Send to

Choose Destination
See comment in PubMed Commons below
FEBS J. 2007 Jan;274(2):406-17.

A polyketide synthase of Plumbago indica that catalyzes the formation of hexaketide pyrones.

Author information

  • 1Leibniz-Institut für Pflanzenbiochemie, Halle (Saale), Germany.


Plumbago indica L. contains naphthoquinones that are derived from six acetate units. To characterize the enzyme catalyzing the first step in the biosynthesis of these metabolites, a cDNA encoding a type III polyketide synthase (PKS) was isolated from roots of P. indica. The translated polypeptide shared 47-60% identical residues with PKSs from other plant species. Recombinant P. indica PKS expressed in Escherichia coli accepted acetyl-CoA as starter and carried out five decarboxylative condensations with malonyl coenzyme A (-CoA). The resulting hexaketide was not folded into a naphthalene derivative. Instead, an alpha-pyrone, 6-(2',4'-dihydroxy-6'-methylphenyl)-4-hydroxy-2-pyrone, was produced. In addition, formation of alpha-pyrones with linear keto side chains derived from three to six acetate units was observed. As phenylpyrones could not be detected in P. indica roots, we propose that the novel PKS is involved in the biosynthesis of naphthoquinones, and additional cofactors are probably required for the biosynthesis of these secondary metabolites in vivo.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center