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)
Cyclic bacteriocin, Group I, Lactocyclicin Q (LycQ, 63 aas; 1 TMS) (Sawa et al., 2009; van Belkum et al., 2011)
LcyQ of Lactococcus sp-strain QU12 (B9ZZY0)
The Lactocyclin homologue
Lactocyclicin homologue of Streptococcus mutans (C6STH0)
Uncharacterized protein of 85 aas and 2 TMSs
UP of Streptococcus macacae
Bacteriocin cerein 7B family protein of 91 aas and 2 TMSs
Bacteriocin of Streptococcus sobrinus
Putative toxic protein of 91 aas and 2 TMSs
Toxin of Pseudoxanthomonas sp.
Uncharacterized protein of 117 aas and 2 TMSs
UP of Xenorhabdus bovienii
Uncharacterized protein of 96 aas and 1 TMS.
UP of Yokenella regensburgei
Uncharacterized protein of 72 aas and 2 TMSs.
UP of Xanthomonas albilineans