title: Toxic and non-toxic strains of the cyanobacterium Microcystis aeruginosa contain sequences homologous to peptide synthetase genes.
abstract: Toxic strains of Microcystis aeruginosa produce cyclic heptatoxins (microcystins) that are believed to be synthesized non-ribosomally by peptide synthetases. We analysed toxin-producing and non-toxic strains of M. aeruginosa with respect to the presence of DNA sequences potentially encoding peptide synthetases. Hybridizations of genomic DNA of various M. aeruginosa strains with PCR-amplificated fragments possessing homologies to adenylate-forming domains of peptide synthetase genes provided first evidence for the existence of corresponding genes in cyanobacteria. Furthermore we isolated and sequenced from genomic libraries overlapping fragments of M. aeruginosa DNA with a total length of 2982 bp showing significant homology to genes encoding peptide synthetases and hybridizing exclusively with DNA from toxic strains. Our results indicate that both toxic and non-toxic strains of M. aeruginosa possess genes coding for peptide synthetases and that hepatotoxin-producing and non-toxic strains differ in their content of genes for specific peptide synthetases.
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Meissner
authors.forename: E
authors.initials: E
authors.lastname: Dittmann
authors.forename: T
authors.initials: T
authors.lastname: Börner
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001427:Bacterial Toxins; D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D046931:Microcystis / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010453:Peptide Synthases / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; C098564:MAPEP1 protein, Microcystis aeruginosa; D010453:Peptide Synthases