title: Crystal structures of cephaibols.
abstract: The crystal structures of the peptaibol antibiotics cephaibol A, cephaibol B and cephaibol C have been determined at ca. 0.9 A resolution. All three adopt a helical conformation with a sharp bend (of about 55 degrees) at the central hydroxyproline. All isovalines were found to possess the D configuration, superposition of all four models (there are two independent molecules in the cephaibol B structure) shows that the N-terminal helix is rigid and the C-terminus is flexible. There are differences in the hydrogen bonding patterns for the three structures that crystallize in different space groups despite relatively similar unit cell dimensions, but only in the case of cephaibol C does the packing emulate the formation of a membrane channel believed to be important for their biological function.
authors.affiliation: Lehrstuhl für Strukturchemie, Georg-August Universität, Tammannstr. 4, 37077 Göttingen, Germany.
authors.forename: Gábor
authors.initials: G
authors.lastname: Bunkóczi
authors.forename: Matthias
authors.initials: M
authors.lastname: Schiell
authors.forename: László
authors.initials: L
authors.lastname: Vértesy
authors.forename: George M
authors.initials: GM
authors.lastname: Sheldrick
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D023181:Antimicrobial Cationic Peptides; D003460:Crystallization; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry*; D006860:Hydrogen Bonding; D007473:Ion Channels / Q000737:chemistry*; D007476:Ionophores / Q000737:chemistry*; D054848:Peptaibols; D010455:Peptides; D011487:Protein Conformation; D017433:Protein Structure, Secondary
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D005656:Fungal Proteins; D007473:Ion Channels; D007476:Ionophores; D054848:Peptaibols; D010455:Peptides; C491024:cephaibol A; C491025:cephaibol B; C491026:cephaibol C