Editing Bacteriocin (section)

===From Gram positive bacteria===

Bacteriocins from Gram positive bacteria are typically classified into Class I, Class IIa/b/c, and Class III.
<ref>{{cite journal | vauthors = Cotter PD, Hill C, Ross RP |title=What's in a name? Class distinction for bacteriocins |journal=Nature Reviews Microbiology |date=February 2006 |volume=4 |issue=2 |pages=160 |doi=10.1038/nrmicro1273-c2 |s2cid=29421506 |doi-access=free }} is author reply to comment on article :{{cite journal | vauthors = Cotter PD, Hill C, Ross RP | title = Bacteriocins: developing innate immunity for food | journal = Nature Reviews. Microbiology | volume = 3 | issue = 10 | pages = 777–88 | date = October 2005 | pmid = 16205711 | doi = 10.1038/nrmicro1273 | s2cid = 19040535 }}</ref>

====Class I bacteriocins====
The [[lantibiotics|class I bacteriocins]] are small peptide inhibitors and include [[nisin]] and other [[lantibiotic]]s.

====Class II bacteriocins====
The [[class II bacteriocins]] are small (<10 kDa) heat-stable proteins. This class is subdivided into five subclasses. The class IIa bacteriocins (pediocin-like bacteriocins) are the largest subgroup and contain an [[N-terminus|N-terminal]] consensus sequence -Tyr-Gly-Asn-Gly-Val-Xaa-Cys across this group.<ref>{{Cite journal |last1=Zhu |first1=Liyan |last2=Zeng |first2=Jianwei |last3=Wang |first3=Chang |last4=Wang |first4=Jiawei |date=2022-02-08 |title=Structural Basis of Pore Formation in the Mannose Phosphotransferase System by Pediocin PA-1 |journal=Applied and Environmental Microbiology |volume=88 |issue=3 |pages=e0199221 |doi=10.1128/AEM.01992-21 |issn=1098-5336 |pmc=8824269 |pmid=34851716}}</ref><ref>{{Cite journal |last1=Zhu |first1=Liyan |last2=Zeng |first2=Jianwei |last3=Wang |first3=Jiawei |date=2022-06-15 |title=Structural Basis of the Immunity Mechanisms of Pediocin-like Bacteriocins |journal=Applied and Environmental Microbiology |volume=88 |issue=13 |pages=e0048122 |doi=10.1128/aem.00481-22 |issn=1098-5336 |pmid=35703550|pmc=9275228 }}</ref> The C-terminal is responsible for species-specific activity, causing cell-leakage by permeabilizing the target cell wall.

:Class IIa bacteriocins have a large potential for use in [[food preservation]] as well medical applications due to their strong anti-''[[Listeria]]'' activity and broad range of activity. One example of Class IIa bacteriocin is ''pediocin PA-1''.<ref>{{cite book |doi=10.1007/978-3-540-36604-1_4 |chapter=The Diversity of Bacteriocins in Gram-Positive Bacteria |title=Bacteriocins |year=2007 | vauthors = Heng NC, Wescombe PA, Burton JP, Jack RW, Tagg JR |pages=45–92 |isbn=978-3-540-36603-4 }}</ref>
:The class IIb bacteriocins (two-peptide bacteriocins) require two different peptides for activity.  One such an example is ''lactococcin G'', which permeabilizes cell membranes for monovalent [[sodium]] and [[potassium]] cations, but not for divalent cations. Almost all of these bacteriocins have a GxxxG motifs. This motif is also found in [[transmembrane protein]]s, where they are involved in helix-helix interactions. Accordingly, the bacteriocin GxxxG motifs can interact with the motifs in the membranes of the bacterial cells, killing the cells.<ref>{{cite journal | vauthors = Nissen-Meyer J, Rogne P, Oppegård C, Haugen HS, Kristiansen PE | title = Structure-function relationships of the non-lanthionine-containing peptide (class II) bacteriocins produced by gram-positive bacteria | journal = Current Pharmaceutical Biotechnology | volume = 10 | issue = 1 | pages = 19–37 | date = January 2009 | pmid = 19149588 | doi = 10.2174/138920109787048661 }}</ref>
:Class IIc encompasses [[cyclic peptide]]s, in which the N-terminal and [[C-terminus|C-terminal]] regions are covalentely linked. ''Enterocin AS-48'' is the prototype of this group.
:Class IId cover single-peptide bacteriocins, which are not post-translationally modified and do not show the pediocin-like signature. The best example of this group is the highly stable ''aureocin A53''. This bacteriocin is stable under highly acidic conditions, high temperatures, and is not affected by [[protease]]s.<ref>{{cite journal | vauthors = Netz DJ, Pohl R, Beck-Sickinger AG, Selmer T, Pierik AJ, Bastos M, Sahl HG | title = Biochemical characterisation and genetic analysis of aureocin A53, a new, atypical bacteriocin from Staphylococcus aureus | journal = Journal of Molecular Biology | volume = 319 | issue = 3 | pages = 745–56 | date = June 2002 | pmid = 12054867 | doi = 10.1016/S0022-2836(02)00368-6 }}</ref>

The most recently proposed subclass is the Class IIe, which encompasses those bacteriocins composed of three or four non-pediocin like peptides. The best example is ''aureocin A70'', a four-peptide bacteriocin, highly active against ''[[Listeria monocytogenes]]'', with potential biotechnological applications.<ref>{{cite journal | vauthors = Netz DJ, Sahl HG, Marcelino R, dos Santos Nascimento J, de Oliveira SS, Soares MB, do Carmo de Freire Bastos M, Marcolino R | display-authors = 6 | title = Molecular characterisation of aureocin A70, a multi-peptide bacteriocin isolated from Staphylococcus aureus | journal = Journal of Molecular Biology | volume = 311 | issue = 5 | pages = 939–49 | date = August 2001 | pmid = 11531330 | doi = 10.1006/jmbi.2001.4885 }}</ref> Recent work has identified that these bacteriocins are widespread across the bacterial domain and are present in the phylum [[Actinomycetota]]. <ref>{{Cite journal |last=Hourigan |first=David |last2=Miceli de Farias |first2=Felipe |last3=O’Connor |first3=Paula M. |last4=Hill |first4=Colin |last5=Ross |first5=R. Paul |date=2024-10-15 |editor-last=Galperin |editor-first=Michael Y. |title=Discovery and synthesis of leaderless bacteriocins from the Actinomycetota |url=https://journals.asm.org/doi/10.1128/jb.00298-24 |journal=Journal of Bacteriology |language=en |doi=10.1128/jb.00298-24 |issn=0021-9193|doi-access=free |pmc=11580447 }}</ref>

====Class III bacteriocins====
Class III bacteriocins are large, heat-labile (>10 kDa) protein bacteriocins. This class is subdivided in two subclasses: subclass IIIa (bacteriolysins) and subclass IIIb. 
Subclass IIIa comprises those peptides that kill bacterial cells by [[Cell wall#Bacterial cell walls|cell wall]] degradation, thus causing cell lysis. The best studied bacteriolysin is [[lysostaphin]], a 27 kDa peptide that hydrolyzes the cell walls of several ''Staphylococcus'' species, principally ''[[Staphylococcus aureus|S. aureus]]''.<ref>{{cite journal | vauthors = Bastos MD, Coutinho BG, Coelho ML | title = Lysostaphin: A Staphylococcal Bacteriolysin with Potential Clinical Applications | journal = Pharmaceuticals | volume = 3 | issue = 4 | pages = 1139–1161 | date = April 2010 | pmid = 27713293 | pmc = 4034026 | doi = 10.3390/ph3041139 | doi-access = free }}</ref> Subclass IIIb, in contrast, comprises those peptides that do not cause cell lysis, killing the target cells by disrupting plasma membrane potential.

====Class IV bacteriocins====
Class IV bacteriocins are defined as complex bacteriocins containing [[lipid]] or [[carbohydrate]] moieties. 
Confirmation by experimental data was established with the characterisation of sublancin and glycocin F (GccF) by two independent groups.<ref>{{cite journal | vauthors = Oman TJ, Boettcher JM, Wang H, Okalibe XN, van der Donk WA | title = Sublancin is not a lantibiotic but an S-linked glycopeptide | journal = Nature Chemical Biology | volume = 7 | issue = 2 | pages = 78–80 | date = February 2011 | pmid = 21196935 | pmc = 3060661 | doi = 10.1038/nchembio.509 }}</ref><ref>{{cite journal | vauthors = Stepper J, Shastri S, Loo TS, Preston JC, Novak P, Man P, Moore CH, Havlíček V, Patchett ML, Norris GE | display-authors = 6 | title = Cysteine S-glycosylation, a new post-translational modification found in glycopeptide bacteriocins | journal = FEBS Letters | volume = 585 | issue = 4 | pages = 645–50 | date = February 2011 | pmid = 21251913 | doi = 10.1016/j.febslet.2011.01.023 | s2cid = 29992601 }}</ref>