title: Structure-based engineering of a plant type III polyketide synthase: formation of an unnatural nonaketide naphthopyrone.
abstract: Pentaketide chromone synthase (PCS) from Aloe arborescens is a novel plant-specific type III polyketide synthase (PKS) that produces 5,7-dihydroxy-2-methylchromone from five molecules of malonyl-CoA. On the basis of the crystal structures of wild-type and M207G mutant PCS, the F80A/Y82A/M207G triple mutant was constructed and shown to produce an unnatural novel nonaketide naphthopyrone by sequential condensations of nine molecules of malonyl-CoA. This is the first demonstration of the formation of a nonaketide by the structurally simple type III PKS. A homology model predicted that the active-site cavity volume of the triple mutant is increased to 4 times that of the wild-type PCS.
authors: School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan. abei@ys7.u-shizuoka-ken.ac.jp
authors: Ikuro
authors: I
authors: Abe
authors: Hiroyuki
authors: H
authors: Morita
authors: Satoshi
authors: S
authors: Oguro
authors: Hisashi
authors: H
authors: Noma
authors: Kiyofumi
authors: K
authors: Wanibuchi
authors: Nobuo
authors: N
authors: Kawahara
authors: Yukihiro
authors: Y
authors: Goda
authors: Hiroshi
authors: H
authors: Noguchi
authors: Toshiyuki
authors: T
authors: Kohno
mesh_terms: D000504:Aloe / Q000201:enzymology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D048630:Polyketide Synthases / Q000737:chemistry* / Q000235:genetics; D015202:Protein Engineering; D011753:Pyrones / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D011753:Pyrones; D048630:Polyketide Synthases