Polyketide synthases from poison hemlock (Conium maculatum L.).

摘要: Coniine is a toxic alkaloid, the biosynthesis of which not well understood. A possible route, supported by evidence from labelling experiments, involves polyketide formed condensation one acetyl-CoA and three malonyl-CoAs catalysed synthase (PKS). We isolated PKS genes or their fragments poison hemlock (Conium maculatum L.) using random amplification cDNA ends (RACE) transcriptome analysis, characterized full-length enzymes feeding different starter-CoAs in vitro. On basis our vitro two encode chalcone synthases (CPKS1 CPKS2), encodes novel type (CPKS5). show that CPKS5 kinetically favours butyryl-CoA as starter-CoA Our results suggest responsible for initiation coniine catalysing synthesis carbon backbone malonyl-CoAs.