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1.C.93 The Lacticin Q (Lacticin Q) Family

Lacticin Q is a peptide-lipid huge toroidal pore-forming bacteriocin produced by Lactococcus lactis QU 5 with antimicrobial activity in the nanomolar range. Lacticin Q induced calcein leakage from negatively charged liposomes. Concomitantly with calcein leakage, lacticin Q translocates from the outer to the inner leaflet of the liposomes within two seconds after initially binding to membrane. Lacticin Q also induced lipid flip-flop. Yoneyama et al., 2009 provided the first evidence for a bacteriocin from Gram-positive bacteria forming a toroidal pore. From liposomes, lacticin Q leaked fluorescence-labeled dextran with a diameter of 4.6 nm and caused leakage of small size proteins such as green fluorescence protein from live bacterial cells. The proposed pore formation model of lacticin Q is as follows: (i) quick binding to outer membrane leaflets; (ii) formation of at least 4.6 nm pores, causing protein leakage with lipid flip-flop, and (iii) migration of lacticin Q molecules from the outer to the inner membrane leaflet.

References associated with 1.C.93 family:

Draper, L.A., P.D. Cotter, C. Hill, and R.P. Ross. (2015). Lantibiotic resistance. Microbiol. Mol. Biol. Rev. 79: 171-191. 25787977
Yoneyama F., Imura Y., Ohno K., Zendo T., Nakayama J., Matsuzaki K. and Sonomoto K. (2009). Peptide-lipid huge toroidal pore, a new antimicrobial mechanism mediated by a lactococcal bacteriocin, lacticin Q. Antimicrob Agents Chemother. 53(8):3211-7. 19470516