2005 Fiscal Year Final Research Report Summary
Structure Function Analysis of Plant Type III Polyketide Synthases
| Project/Area Number |
16510164
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Living organism molecular science
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| Research Institution | University of Shizuoka |
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Principal Investigator |
ABE Ikuro University of Shizuoka, School of Pharmaceutical Sciences, Lecturer, 薬学部, 講師 (40305496)
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| Project Period (FY) |
2004 – 2005
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| Keywords | plant polyketide synthase / chalcone synthase / type III polyketide synthase / structure-function analysis / protein engineering / secondary metabolism / biologically active compounds / unnatural natural products |
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| Research Abstract |
A growing number of functionally divergent type III polyketide synthases (PKSs), the chalcone synthase (CHS) superfamily enzymes, have been cloned and characterized. In this study, we succeeded in molecular cloning and characterization of novel type III PKSs, pentaketide chromone synthase (PCS) and octaketide synthase (OKS) from aloe (Aloe arborescens). Recombinant PCS expressed in Escherichia coli catalyzed successive condensations of malonyl-CoA to produce a pentaketide, 5,7-dihydroxy-2-methylchromone, while recombinant OKS yielded octaketides, SEK4 and SEK4b, the longest polyketides produced by the structurally simple type III PKS. PCS and OKS share 92% amino acid sequence identity, and maintain the conserved Cys-His-Asn catalytic triad. The most characteristic feature is that the CHS active site residue 197 (numbering in Medicago sativa CHS) is uniquely replaced with Met in PCS and Gly in OKS, respectively. Site-directed mutagenesis revealed that the chemically inert single residue 197 lining the active-site cavity determines the polyketide chain length and the product specificity depending on the size of the side chain.
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Research Products
(24 results)
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[Journal Article] Lanosterol Synthase Mutations Cause Cholesterol Deficiency-Associated Cataracts in the Shumiya Cataract Rat2006
Author(s)
M.Mori^*, G.Li, I.Abe, J.Nakayama, Z.Guo, J.Sawashita, T.Ugawa, S.Nishizono, T.Serikawa, K.Higuchi, S.Shyumiya
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Journal Title
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Lanosterol Synthase Mutations Cause Cholesterol Deficiency-Associated Cataracts in the Shumiya Cataract Rat.2006
Author(s)
M.Mori*, G.Li, I.Abe, J.Nakayama, Z.Guo, J.Sawashita, T.Ugawa, S.Nishizono, T.Serikawa, K.Higuchi, S.Shyumiya
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Journal Title
J.Clin.Invest. (in press). WEB published on January 26
Description
「研究成果報告書概要(欧文)」より
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