Octaketide synthase

Aloe (Aloe arborescens) is a medicinal plant rich in aromatic polyketides such as pharmaceutically important aloenin (a hexaketide pyrone), aloesin (a heptaketide chromone), and barbaloin (an octaketide anthrone) (Fig. 4a). Pentaketide chromone synthase (PCS) and octaketide synthase (OKS) are novel plant-specific type III PKSs, which were obtained from the aloe plant by RT-PCR cloning using degenerate oligonucleotide primers based on the conserved sequences of known CHS enzymes [30-33]. The deduced amino acid sequences of PCS and OKS are 91% identical (368/403), and show 50-60% identity to those of other CHS superfamily type III PKSs of plant origin OKS shares 60% identity (240/403) with CHS from... 

Abe I, Oguro S, Utsumi Y, Sano Y, Noguchi H (2005) Engineered biosynthesis of plant polyketides chain length control in an octaketide-producing plant Type III polyketide synthase. J Am Chem Soc 127 12709-12716... 

Karppinen K, Hokkanen J, Manila S, Neubauer P, Hohtola A (2008) Octaketide-producing type III polyketide synthase from Hypericum perforatum is expressed in dark glands accumulating hypericins. FEBS J 275 4329-4342... 

Morita H, Kondo S, Kato R, Wanibuchi K, Noguchi H, Sugio S, Abe I, Kohno T (2007) Crystallization and preliminary crystallographic analysis of an octaketide-producing plant type III polyketide synthase. Acta Crystallograph Sect F Struct Biol Cryst Commun 63 947-949... 

Figure 2 The hybrid antibiotics 7a, 7b, and 9b made from octaketide 6, the precursor of acti-norhodin 11). or decaketide 8, the precursor of 9a, by introducing the art polyketide synthase genes into different strepiomycetes.

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