TABLE 1.

Relative MIC^a values of mutant peptides that have been altered in the central helix and hinge region, assayed against four different indicator strains

Mutated peptide	Fold change in activity against each indicator strain with indicated peptide substitutionb
	Gln	Leu	Ala	Ser	Trp	His	Phe	Tyr	Asn	Glu	Asp
Trp16		>200				>300, 400, 100, 90	30, 30, 30, 20	60, 50, 70, 20
Arg19		80, 60, 200, 100			50, 3, 70, 30
Gly20			1, 1, 2, 2	1, 1, 2, 1
Glu21	20, 20, 10, 10										90, 70, 60, 20
Ala22		2, 1, 2, 1		40, 40, 30, 8
Thr23	70, 50, 100, 100	40, 40, 30, 30
Gln24									10, 10, 9, 6	10, 20, 20, 9
Ser25	60, 50, 80, 50	80, 200, 200, 100
Gly28	≥400	>400	10, 10, 40, 8	≥300

^aThe relative MICs are the MIC of the mutant peptide divided by the MIC of wild-type curvacin A. The MIC is defined as the amount of bacteriocin that inhibited the growth by 50%. Four different indicator strains, C. piscicola UI 49 (LMGT 2332), L. coryniformis subsp. torquens (NCDO 2740), E. faecalis (NCDO 581), and L. sake (NCDO 2714), were used. MIC for wild-type curvacin A was 0.05 nM when assayed against C. piscicola UI 49; 0.07 nM when assayed against E. faecalis; and 0.08 nM when assayed against L. coryniformis subsp. torquens and L. sake. Standard deviations were less than 30% of the MIC for 50% of the measurements, less than 50% for 80% of the measurements, and less than 75% for 97% of the measurements.

^bWhere four relative MICs are reported, these values represent results obtained with the following indicator strains, C. piscicola UI 49, L. coryniformis subsp. torquens, E. faecalis, and L. sake, respectively. Where only one relative MIC value is reported, this value represents results for all four indicator strains.