Table 1. List of circular and leaderless bacteriocins that adopt a saposin-like fold or a helical-bundle.

Bacteriocin	Producing organism	Circular (C) or leaderless (L) bacteriocin	No. of residues	Net charge at pH 7	Activity spectrum	Secondary structural motif	Reference
Circularin A a	Geobacillus kaustophilus	C	76	+1	br. Gr.+	Saposin-like	44
Uberolysin a	Streptococcus uberis	C	70	+3	br. Gr.+	Saposin-like	45
Enterocin AS-48 b	Enterocin feacalis	C	70	+6	br. Gr.+	Saposin-like	36
NKR-5-3B c	Enterococcus faecalis	C	64	+5	br. Gr.+	Saposin-like	40
Pneumocyclicin d	Streptococcus pneumoniae	C	64	+5	N/A	Saposin-like	74
Leucocyclicin Q d	Leuconostoc mesenteroides	C	63	+3	br. Gr.+	Saposin-like	48
Lactocyclicin Q a	Lactococcus sp.	C	61	+4	br. Gr.+	Saposin-like	49
Garvicin ML d	Lactococcus garvieae	C	60	+5	br. Gr.+	Saposin-like	46
Carnocyclin A e	Carnobacterium maltaromaticum	C	60	+4	br. Gr.+ *nw. Gr.–	Saposin-like	43
Amylocyclicin d	Bacillus amyloliquefaciens	C	60	+3	Gr.+	Saposin-like	47
Aureocyclicin d	Streptococcus aureus	C	60	+3	N/A	Saposin-like	75
Weissellicin Y e	Weissella hellenica	L	42	+4	br. Gr.+	Saposin-like	76
Weissellicin M e	Weissella hellenica	L	43	+4	br. Gr.+	Saposin-like	76
Lacticin Q f	Lactococcus lactis	L	52	+6	br. Gr.+	Saposin-like	66
Aureocin A53 f	Staphylococcus aureus	L	51	+8	br. Gr.+	Saposin-like	77
Epidermicin NI01 e	Stayphylococcus epidermis	L	51	+8	br. Gr.+	Saposin-like	78
Mutacin BhtB d	Staphylococcus ratti	L	44	+4	br. Gr.+	Saposin-like	79
Enterocin 7A g	Enterococcus faecalis	L	44	+7	br. Gr.+	Saposin-like	37, 80
Enterocin L50A e	Enterococcus faecalis	L	44	+7	br. Gr.+ **nw. Gr.–	Saposin-like	81
Enterocin 7B g	Enterococcus faecalis	L	43	+7	br. Gr.+	Saposin-like	37, 80
Enterocin L50B e	Enterococcus faecalis	L	43	+7	br. Gr.+ **nw. Gr.–	Saposin-like	81
Acidocin B h	Lactobacillus acidophilus	C	59	+1	br. Gr.+	Helical-bundle	82
Gassericin A i	Lactobacillus gasseri	C	59	+1	br. Gr.+	Helical-bundle	50
Butyrivibriocin AR10 i	Butyrivibrio fibriosolvens	C	58	–2	br. Gr.+	Helical-bundle	51

^aStructure modelled and can be found in the main text of ref. 39.

^bStructure experimentally determined by NMR and X-ray crystallography and can be found in ref. 36 and 58.

^cStructure experimentally determined by NMR and can be found in ref. 40.

^dStructure modelled and can be found in the supplementary information attached to this review.

^eStructure modelled and can be found in main text of ref. 38.

^fStructure experimentally determined by NMR and can be found in the main text of ref. 38.

^gStructure experimentally determined by NMR and can be found in the main text of ref. 37.

^hStructure experimentally determined by NMR and can be found in the main text of ref. 41.

ⁱStructure modelled and can be found in main text of ref. 41.