title: Three-dimensional structure in lipid micelles of the pediocin-like antimicrobial peptide curvacin A.
abstract: The 3D structure of the membrane-permeabilizing 41-mer pediocin-like antimicrobial peptide curvacin A produced by lactic acid bacteria has been studied by NMR spectroscopy. In DPC micelles, the cationic and hydrophilic N-terminal half of the peptide forms an S-shaped beta-sheet-like domain stabilized by a disulfide bridge and a few hydrogen bonds. This domain is followed by two alpha-helices: a hydrophilic 6-mer helix between residues 19 and 24 and an amphiphilic/hydrophobic 11-mer helix between residues 29 and 39. There are two hinges in the peptide, one at residues 16-18 between the N-terminal S-shaped beta-sheet-like structure and the central 6-mer helix and one at residues 26-28 between the central helix and the 11-mer C-terminal helix. The latter helix is the only amphiphilic/hydrophobic part of the peptide and is thus presumably the part that penetrates into the hydrophobic phase of target-cell membranes. The hinge between the two helices may introduce the flexibility that allows the helix to dip into membranes. The helix-hinge-helix structure in the C-terminal half of curvacin A clearly distinguishes this peptide from the other pediocin-like peptides whose structures have been analyzed and suggests that curvacin A along with the structural homologues enterocin P and carnobacteriocin BM1 belong to a subgroup of the pediocin-like family of antimicrobial peptides.
authors.affiliation: Department of Molecular Biosciences, University of Oslo, Pb. 1041 Blindern, 0316 Oslo, Norway.
authors.forename: Helen Sophie
authors.initials: HS
authors.lastname: Haugen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Fimland
authors.forename: Jon
authors.initials: J
authors.lastname: Nissen-Meyer
authors.forename: Per Eugen
authors.initials: PE
authors.lastname: Kristiansen
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism; D001430:Bacteriocins / Q000737:chemistry* / Q000378:metabolism; D007778:Lactobacillus / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008823:Micelles; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D023181:Antimicrobial Cationic Peptides; D001430:Bacteriocins; D008055:Lipids; D008823:Micelles; C071456:sakacin A