Genetic analysis of polyketide synthase and peptide synthetase genes in cyanobacteria as a mining tool for secondary metabolites

  • Martin E. Barrios-Llerena
  • Adam M. Burja
  • Phillip C. Wright
Original Paper

DOI: 10.1007/s10295-007-0216-6

Cite this article as:
Barrios-Llerena, M.E., Burja, A.M. & Wright, P.C. J Ind Microbiol Biotechnol (2007) 34: 443. doi:10.1007/s10295-007-0216-6

Abstract

Molecular screening using degenerate PCR to determine the presence of secondary metabolite genes in cyanobacteria was performed. This revealed 18 NRPS and 19 PKS genes in the 21 new cyanobacterial strains examined, representing three families of cyanobacteria (Nostocales, Chroococales and Oscillatoriales). A BLAST analysis shows that these genes have similarities to known cyanobacterial natural products. Analysis of the NRPS adenylation domain indicates the presence of novel features previously ascribed to both proteobacteria and cyanobacteria. Furthermore, binding-pocket predictions reveal diversity in the amino acids used during the biosynthesis of compounds. A similar analysis of the PKS ketosynthase domain shows significant structural diversity and their presence in both mixed modules with NRPS domains and individually as part of a PKS module. We have been able to classify the NRPS genes on the basis of their binding-pockets. Further, we show how this data can be used to begin to link structure to function by an analysis of the compounds Scyptolin A and Hofmannolin from Scytonema sp. PCC 7110.

Keywords

Peptide synthetases Polyketide synthases Cyanobacteria Ketosynthase domain Adenylation domain Natural products 

Supplementary material

10295_2007_216_MOESM1_ESM.doc (41 kb)
Figure 1. Alignment of the active sites of type I ketosynthase (KS) domains with distinct functions. Conserved residues are highlighted in black. Residues conserved within each functional group are highlighted in gray. (A) Representatives of KS domains specific for amino acid starter units in mixed or hybrid systems. Sequences included here are BarE from Lyngbya majuscula (accession No. AAN32979.1), NosB from Nostoc sp. (accession No. AF204805), EposB from Sorangium cellulosum (accession No. AF217189), MtaD from Stigmatella aurantiaca (accession No. AAF19812), and BlmVIII from Streptomyces verticillus (accession No. AAG02357). (B) Representatives of type I KS domain, sequences analysed included MycD and E from Microcystis aeruginosa (accession No. AF183408), JamE from Lyngbya majuscula (accession No. AY522504), CurA, I and F from Lyngbya majuscula (accession No. AY652953), EposA and D from Sorangium cellulosum (accession No. AF217189), and LnmI from Streptomyces atroolivaceus (accession No. AF484556). The Type I fatty acid synthase KS domain sequence from Escherichia coli (accession No. 6573501) is also given as a comparison and the consensus sequence is shown. (DOC 41 kb)

Copyright information

© Society for Industrial Microbiology 2007

Authors and Affiliations

  • Martin E. Barrios-Llerena
    • 1
    • 3
  • Adam M. Burja
    • 2
  • Phillip C. Wright
    • 1
  1. 1.Biological and Environmental Systems Group, Department of Chemical and Process EngineeringUniversity of SheffieldSheffieldUK
  2. 2.Metabolic Engineering and Fermentation Group, Ocean Nutrition CanadaDartmouthCanada
  3. 3.Marie Curie Excellence Team Pathogen Habitats, Institute of Immunology and Infection ResearchUniversity of EdinburghEdinburghUK

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