bacteriocin of 129 aas and 1 TM		Bacteriocin of Agreia sp.

1.C.37.1.7	Uncharacterized protein of 148 aas and 1 TMS		UP of Anaerostipes hadrus

1.C.37.1.8	Bacteriocin of 129 aas and 1 TMS		*Bacteriocin of Erwinia* sp.**

1.C.37.1.9	Uncharacterized protein of 98 aas and 1 TMS		*UP of Cellulosimicrobium* sp. BI34T**