A novel type of polyketide synthase from Saccharopolyspora erythraea

2016 Fiscal Year Final Research Report

• Project/Area Number: 26660097
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Bioorganic chemistry
• Research Institution: University of Shizuoka
• Principal Investigator: Funa Nobutaka 静岡県立大学, 食品栄養科学部, 准教授 (70361574)
• Research Collaborator: AMANO Yukako
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ポリケタイド / 放線菌

Outline of Final Research Achievements

A homolog of FabF/B, which is encoded on the genome of the actinomycetes Saccharopolyspora erythraea, was expressed in Streptomyces coelicolor M1146.　An HPLC analysis of the supernatant of the culture medium resulted in the detection of several peaks. The compounds were characterized as 6-alkyl-4-hydroxy-3-methyl-2-pyrones by NMR and MS analyses.
6-alkyl-4-hydroxy-3-methyl-2-pyrones were assumed to be assembled from acyl carrier protein (ACP) ester of β-keto acid and methylmalonyl-CoA in vivo. Therefore, we prepared N-acetylcysteamine (NAC), an analogue for ACP, ester of oxooctanoic acid (3-oxo-C8-NAC). The in vitro reaction of the homologs of FabF/B using 3-oxo-C8-NAC and methylmalonyl-CoA as substrates resulted in the synthesis of 4-hydroxy-3-methyl-6-pentyl-2-pyrone. This is the first demonstration that the single FabF/B homolog synthesized a polyketide in vitro. Thus, we propose that the enzyme system is a novel type of PKS, which we named “type IV” PKS.

Free Research Field

応用微生物学