title: Jahnellamides, α-keto-β-methionine-containing peptides from the terrestrial myxobacterium Jahnella sp.: structure and biosynthesis.
abstract: Two new cyclic peptides, termed jahnellamides A and B, were isolated from the myxobacterium Jahnella sp. Their structures were solved by NMR, ESIMS, and chemical derivatizations. Jahnellamides are a new class of α-ketoamide-containing peptides comprised of nonproteinogenic amino acids, including α-keto-β-methionine and 4-hydroxyglutamic acid. Moreover, in silico analysis of the genome sequence along with feeding experiments allowed us to identify and annotate a candidate nonribosomal peptide synthetase biosynthetic gene cluster containing a polyketide synthase module involved in the formation of the α-ketoamide moiety.
authors.affiliation: Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Pharmaceutical Biotechnology, Saarland University , Campus C2 3, 66123 Saarbrücken, Germany.
authors.forename: Alberto
authors.initials: A
authors.lastname: Plaza
authors.forename: Konrad
authors.initials: K
authors.lastname: Viehrig
authors.forename: Ronald
authors.initials: R
authors.lastname: Garcia
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
mesh_terms: D005971:Glutamates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008715:Methionine / Q000737:chemistry*; D015394:Molecular Structure; D010453:Peptide Synthases / Q000096:biosynthesis* / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D005971:Glutamates; D010455:Peptides; D010456:Peptides, Cyclic; C587753:jahnellamide A; C587754:jahnellamide B; C011859:hydroxyglutamic acid; D008715:Methionine; D010453:Peptide Synthases