2leu

HIGH RESOLUTION 1H NMR STUDY OF LEUCOCIN A IN 90% AQUEOUS TRIFLUOROETHANOL (TFE) (0.1% TFA), 18 STRUCTURES

spinqualitylabelsall models 2leu, 18 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2leu is a 1 chain structure with sequence from Leuconostoc gelidum. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, RCSB, PDBsum Function [LCCA_LEUGE] Inhibits a wide spectrum of lactic acid bacteria. Publication Abstract from PubMed The first three-dimensional structure of a type IIa bacteriocin from lactic acid bacteria is reported. Complete 1H resonance assignments of leucocin A, a 37 amino acid antimicrobial peptide isolated from the lactic acid bacterium Leuconostoc gelidum UAL187, were determined in 90% trifluoroethanol (TFE)-water and in aqueous dodecylphosphocholine (DPC) micelles (1:40 ratio of leucocin A:DPC) using two-dimensional NMR techniques (e.g., DQF-COSY, TOCSY, NOESY). Circular dichroism spectra, NMR chemical shift indices, amide hydrogen exchange rates, and long-range nuclear Overhauser effects indicate that leucocin A adopts a reasonably well defined structure in both TFE and DPC micelle environments but exists as a random coil in water or aqueous DMSO. Distance geometry and simulated annealing calculations were employed to generate structures for leucocin A in both lipophilic media. While some differences were noted between the structures calculated for the two different solvent systems, in both, the region encompassing residues 17-31 assumes an essentially identical amphiphilic alpha-helix conformation. A three-strand antiparallel beta-sheet domain (residues 2-16), anchored by the disulfide bridge, is also observed in both media. In TFE, these two regions have a more defined relationship relative to each other, while, in DPC micelles, the C-terminus is folded back onto the alpha-helix. The implications of these structural features with regard to the antimicrobial mechanism of action and target recognition are discussed. Three-dimensional structure of leucocin A in trifluoroethanol and dodecylphosphocholine micelles: spatial location of residues critical for biological activity in type IIa bacteriocins from lactic acid bacteria.,Fregeau Gallagher NL, Sailer M, Niemczura WP, Nakashima TT, Stiles ME, Vederas JC Biochemistry. 1997 Dec 9;36(49):15062-72. PMID:9398233 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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