title: Cyclic lipoundecapeptide amphisin from Pseudomonas sp. strain DSS73.
abstract: The crystal structure of the lipoundecapeptide amphisin, presented here as the tetrahydrate, C(66)H(114)N(12)O(20).4H(2)O, originating from non-ribosomal biosynthesis by Pseudomonas sp. strain DSS73, has been solved to a resolution of 0.65 A. The primary structure of amphisin is beta-hydroxydecanoyl-D-Leu-D-Asp-D-allo-Thr-D-Leu-D-Leu-D-Ser-L-Leu-D-Gln-L-Leu-L-Ile-L-Asp (Leu is leucine, Asp is aspartic acid, Thr is threonine, Ser is serine, Gln is glutamine and Ile is isoleucine). The peptide is a lactone, linking Thr4 O(gamma) to the C-terminal. The stereochemistry of the beta-hydroxy acid is R. The peptide is a close analogue of the cyclic lipopeptides tensin and pholipeptin produced by Pseudomonas fluorescens. The structure of amphisin is mainly helical (3(10)-helix), with the cyclic peptide wrapping around a hydrogen-bonded water molecule. This lipopeptide is amphiphilic and has biosurfactant and antifungal properties.
authors.affiliation: Marine Chemistry Section, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Sørensen
authors.forename: T H
authors.initials: TH
authors.lastname: Nielsen
authors.forename: C
authors.initials: C
authors.lastname: Christophersen
authors.forename: J
authors.initials: J
authors.lastname: Sørensen
authors.forename: M
authors.initials: M
authors.lastname: Gajhede
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D018360:Crystallography, X-Ray; D008074:Lipoproteins / Q000737:chemistry / Q000302:isolation & purification; D008958:Models, Molecular; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification; D011487:Protein Conformation; D011549:Pseudomonas / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D010456:Peptides, Cyclic; C438267:amphisin