1og7
From Proteopedia
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THREE-DIMENSIONAL STRUCTURE IN LIPID MICELLES OF THE PEDIOCIN-LIKE ANTIMICROBIAL PEPTIDE SAKACIN P.
Overview
The three-dimensional structures in dodecylphosphocholine (DPC) micelles, and in trifluoroethanol (TFE) of the pediocin-like antimicrobial peptide, sakacin P and an engineered variant of sakacin P (termed sakP[N24C+44C]), have been determined by use of nuclear magnetic resonance spectroscopy., SakP[N24C+44C] has an inserted non-native activity- and, structure-stabilizing C-terminal disulfide bridge that ties the C-terminus, to the middle part of the peptide. In the presence of DPC, the cationic, N-terminal region (residues 1-17) of both peptides has an S-shaped, conformation that is reminiscent of a three-stranded antiparallel, beta-sheet and that is more pronounced when the peptide was dissolved in, TFE instead of DPC. The four positively charged residues located in the, N-terminal part are found pointing to the same direction. For both, peptides, the N-terminal region is followed by a well-defined central, amphiphilic alpha-helix (residues 18-33), and this in turn is followed by, the C-terminal tail (residues 34-43 for sakacin P and 34-44 for, sakP[N24C+44C]) that lacks any apparent common secondary structural motif., In the presence of DPC, the C-terminal tails in both peptides fold back, onto the central alpha-helix, thereby creating a hairpin-like structure in, the C-terminal halves. The lack of long-range NOEs between the beta-sheet, Nu-terminal region and the hairpin-like C-terminal half indicates that, there is a flexible hinge between these regions. We discuss which, implications such a structural arrangement has on the interaction with the, target cell membrane.
About this Structure
1OG7 is a Single protein structure of sequence from Lactobacillus sakei. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure in lipid micelles of the pediocin-like antimicrobial peptide sakacin P and a sakacin P variant that is structurally stabilized by an inserted C-terminal disulfide bridge., Uteng M, Hauge HH, Markwick PR, Fimland G, Mantzilas D, Nissen-Meyer J, Muhle-Goll C, Biochemistry. 2003 Oct 7;42(39):11417-26. PMID:14516192
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