한국미생물생명공학회:학술대회논문집 (Proceedings of the Korean Society for Applied Microbiology Conference)
- 한국미생물생명공학회 2002년도 학술발표대회
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- Pages.18-25
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- 2002
Genenation of structural diversity in polyketides by combinatorial biosynthesis of polyketides: Part I. Generation of multiple bioactive macrolides by hybrid modular polyketide synthases in Streptomyces venezuelae, Part II. Production of novel rifamycins by combinatorial biosynthesis
- Yoon, Yeo-Joon (School of Chemical Engineering and Bioengineering, University of Ulsan)
- 발행 : 2002.10.26
초록
The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and
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