alpha,beta -> beta,gamma double bond migration in corallopyronin A biosynthesis

Titlealpha,beta -> beta,gamma double bond migration in corallopyronin A biosynthesis
Publication TypeJournal Article
Year of Publication2013
AuthorsLohr F., Jenniches I., Frizler M., Meehan M.J, Sylvester M., Schmitz A., Gutschow M., Dorrestein PC, Konig G.M, Schaberle T.F
JournalChemical Science
Date Published2013/08
Type of ArticleArticle
ISBN Number2041-6520
Accession NumberWOS:000325409500010
Keywordsactinosynnema-pretiosum; ansamitocin; bacillus-subtilis; carrier domains; gene-cluster; mass-spectrometry; polyketide synthase

In polyketide biosynthesis the reduction of beta-carbonyl groups to an alkene usually results in a alpha,beta double bond. However, in a few antibiotics the rare case of such a carbon-carbon double bond in beta,gamma position is observed. The in vivo active antibiotic corallopyronin A represents such a molecule, whereby a alpha,beta -> beta,gamma double bond migration takes place during the assembly of the molecule. Here we report the in vitro analysis of the enzyme domain responsible for this double bond isomerization. This "shift domain" was heterologously expressed and assayed with its acyl carrier protein bound substrate. To facilitate this analysis the biosynthetic corallopyronin A intermediate was chemically synthesized as a SNAC-derivative. Enzyme activity was analyzed by NMR and high-resolution MS measurements, the latter enabled by performing the assay in deuterated buffer. Mutated enzyme variants gave first experimental evidence for the essential amino acids involved in double bond migration. These results further support the proposed corallopyronin A biosynthesis.

Short TitleChem. Sci.
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