|Title||Nonlinear biosynthetic assembly of alpiniamide by a hybrid cis/trans-AT PKS-NRPS|
|Publication Type||Journal Article|
|Year of Publication||2020|
|Authors||Sigrist R., Luhavaya H., McKinnie S.MK, da Silva A.F, Jurberg I.D, Moore BS, de Oliveira L.G|
|Type of Article||Article|
|Keywords||acid; acyltransferase; bacterial; Biochemistry & Molecular Biology; direct cloning; gene-cluster; heterologous expression; i polyketide synthase; natural-product discovery; organization; thiolactomycin|
Alpiniamide A is a linear polyketide produced by Stieptomyces endophytic bacteria. Despite its relatively simple chemical structure suggestive of a linear assembly line biosynthetic construction involving a hybrid polyketide synthase-nonribosomal peptide synthetase enzymatic protein machine, we report an unexpected nonlinear synthesis of this bacterial natural product. Using a combination of genomics, heterologous expression, mutagenesis, isotope-labeling, and chain terminator experiments, we propose that alpiniamide A is assembled in two halves and then ligated into the mature molecule. We show that each polyketide half is constructed using orthogonal biosynthetic strategies, employing either cis- or trans-acyl transferase mechanisms, thus prompting an alternative proposal for the operation of this PKS-NRPS.