[NMR paper] NMR structures and mutational analysis of the two peptides constituting the bacteriocin plantaricin S.

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NMR structures and mutational analysis of the two peptides constituting the bacteriocin plantaricin S.

Related Articles NMR structures and mutational analysis of the two peptides constituting the bacteriocin plantaricin S.

Sci Rep. 2019 02 20;9(1):2333

Authors: Ekblad B, Kristiansen PE

Abstract
The structure of the individual peptides of the two-peptide bacteriocin plantaricin S, an antimicrobial peptide produced by a Lactobacillus plantarum strain, has been determined in DPC micelles. The two peptides of plantaricin S, Pls-? and Pls-?, form an ?-helix from and including residue 8 to 24 with a less structured region around residue 16-19 and an amphiphilic ?-helix from and including residue 7 to 23, respectively. Activity assays on single amino acid-substituted GxxxG and GxxxG-like motifs show that substituting the Ser and Gly residues in the G9xxxG13 motif in Pls-? and the S17xxxG21 motif in Pls-? reduced or drastically reduced the antimicrobial activity. The two-peptide bacteriocin muricidin contains GxxxG-like motifs at similar positions and displays 40-50% amino acid identity with plantaricin S. Activity assays of combinations of the peptides that constitute the bacteriocins plantaricin S and muricidin show that some combinations are highly active. Furthermore, sequence alignments show that the motifs important for plantaricin S activity align with identical motifs in muricidin. Based on sequence comparison and activity assays, a membrane-inserted model of plantaricin S in which the two peptides are oriented antiparallel relative to each other and where the GxxxG and GxxxG-like motifs important for activity come close in space, is proposed.


PMID: 30787405 [PubMed - indexed for MEDLINE]



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