Nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) have been exploited successfully in combinatorial biosynthesis of """"""""unnatural"""""""" natural products for drug lead discovery and optimization. Hybrid NRPS-PKS systems will allow the production of novel metabolites by incorporating both amino acids and carboxylic acids, greatly expanding the size and structural diversity of resulting combinatorial biosynthetic libraries. A great challenge in constructing hybrid NRPS-PKS systems lies in the revelation of the molecular basis for intermodular communication between NRPS and PKS. I propose to continue a study of the biochemistry and genetics of the production of the bleomycins (BLMs) and related metabolites as a model for hybrid peptide-polyketide natural product biosynthesis. My long-term goal is to construct hybrid NRPS-PKS systems to produce novel cell-permeable bioactive molecules and pharmacological leads. My short-term goals for this project are (1) to biochemically and genetically characterize the BLM biosynthetic pathway and (2) to make novel BLM congeners through combinatorial biosynthesis for the discovery and development of clinically useful anticancer drugs. My hypotheses are: (1) the BLM megasynthetase is a """"""""natural"""""""" hybrid NRPS-PKS system, the studies of which will reveal how nature integrates NRPS and PKS proteins into a hybrid NRPS-PKS system; (2) the initiation and termination of BLM biosynthesis and the formation of the bithiazole moiety of BLM are unprecedented in peptide biosynthesis, the characterization of which will uncover novel chemistry for NRPSs; (3) the BLM megasynthetase provides a novel platform for combinatorial biosynthesis to make clinically valuable anticancer drugs.
My specific aims are: (1) functional analysis of the BLM biosynthetic gene cluster in vivo; (2) biochemical characterization of the BLM megasynthetase in vitro; (3) production of novel BLMs by engineering BLM biosynthesis and evaluation of them as anticancer drugs. The outcomes of these studies will (1) expand the repertoire of NRPS and PKS genes for combinatorial biosynthesis, (2) lay the foundation for rational construction of hybrid NRPS-PKS systems, and (3) potentially lead to the )roduction of novel BLMs with improved therapeutic efficacy as anticancer drugs.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-SSS-B (01))
Program Officer
Fu, Yali
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Wisconsin Madison
Schools of Pharmacy
United States
Zip Code
Chen, Jon K; Yang, Dong; Shen, Ben et al. (2016) Zorbamycin has a different DNA sequence selectivity compared with bleomycin and analogues. Bioorg Med Chem 24:6094-6101
Rudolf, Jeffrey D; Bigelow, Lance; Chang, Changsoo et al. (2015) Crystal Structure of the Zorbamycin-Binding Protein ZbmA, the Primary Self-Resistance Element in Streptomyces flavoviridis ATCC21892. Biochemistry 54:6842-51
Coughlin, Jane M; Rudolf, Jeffrey D; Wendt-Pienkowski, Evelyn et al. (2014) BlmB and TlmB provide resistance to the bleomycin family of antitumor antibiotics by N-acetylating metal-free bleomycin, tallysomycin, phleomycin, and zorbamycin. Biochemistry 53:6901-9
Huang, Sheng-Xiong; Feng, Zhiyang; Wang, Liyan et al. (2012) A designer bleomycin with significantly improved DNA cleavage activity. J Am Chem Soc 134:13501-9
Galm, Ute; Wendt-Pienkowski, Evelyn; Wang, Liyan et al. (2011) Comparative analysis of the biosynthetic gene clusters and pathways for three structurally related antitumor antibiotics: bleomycin, tallysomycin, and zorbamycin. J Nat Prod 74:526-36
Zhang, Qi; Li, Yuxue; Chen, Dandan et al. (2011) Radical-mediated enzymatic carbon chain fragmentation-recombination. Nat Chem Biol 7:154-60
Yu, Yi; Guo, Heng; Zhang, Qi et al. (2010) NosA catalyzing carboxyl-terminal amide formation in nosiheptide maturation via an enamine dealkylation on the serine-extended precursor peptide. J Am Chem Soc 132:16324-6
Tao, Meifeng; Wang, Liyan; Wendt-Pienkowski, Evelyn et al. (2010) Functional characterization of tlmH in Streptoalloteichus hindustanus E465-94 ATCC 31158 unveiling new insight into tallysomycin biosynthesis and affording a novel bleomycin analog. Mol Biosyst 6:349-56
Yu, Yi; Duan, Lian; Zhang, Qi et al. (2009) Nosiheptide biosynthesis featuring a unique indole side ring formation on the characteristic thiopeptide framework. ACS Chem Biol 4:855-64
Galm, Ute; Wendt-Pienkowski, Evelyn; Wang, Liyan et al. (2009) The biosynthetic gene cluster of zorbamycin, a member of the bleomycin family of antitumor antibiotics, from Streptomyces flavoviridis ATCC 21892. Mol Biosyst 5:77-90

Showing the most recent 10 out of 22 publications