title: Pristinamycin I biosynthesis in Streptomyces pristinaespiralis: molecular characterization of the first two structural peptide synthetase genes.
abstract: Two genes involved in the biosynthesis of the depsipeptide antibiotics pristinamycins I (PI) produced by Streptomyces pristinaespiralis were cloned and sequenced. The 1.7-kb snbA gene encodes a 3-hydroxypicolinic acid:AMP ligase, and the 7.7-kb snbC gene encodes PI synthetase 2, responsible for incorporating L-threonine and L-aminobutyric acid in the PI macrocycle. snbA and snbC, which encode the two first structural enzymes of PI synthesis, are not contiguous. Both genes are located in PI-specific transcriptional units, as disruption of one gene or the other led to PI-deficient strains producing normal levels of the polyunsaturated macrolactone antibiotic pristinamycin II, also produced by S. pristinaespiralis. Analysis of the deduced amino acid sequences showed that the SnbA protein is a member of the adenylate-forming enzyme superfamily and that the SnbC protein contains two amino acid-incorporating modules and a C-terminal epimerization domain. A model for the initiation of PI synthesis analogous to the established model of initiation of fatty acid synthesis is proposed.
authors.affiliation: Division Recherche Pharmaceutique, Centre de Recherche de Vitry-Alfortville, Rhône Poulenc Rorer S.A., Vitry-sur-Seine, France. vcrecy@pasteur.fr
authors.forename: V
authors.initials: V
authors.lastname: de Crécy-Lagard
authors.forename: V
authors.initials: V
authors.lastname: Blanc
authors.forename: P
authors.initials: P
authors.lastname: Gil
authors.forename: L
authors.initials: L
authors.lastname: Naudin
authors.forename: S
authors.initials: S
authors.lastname: Lorenzon
authors.forename: A
authors.initials: A
authors.lastname: Famechon
authors.forename: N
authors.initials: N
authors.lastname: Bamas-Jacques
authors.forename: J
authors.initials: J
authors.lastname: Crouzet
authors.forename: D
authors.initials: D
authors.lastname: Thibaut
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins; D001665:Binding Sites; D003001:Cloning, Molecular; D003609:Dactinomycin / Q000096:biosynthesis; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010453:Peptide Synthases / Q000096:biosynthesis / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000235:genetics*; D014769:Virginiamycin / Q000096:biosynthesis*
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D011994:Recombinant Proteins; D014769:Virginiamycin; D003609:Dactinomycin; D010453:Peptide Synthases; C104048:SnbA protein, Streptomyces pristinaespiralis; C104049:SnbC protein, Streptomyces pristinaespiralis