1.C.53 The Lactocyclicin Q (Lactocyclicin Q) Family

Lactococcus sp. strain QU 12, isolated from cheese, produces a cyclic bacteriocin termed lactocyclicin Q (Sawa et al., 2009). Lactocyclicin Q was purified from culture supernatant and has a unique antimicrobial spectrum, high level of protease resistance, and heat stability compared to other reported bacteriocins of lactic acid bacteria. This compound is composed of 61 aas that have a cyclic structure with linkage between the N and C termini by a peptide bond. It shows little similarity to any other antimicrobial peptides, including cyclic bacteriocins, but shows significant similarity to small proteins from Bacillus coagulans (EEN93214; 38% identity) and Paenibacillus larvae (ZP_02326427; 36% identity). It has a single TMS.

The reaction presumed to be catalyzed by Lactocyclicin Q is:

ions (in) ⇌ ions (out)



This family belongs to the Bacterial Bacteriocin (BB) Superfamily.

 

References:

Sawa, N., T. Zendo, J. Kiyofuji, K. Fujita, K. Himeno, J. Nakayama, and K. Sonomoto. (2009). Identification and characterization of lactocyclicin Q, a novel cyclic bacteriocin produced by Lactococcus sp. strain QU 12. Appl. Environ. Microbiol. 75: 1552-1558.

van Belkum, M.J., L.A. Martin-Visscher, and J.C. Vederas. (2011). Structure and genetics of circular bacteriocins. Trends Microbiol. 19: 411-418.

Wescombe, P.A., M. Upton, P. Renault, R.E. Wirawan, D. Power, J.P. Burton, C.N. Chilcott, and J.R. Tagg. (2011). Salivaricin 9, a new lantibiotic produced by Streptococcus salivarius. Microbiology 157: 1290-1299.

Examples:

TC#NameOrganismal TypeExample
1.C.53.1.1

Cyclic bacteriocin, Group I, Lactocyclicin Q (LycQ, 63 aas; 1 TMS) (Sawa et al., 2009van Belkum et al., 2011)

Firmicutes

LcyQ of Lactococcus sp-strain QU12 (B9ZZY0)

 
1.C.53.1.2

The Lactocyclin homologue

Firmicutes

Lactocyclicin homologue of Streptococcus mutans (C6STH0)

 
1.C.53.1.3

Uncharacterized protein of 85 aas and 2 TMSs

UP of Streptococcus macacae

 
1.C.53.1.4

Bacteriocin cerein 7B family protein of 91 aas and 2 TMSs

Bacteriocin of Streptococcus sobrinus

 
1.C.53.1.5

Putative toxic protein of 91 aas and 2 TMSs

Toxin of Pseudoxanthomonas sp.

 
1.C.53.1.6

Uncharacterized protein of 117 aas and 2 TMSs

UP of Xenorhabdus bovienii

 
1.C.53.1.7

Uncharacterized protein of 96 aas and 1 TMS. 

UP of Yokenella regensburgei

 
1.C.53.1.8

Uncharacterized protein of 72 aas and 2 TMSs.

UP of Xanthomonas albilineans