Polyketide-chain branching by an enzymatic Michael addition

Angew Chem Int Ed Engl. 2009;48(27):5001-4. doi: 10.1002/anie.200900277.


A new "branch" for polyketide synthases was discovered in the biosynthesis of the antimitotic rhizoxin complex in the endofungal bacterium Burkholderia rhizoxinica. Genetic engineering and the structural elucidation of pathway intermediates revealed that a complex polyketide chain is branched at the beta position by an unprecedented conjugate addition of an acetyl building block to an acryloyl precursor (see scheme).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry*
  • Biocatalysis
  • Burkholderia / enzymology
  • Gene Knockout Techniques
  • Macrolides / chemistry*
  • Multigene Family
  • Polyketide Synthases / genetics
  • Polyketide Synthases / metabolism*
  • Protein Structure, Tertiary


  • Antineoplastic Agents
  • Macrolides
  • Polyketide Synthases
  • rhizoxin