1
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Zhao C, Slocum ST, Sherman DH, Ruotolo BT. Time-Resolved Ion Mobility-Mass Spectrometry Reveals Structural Transitions in the Disassembly of Modular Polyketide Syntheses. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024. [PMID: 39038158 DOI: 10.1021/jasms.4c00181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
The type 1 polyketide synthase (PKS) assembly line uses its modular structure to produce polyketide natural products that form the basis of many pharmaceuticals. Currently, several cryoelectron microscopy (cryo-EM) structures of a multidomain PKS module have been constructed, but much remains to be learned. Here we utilize ion-mobility mass spectrometry (IM-MS) to record size and shape information and detect different conformational states of a 207 kDa didomain dimer comprised of ketosynthase (KS) and acyl transferase (AT), excised from full-length module. Furthermore, gas-phase stability differences between these different conformations are captured by collision induced unfolding (CIU) technology. Additionally, through tracking these forms as a function of time, we elucidate a detailed disassembly pathway for KS-AT dimers for the first time.
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Affiliation(s)
- Chunyi Zhao
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Samuel T Slocum
- Life Science Institute, Departments of Medicinal Chemistry, Chemistry and Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - David H Sherman
- Life Science Institute, Departments of Medicinal Chemistry, Chemistry and Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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2
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McCullough TM, Choudhary V, Akey DL, Skiba MA, Bernard SM, Kittendorf JD, Schmidt JJ, Sherman DH, Smith JL. Substrate Trapping in Polyketide Synthase Thioesterase Domains: Structural Basis for Macrolactone Formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599880. [PMID: 38948807 PMCID: PMC11213023 DOI: 10.1101/2024.06.20.599880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Emerging antibiotic resistance requires continual improvement in the arsenal of antimicrobial drugs, especially the critical macrolide antibiotics. Formation of the macrolactone scaffold of these polyketide natural products is catalyzed by a modular polyketide synthase (PKS) thioesterase (TE). The TE accepts a linear polyketide substrate from the termina PKS acyl carrier protein to generate an acyl-enzyme adduct that is resolved by attack of a substrate hydroxyl group to form the macrolactone. Our limited mechanistic understanding of TE selectivity for a substrate nucleophile and/or water has hampered development of TEs as biocatalysts that accommodate a variety of natural and non-natural substrates. To understand how TEs direct the substrate nucleophile for macrolactone formation, acyl-enzyme intermediates were trapped as stable amides by substituting the natural serine OH with an amino group. Incorporation of the unnatural amino acid, 1,3-diaminopropionic acid (DAP), was tested with five PKS TEs. DAP-modified TEs (TE DAP ) from the pikromycin and erythromycin pathways were purified and tested with six full-length polyketide intermediates from three pathways. The erythromycin TE had permissive substrate selectivity, whereas the pikromycin TE was selective for its native hexaketide and heptaketide substrates. In a crystal structure of a native substrate trapped in pikromycin TE DAP , the linear heptaketide was curled in the active site with the nucleophilic hydroxyl group positioned 4 Å from the amide-enzyme linkage. The curled heptaketide displayed remarkable shape complementarity with the TE acyl cavity. The strikingly different shapes of acyl cavities in TEs of known structure, including those reported here for juvenimicin, tylosin and fluvirucin biosynthesis, provide new insights to facilitate TE engineering and optimization.
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3
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Paquette AR, Brazeau-Henrie JT, Boddy CN. Thioesterases as tools for chemoenzymatic synthesis of macrolactones. Chem Commun (Camb) 2024; 60:3379-3388. [PMID: 38456624 DOI: 10.1039/d4cc00401a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Macrocycles are a key functional group that can impart unique properties into molecules. Their synthesis has led to the development of many outstanding chemical methodologies and yet still remains challenging. Thioesterase (TE) domains are frequently responsible for macrocyclization in natural product biosynthesis and provide unique strengths for the enzymatic synthesis of macrocycles. In this feature article, we describe our work to characterize the substrate selectivity of TEs and to use these enzymes as biocatalysts. Our efforts have shown that the linear thioester activated substrates are loaded on TEs with limited substrate selectivity to generate acyl-enzyme intermediates. We show that cyclization of the acyl-enzyme intermediates can be highly selective, with competing hydrolysis of the acyl-enzyme intermediates. The mechanisms controlling TE-mediated macrocyclization versus hydrolysis are a significant unsolved problem in TE biochemistry. The potential of TEs as biocatalysts was demonstrated by using them in the chemoenzymatic total synthesis of macrocyclic depsipeptide natural products. This article highlights the strengths and potential of TEs as biocatalysts as well as their limitations, opening exciting research opportunities including TE engineering to optimize these powerful biocatalysts.
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Affiliation(s)
- André R Paquette
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada K1N 6N5.
| | - Jordan T Brazeau-Henrie
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada K1N 6N5.
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada K1N 6N5.
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4
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Wang J, Deng Z, Liang J, Wang Z. Structural enzymology of iterative type I polyketide synthases: various routes to catalytic programming. Nat Prod Rep 2023; 40:1498-1520. [PMID: 37581222 DOI: 10.1039/d3np00015j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
Time span of literature covered: up to mid-2023Iterative type I polyketide synthases (iPKSs) are outstanding natural chemists: megaenzymes that repeatedly utilize their catalytic domains to synthesize complex natural products with diverse bioactivities. Perhaps the most fascinating but least understood question about type I iPKSs is how they perform the iterative yet programmed reactions in which the usage of domain combinations varies during the synthetic cycle. The programmed patterns are fulfilled by multiple factors, and strongly influence the complexity of the resulting natural products. This article reviews selected reports on the structural enzymology of iPKSs, focusing on the individual domain structures followed by highlighting the representative programming activities that each domain may contribute.
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Affiliation(s)
- Jialiang Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science & Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science & Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Jingdan Liang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science & Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Zhijun Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science & Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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5
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Jiang C, Zhou Y, Tao W, Ji S, Mao Y, Shi T, Zheng J, Bai L, Zhao YL. Theoretical Studies of Mutual Effects between 6-m-r Hemiketalization and 26-m-r Lactonization in Pimaricin Thioesterase. Chem Asian J 2023; 18:e202201229. [PMID: 36755200 DOI: 10.1002/asia.202201229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/04/2023] [Accepted: 02/05/2023] [Indexed: 02/10/2023]
Abstract
Pimaricin is a small polyene macrolide antibiotic and has been broadly used as an antimycotic and antiprotozoal agent in both humans and foods. As a thioesterase in type-I polyketide synthase, pimTE controls the 26-m-r macrolide main chain release in pimaricin biosynthesis. In this work, we sought to determine whether the 6-m-r hemiketal formation was linked to pimTE-catalyzed 26-m-r lactonization. Compared to non-hemiketal TEs, pimTE is characterized by an aspartic acid residue (D179) accessible to the U-turn motif in the acyl-enzyme intermediate. Both the covalent docking and molecular dynamics simulations demonstrate that the reactive conformations for macrocyclic lactonization are drastically promoted by the 6-m-r hemiketal. Moreover, the small-model quantum mechanistic calculations suggest that protic residues can significantly accelerate the 6-m-r hemiketal cyclization. In addition, the post-hemiketal molecular dynamic simulations demonstrate that hydrogen-bonding networks surrounding the substrate U-turn of the hairpin-shaped conformation changes significantly when the 6-m-r hemiketal is formed. In particular, the R-hemiketal intermediate is not only catalyzed by the D179 residue, but also twists the hairpin structure to the 26-m-r lactonizing pre-reaction state. By contrast, the S-hemiketal formation is unlikely catalyzed by D179, which twists the hairpin in an opposite direction. Our results propose that pimTE could be a bi-functional enzyme, which can synergistically catalyze tandem 6-m-r and 26-m-r formations during the main-chain release of pimaricin biosynthesis.
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Affiliation(s)
- Chuchu Jiang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.,Shanghai Artificial Intelligence Laboratory, Shanghai, 200232, P. R. China
| | - Yucong Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Wentao Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Shunjia Ji
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Yong Mao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Ting Shi
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Jianting Zheng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Yi-Lei Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
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6
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Brazeau-Henrie JT, Paquette AR, Boddy CN. In Vitro Biochemical Characterization of Excised Macrocyclizing Thioesterase Domains from Non-ribosomal Peptide Synthetases. Methods Mol Biol 2023; 2670:101-125. [PMID: 37184701 DOI: 10.1007/978-1-0716-3214-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Characterization of thioesterases (TEs) is an important step in understanding natural product biosynthesis. Studying non-ribosomal peptide synthetase (NRPS) TEs presents a unique set of challenges with specific cloning and expression issues as well as the challenging synthesis of the thioester peptides substrate required for characterization of the TE. In this method, we describe the cloning and expression of NRPS TEs, the synthesis of thioester peptides, and the in vitro biochemical characterization of the enzyme.
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Affiliation(s)
| | - André R Paquette
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada.
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7
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Fraley AE, Dieterich CL, Mabesoone MFJ, Minas HA, Meoded RA, Hemmerling F, Piel J. Structure of a Promiscuous Thioesterase Domain Responsible for Branching Acylation in Polyketide Biosynthesis. Angew Chem Int Ed Engl 2022; 61:e202206385. [DOI: 10.1002/anie.202206385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Amy E. Fraley
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Cora L. Dieterich
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Mathijs F. J. Mabesoone
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Hannah A. Minas
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Roy A Meoded
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Franziska Hemmerling
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
| | - Jörn Piel
- Department of Biology, Institute of Microbiology Eidgenössische Technische Hochschule (ETH) Zurich Vladimir-Prelog-Weg 4 8093 Zurich Switzerland
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8
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Fraley AE, Dieterich C, Mabesoone M, Minas HA, Meoded RA, Hemmerling F, Piel J. Structure of a promiscuous thioesterase domain responsible for branching acylation in polyketide biosynthesis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Amy E. Fraley
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Cora Dieterich
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Mathijs Mabesoone
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Hannah A. Minas
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Roy A. Meoded
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Franziska Hemmerling
- Eidgenossische Technische Hochschule Zurich Institute of Microbiology SWITZERLAND
| | - Jörn Piel
- ETH Zürich Department of Biology Vladimir-Prelog-Weg 4 8093 Zürich SWITZERLAND
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9
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Caswell BT, de Carvalho CC, Nguyen H, Roy M, Nguyen T, Cantu DC. Thioesterase enzyme families: Functions, structures, and mechanisms. Protein Sci 2022; 31:652-676. [PMID: 34921469 PMCID: PMC8862431 DOI: 10.1002/pro.4263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Thioesterases are enzymes that hydrolyze thioester bonds in numerous biochemical pathways, for example in fatty acid synthesis. This work reports known functions, structures, and mechanisms of updated thioesterase enzyme families, which are classified into 35 families based on sequence similarity. Each thioesterase family is based on at least one experimentally characterized enzyme, and most families have enzymes that have been crystallized and their tertiary structure resolved. Classifying thioesterases into families allows to predict tertiary structures and infer catalytic residues and mechanisms of all sequences in a family, which is particularly useful because the majority of known protein sequence have no experimental characterization. Phylogenetic analysis of experimentally characterized thioesterases that have structures with the two main structural folds reveal convergent and divergent evolution. Based on tertiary structure superimposition, catalytic residues are predicted.
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Affiliation(s)
- Benjamin T. Caswell
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Caio C. de Carvalho
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Hung Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Monikrishna Roy
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Tin Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - David C. Cantu
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
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10
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Zhou Y, Tao W, Qi Z, Wei J, Shi T, Kang Q, Zheng J, Zhao Y, Bai L. Structural and Mechanistic Insights into Chain Release of the Polyene PKS Thioesterase Domain. ACS Catal 2021. [DOI: 10.1021/acscatal.1c04991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yucong Zhou
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wentao Tao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhen Qi
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jianhua Wei
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ting Shi
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qianjin Kang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jianting Zheng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yilei Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
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11
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Drufva EE, Hix EG, Bailey CB. Site directed mutagenesis as a precision tool to enable synthetic biology with engineered modular polyketide synthases. Synth Syst Biotechnol 2020; 5:62-80. [PMID: 32637664 PMCID: PMC7327777 DOI: 10.1016/j.synbio.2020.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/01/2020] [Accepted: 04/06/2020] [Indexed: 12/04/2022] Open
Abstract
Modular polyketide synthases (PKSs) are a multidomain megasynthase class of biosynthetic enzymes that have great promise for the development of new compounds, from new pharmaceuticals to high value commodity and specialty chemicals. Their colinear biosynthetic logic has been viewed as a promising platform for synthetic biology for decades. Due to this colinearity, domain swapping has long been used as a strategy to introduce molecular diversity. However, domain swapping often fails because it perturbs critical protein-protein interactions within the PKS. With our increased level of structural elucidation of PKSs, using judicious targeted mutations of individual residues is a more precise way to introduce molecular diversity with less potential for global disruption of the protein architecture. Here we review examples of targeted point mutagenesis to one or a few residues harbored within the PKS that alter domain specificity or selectivity, affect protein stability and interdomain communication, and promote more complex catalytic reactivity.
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Key Words
- ACP, acyl carrier protein
- AT, acyltransferase
- DEBS, 6-deoxyerthronolide B synthase
- DH, dehydratase
- EI, enoylisomerase
- ER, enoylreductase
- KR, ketoreductase
- KS, ketosynthase
- LM, loading module
- MT, methyltransferase
- Mod, module
- PKS, polyketide synthase
- PS, pyran synthase
- Polyketide synthase
- Protein engineering
- Rational design
- SNAC, N-acetyl cysteamine
- Saturation mutagenesis
- Site directed mutagenesis
- Synthetic biology
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Affiliation(s)
- Erin E. Drufva
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA
| | - Elijah G. Hix
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA
| | - Constance B. Bailey
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA
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12
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Blake-Hedges JM, Pereira JH, Cruz-Morales P, Thompson MG, Barajas JF, Chen J, Krishna RN, Chan LJG, Nimlos D, Alonso-Martinez C, Baidoo EEK, Chen Y, Gin JW, Katz L, Petzold CJ, Adams PD, Keasling JD. Structural Mechanism of Regioselectivity in an Unusual Bacterial Acyl-CoA Dehydrogenase. J Am Chem Soc 2020; 142:835-846. [PMID: 31793780 DOI: 10.1021/jacs.9b09187] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Terminal alkenes are easily derivatized, making them desirable functional group targets for polyketide synthase (PKS) engineering. However, they are rarely encountered in natural PKS systems. One mechanism for terminal alkene formation in PKSs is through the activity of an acyl-CoA dehydrogenase (ACAD). Herein, we use biochemical and structural analysis to understand the mechanism of terminal alkene formation catalyzed by an γ,δ-ACAD from the biosynthesis of the polyketide natural product FK506, TcsD. While TcsD is homologous to canonical α,β-ACADs, it acts regioselectively at the γ,δ-position and only on α,β-unsaturated substrates. Furthermore, this regioselectivity is controlled by a combination of bulky residues in the active site and a lateral shift in the positioning of the FAD cofactor within the enzyme. Substrate modeling suggests that TcsD utilizes a novel set of hydrogen bond donors for substrate activation and positioning, preventing dehydrogenation at the α,β position of substrates. From the structural and biochemical characterization of TcsD, key residues that contribute to regioselectivity and are unique to the protein family were determined and used to identify other putative γ,δ-ACADs that belong to diverse natural product biosynthetic gene clusters. These predictions are supported by the demonstration that a phylogenetically distant homologue of TcsD also regioselectively oxidizes α,β-unsaturated substrates. This work exemplifies a powerful approach to understand unique enzymatic reactions and will facilitate future enzyme discovery, inform enzyme engineering, and aid natural product characterization efforts.
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Affiliation(s)
- Jacquelyn M Blake-Hedges
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Jose Henrique Pereira
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Mitchell G Thompson
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Plant and Microbial Biology , University of California-Berkeley , Berkeley , California 94720 , United States
| | - Jesus F Barajas
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Plant and Microbial Biology , University of California-Berkeley , Berkeley , California 94720 , United States
| | - Jeffrey Chen
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Rohith N Krishna
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Leanne Jade G Chan
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Danika Nimlos
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Catalina Alonso-Martinez
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Edward E K Baidoo
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Yan Chen
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Energy Agile BioFoundry , Emeryville , California 94608 , United States
| | - Jennifer W Gin
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Energy Agile BioFoundry , Emeryville , California 94608 , United States
| | - Leonard Katz
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,QB3 Institute , University of California-Berkeley , Emeryville , California 94608 , United States
| | - Christopher J Petzold
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Energy Agile BioFoundry , Emeryville , California 94608 , United States
| | - Paul D Adams
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Jay D Keasling
- Joint BioEnergy Institute , Emeryville , California 94608 , United States.,Biological Systems and Engineering Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,QB3 Institute , University of California-Berkeley , Emeryville , California 94608 , United States.,Department of Chemical & Biomolecular Engineering, Department of Bioengineering , University of California-Berkeley , Berkeley , California 94720 , United States.,Novo Nordisk Foundation Center for Biosustainability , Technical University Denmark , DK2970 Horsholm , Denmark.,Center for Synthetic Biochemistry , Shenzhen Institutes for Advanced Technologies , Shenzhen 518055 , P. R. China
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13
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Kornfuehrer T, Eustáquio AS. Diversification of polyketide structures via synthase engineering. MEDCHEMCOMM 2019; 10:1256-1272. [PMID: 32180918 PMCID: PMC7053703 DOI: 10.1039/c9md00141g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/09/2019] [Indexed: 12/16/2022]
Abstract
Polyketide natural products possess diverse biological activities including antibiotic, anticancer, and immunosuppressive. Their equally varied and complex structures arise from head-to-tail condensation of simple carboxyacyl monomers. Since the seminal discovery that biosynthesis of polyketides such as the macrolide erythromycin is catalyzed by uncharacteristically large, multifunctional enzymes, termed modular type I polyketide synthases, chemists and biologists alike have been inspired to harness the apparent modularity of the synthases to further diversify polyketide structures. Yet, initial attempts to perform "combinatorial biosynthesis" failed due to challenges associated with maintaining the structural and catalytic integrity of large, chimeric synthases. Fast forward nearly 30 years, and advancements in our understanding of polyketide synthase structure and function have allowed the field to make significant progress toward effecting desired modifications to polyketide scaffolds in addition to engineering small, chiral fragments. This review highlights selected examples of polyketide diversification via control of monomer selection, oxidation state, stereochemistry, and cyclization. We conclude with a perspective on the present and future of polyketide structure diversification and hope that the examples presented here will encourage medicinal chemists to embrace polyketide synthetic biology as a means to revitalize polyketide drug discovery.
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Affiliation(s)
- Taylor Kornfuehrer
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences , College of Pharmacy , University of Illinois at Chicago , Chicago , Illinois 60607 , USA . ; Tel: +1 3124137082
| | - Alessandra S Eustáquio
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences , College of Pharmacy , University of Illinois at Chicago , Chicago , Illinois 60607 , USA . ; Tel: +1 3124137082
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14
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Chen H, Bian Z, Ravichandran V, Li R, Sun Y, Huo L, Fu J, Bian X, Xia L, Tu Q, Zhang Y. Biosynthesis of polyketides by trans-AT polyketide synthases in Burkholderiales. Crit Rev Microbiol 2019; 45:162-181. [PMID: 31218924 DOI: 10.1080/1040841x.2018.1514365] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Widely used as drugs and agrochemicals, polyketides are a family of bioactive natural products, with diverse structures and functions. Polyketides are produced by megaenzymes termed as polyketide synthases (PKSs). PKS biosynthetic pathways are divided into the cis-AT PKSs and trans-AT PKSs; a division based mainly on the absence of an acyltransferase (AT) domain in the trans-AT PKS modules. In trans-AT biosynthesis, the AT activity is contributed via one or several independent proteins, and there are few other characteristics that distinguish trans-AT PKSs from cis-AT PKSs, especially in the formation of the β-branch. The trans-AT PKSs constitute a major PKS pathway, and many are found in Burkholderia species, which are prevalent in the environment and prolific sources of polyketides. This review summarizes studies from 1973 to 2017 on the biosynthesis of natural products by trans-AT PKSs from Burkholderia species.
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Affiliation(s)
- Hanna Chen
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China.,b State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science , Hunan Normal University , Changsha , People's Republic of China
| | - Zhilong Bian
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Vinothkannan Ravichandran
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Ruijuan Li
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Yi Sun
- c Institute of Chinese Materia Medica , China Academy of Chinese Medical Sciences , Beijing , People's Republic of China
| | - Liujie Huo
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Jun Fu
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Xiaoying Bian
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Liqiu Xia
- b State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science , Hunan Normal University , Changsha , People's Republic of China
| | - Qiang Tu
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China
| | - Youming Zhang
- a Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences , Shandong University , Qingdao , People's Republic of China.,b State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science , Hunan Normal University , Changsha , People's Republic of China
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15
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Trapping biosynthetic acyl-enzyme intermediates with encoded 2,3-diaminopropionic acid. Nature 2018; 565:112-117. [PMID: 30542153 DOI: 10.1038/s41586-018-0781-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/02/2018] [Indexed: 11/08/2022]
Abstract
Many enzymes catalyse reactions that proceed through covalent acyl-enzyme (ester or thioester) intermediates1. These enzymes include serine hydrolases2,3 (encoded by one per cent of human genes, and including serine proteases and thioesterases), cysteine proteases (including caspases), and many components of the ubiquitination machinery4,5. Their important acyl-enzyme intermediates are unstable, commonly having half-lives of minutes to hours6. In some cases, acyl-enzyme complexes can be stabilized using substrate analogues or active-site mutations but, although these approaches can provide valuable insight7-10, they often result in complexes that are substantially non-native. Here we develop a strategy for incorporating 2,3-diaminopropionic acid (DAP) into recombinant proteins, via expansion of the genetic code11. We show that replacing catalytic cysteine or serine residues of enzymes with DAP permits their first-step reaction with native substrates, allowing the efficient capture of acyl-enzyme complexes that are linked through a stable amide bond. For one of these enzymes, the thioesterase domain of valinomycin synthetase12, we elucidate the biosynthetic pathway by which it progressively oligomerizes tetradepsipeptidyl substrates to a dodecadepsipeptidyl intermediate, which it then cyclizes to produce valinomycin. By trapping the first and last acyl-thioesterase intermediates in the catalytic cycle as DAP conjugates, we provide structural insight into how conformational changes in thioesterase domains of such nonribosomal peptide synthetases control the oligomerization and cyclization of linear substrates. The encoding of DAP will facilitate the characterization of diverse acyl-enzyme complexes, and may be extended to capturing the native substrates of transiently acylated proteins of unknown function.
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16
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Park JW, Yoon YJ. Recent advances in the discovery and combinatorial biosynthesis of microbial 14-membered macrolides and macrolactones. J Ind Microbiol Biotechnol 2018; 46:445-458. [PMID: 30415291 DOI: 10.1007/s10295-018-2095-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/19/2018] [Indexed: 01/05/2023]
Abstract
Macrolides, especially 14-membered macrolides, are a valuable group of antibiotics that originate from various microorganisms. In addition to their antibacterial activity, newly discovered 14-membered macrolides exhibit other therapeutic potentials, such as anti-proliferative and anti-protistal activities. Combinatorial biosynthetic approaches will allow us to create structurally diversified macrolide analogs, which are especially important during the emerging post-antibiotic era. This review focuses on recent advances in the discovery of new 14-membered macrolides (also including macrolactones) from microorganisms and the current status of combinatorial biosynthetic approaches, including polyketide synthase (PKS) and post-PKS tailoring pathways, and metabolic engineering for improved production together with heterologous production of 14-membered macrolides.
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Affiliation(s)
- Je Won Park
- School of Biosystem and Biomedical Science, Korea University, Seoul, 02841, Republic of Korea
| | - Yeo Joon Yoon
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, 03760, Republic of Korea.
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17
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Dodge GJ, Maloney FP, Smith JL. Protein-protein interactions in "cis-AT" polyketide synthases. Nat Prod Rep 2018; 35:1082-1096. [PMID: 30188553 PMCID: PMC6207950 DOI: 10.1039/c8np00058a] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to the end of 2018 Polyketides are a valuable source of bioactive and clinically important molecules. The biosynthesis of these chemically complex molecules has led to the discovery of equally complex polyketide synthase (PKS) pathways. Crystallography has yielded snapshots of individual catalytic domains, di-domains, and multi-domains from a variety of PKS megasynthases, and cryo-EM studies have provided initial views of a PKS module in a series of defined biochemical states. Here, we review the structural and biochemical results that shed light on the protein-protein interactions critical to catalysis by PKS systems with an embedded acyltransferase. Interactions include those that occur both within and between PKS modules, as well as with accessory enzymes.
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Affiliation(s)
- Greg J Dodge
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA 48109.
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18
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Galea CA, Roberts KD, Zhu Y, Thompson PE, Li J, Velkov T. Functional Characterization of the Unique Terminal Thioesterase Domain from Polymyxin Synthetase. Biochemistry 2017; 56:657-668. [PMID: 28071053 DOI: 10.1021/acs.biochem.6b01139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Polymyxins remain one of the few antibiotics available for treating antibiotic resistant bacteria. Here we describe polymyxin B thioesterase which performs the final step in polymyxin B biosynthesis. Isolated thioesterase catalyzed cyclization of an N-acetylcystamine polymyxin B analogue to form polymyxin B. The thioesterase contained a catalytic cysteine unlike most thioesterases which possess a serine. Supporting this, incubation of polymyxin B thioesterase with reducing agents abolished enzymatic activity, while mutation of the catalytic cysteine to serine significantly decreased activity. NMR spectroscopy demonstrated that uncyclized polymyxin B was disordered in solution, unlike other thioesterase substrates which adopt a transient structure similar to their product. Modeling showed the thioesterase substrate-binding cleft was highly negatively charged, suggesting a mechanism for the cyclization of the substrate. These studies provide new insights into the role of polymyxin thioesterase in polymyxin biosynthesis and highlight its potential use for the chemoenzymatic synthesis of polymyxin lipopeptides.
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Affiliation(s)
| | | | - Yan Zhu
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University , Parkville, Victoria 3800, Australia
| | | | - Jian Li
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University , Parkville, Victoria 3800, Australia
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19
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Robbins T, Liu YC, Cane DE, Khosla C. Structure and mechanism of assembly line polyketide synthases. Curr Opin Struct Biol 2016; 41:10-18. [PMID: 27266330 PMCID: PMC5136517 DOI: 10.1016/j.sbi.2016.05.009] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 11/16/2022]
Abstract
Assembly line polyketide synthases (PKSs) are remarkable biosynthetic machines with considerable potential for structure-based engineering. Several types of protein-protein interactions, both within and between PKS modules, play important roles in the catalytic cycle of a multimodular PKS. Additionally, vectorial biosynthesis is enabled by the energetic coupling of polyketide chain elongation to the channeling of intermediates between successive modules. A combination of high-resolution analysis of smaller PKS components and lower resolution characterization of intact modules and bimodules has yielded insights into the structure and organization of a prototypical assembly line PKS. This review discusses our understanding of key structure-function relationships in this family of megasynthases, along with a recap of key unanswered questions in the field.
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Affiliation(s)
- Thomas Robbins
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - Yu-Chen Liu
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - David E Cane
- Department of Chemistry, Brown University, Providence, RI 02912-9108, United States
| | - Chaitan Khosla
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States; Department of Chemical Engineering, Stanford University, Stanford, CA 94305, United States.
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20
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Choi SS, Nah HJ, Pyeon HR, Kim ES. Biosynthesis, regulation, and engineering of a linear polyketide tautomycetin: a novel immunosuppressant in Streptomyces sp. CK4412. J Ind Microbiol Biotechnol 2016; 44:555-561. [PMID: 27734184 DOI: 10.1007/s10295-016-1847-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 09/28/2016] [Indexed: 01/25/2023]
Abstract
Tautomycetin (TMC) is a natural product with a linear structure that includes an ester bond connecting a dialkylmaleic moiety to a type I polyketide chain. Although TMC was originally identified as an antifungal antibiotic in the late 1980s, follow-up studies revealed its novel immunosuppressant activity. Specifically, TMC exhibited a mechanistically unique immunosuppressant activity about 100 times higher than that of cyclosporine A, a widely used immunosuppressant drug. Interestingly, a structurally close relative, tautomycin (TTM), was reported to not possess TMC-like immunosuppressant activity, suggesting that a distinctive polyketide moiety of TMC plays a critical role in immunosuppressant activity. Cloning and engineering of a TMC polyketide biosynthetic gene cluster generated several derivatives showing different biological activities. TMC was also found to be biosynthesized as a linear structure without forming a lactone ring, unlike the most polyketide-based compounds, implying the presence of a unique polyketide thioesterase in the cluster. Although TMC biosynthesis was limited due to its tight regulation by two pathway-specific regulatory genes located in the cluster, its production was significantly stimulated through homologous and heterologous expression of its entire biosynthetic gene cluster using a Streptomyces artificial chromosome vector system. In this mini-review, we summarize recent advances in the biosynthesis, regulation, and pathway engineering of a linear polyketide, TMC, in Streptomyces sp. CK4412.
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Affiliation(s)
- Si-Sun Choi
- Department of Biological Engineering, Inha University, Incheon, 402-751, Korea
| | - Hee-Ju Nah
- Department of Biological Engineering, Inha University, Incheon, 402-751, Korea
| | - Hye-Rim Pyeon
- Department of Biological Engineering, Inha University, Incheon, 402-751, Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon, 402-751, Korea.
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21
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Thioesterase domain swapping of a linear polyketide tautomycetin with a macrocyclic polyketide pikromycin in Streptomyces sp. CK4412. J Ind Microbiol Biotechnol 2016; 43:1189-93. [PMID: 27277081 DOI: 10.1007/s10295-016-1790-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/25/2016] [Indexed: 10/21/2022]
Abstract
Tautomycetin (TMC) is a linear polyketide metabolite produced by Streptomyces sp. CK4412 that has been reported to possess multiple biological functions including T cell-specific immunosuppressive and anticancer activities that occur through a mechanism of differential inhibition of protein phosphatases such as PP1, PP2A, and SHP2. We previously reported the characterization of the entire TMC biosynthetic gene cluster constituted by multifunctional type I polyketide synthase (PKS) assembly and suggested that the linear form of TMC could be generated via free acid chain termination by a narrow TMC thioesterase (TE) pocket. The modular nature of the assembly presents a unique opportunity to alter or interchange the native biosynthetic domains to produce targeted variants of TMC. Herein, we report swapping of the TMC TE domain sequence with the exact counterpart of the macrocyclic polyketide pikromycin (PIK) TE. PIK TE-swapped Streptomyces sp. CK4412 mutant produced not only TMC, but also a cyclized form of TMC, implying that the bioengineering based in vivo custom construct can be exploited to produce engineered macrolactones with new structural functionality.
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22
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Zhou Y, Murphy AC, Samborskyy M, Prediger P, Dias LC, Leadlay PF. Iterative Mechanism of Macrodiolide Formation in the Anticancer Compound Conglobatin. ACTA ACUST UNITED AC 2016; 22:745-54. [PMID: 26091168 PMCID: PMC4504003 DOI: 10.1016/j.chembiol.2015.05.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/15/2015] [Accepted: 05/17/2015] [Indexed: 11/25/2022]
Abstract
Conglobatin is an unusual C2-symmetrical macrodiolide from the bacterium Streptomyces conglobatus with promising antitumor activity. Insights into the genes and enzymes that govern both the assembly-line production of the conglobatin polyketide and its dimerization are essential to allow rational alterations to be made to the conglobatin structure. We have used a rapid, direct in vitro cloning method to obtain the entire cluster on a 41-kbp fragment, encoding a modular polyketide synthase assembly line. The cloned cluster directs conglobatin biosynthesis in a heterologous host strain. Using a model substrate to mimic the conglobatin monomer, we also show that the conglobatin cyclase/thioesterase acts iteratively, ligating two monomers head-to-tail then re-binding the dimer product and cyclizing it. Incubation of two different monomers with the cyclase produces hybrid dimers and trimers, providing the first evidence that conglobatin analogs may in future become accessible through engineering of the polyketide synthase. The conglobatin cluster has been cloned using a single-step in vitro procedure The gene cluster in a heterologous strain confers the ability to produce conglobatin A model for ATP-dependent heterocyclization to the oxazole ring is proposed The conglobatin thioesterase catalyzes cyclodimerization by an iterative mechanism
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Affiliation(s)
- Yongjun Zhou
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Annabel C Murphy
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | | | - Patricia Prediger
- Faculty of Technology, State University of Campinas UNICAMP, CEP 134840332 Limeira, São Paulo, Brazil
| | - Luiz Carlos Dias
- Institute of Chemistry, State University of Campinas, UNICAMP, C.P. 6154, CEP 13084-971 Campinas, São Paulo, Brazil
| | - Peter F Leadlay
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK.
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23
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Horsman ME, Hari TPA, Boddy CN. Polyketide synthase and non-ribosomal peptide synthetase thioesterase selectivity: logic gate or a victim of fate? Nat Prod Rep 2016; 33:183-202. [DOI: 10.1039/c4np00148f] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thioesterases (TEs) are product offloading enzymes from FAS, PKS, and NRPS complexes. We review the diversity, structure, and mechanism of PKS and NRPS TEs and analyze TE loading and release steps as possible logic gates with a view to predicting TE function in new pathways.
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Affiliation(s)
- Mark E. Horsman
- Department of chemistry
- Centre for Catalysis Research and Innovation
- University of Ottawa
- Canada
| | - Taylor P. A. Hari
- Department of chemistry
- Centre for Catalysis Research and Innovation
- University of Ottawa
- Canada
| | - Christopher N. Boddy
- Department of chemistry
- Centre for Catalysis Research and Innovation
- University of Ottawa
- Canada
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24
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Tan GY, Deng Z, Liu T. Recent advances in the elucidation of enzymatic function in natural product biosynthesis. F1000Res 2015; 4. [PMID: 26989472 PMCID: PMC4784017 DOI: 10.12688/f1000research.7187.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2016] [Indexed: 01/20/2023] Open
Abstract
With the successful production of artemisinic acid in yeast, the promising potential of synthetic biology for natural product biosynthesis is now being realized. The recent total biosynthesis of opioids in microbes is considered to be another landmark in this field. The importance and significance of enzymes in natural product biosynthetic pathways have been re-emphasized by these advancements. Therefore, the characterization and elucidation of enzymatic function in natural product biosynthesis are undoubtedly fundamental for the development of new drugs and the heterologous biosynthesis of active natural products. Here, discoveries regarding enzymatic function in natural product biosynthesis over the past year are briefly reviewed.
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Affiliation(s)
- Gao-Yi Tan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan, China; Hubei Engineering Laboratory for Synthetic Microbiology, Wuhan Institute of Biotechnology, Wuhan, China
| | - Tiangang Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan, China; Hubei Engineering Laboratory for Synthetic Microbiology, Wuhan Institute of Biotechnology, Wuhan, China
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25
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The structural biology of biosynthetic megaenzymes. Nat Chem Biol 2015; 11:660-70. [PMID: 26284673 DOI: 10.1038/nchembio.1883] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/02/2015] [Indexed: 01/27/2023]
Abstract
The modular polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) are among the largest and most complicated enzymes in nature. In these biosynthetic systems, independently folding protein domains, which are organized into units called 'modules', operate in assembly-line fashion to construct polymeric chains and tailor their functionalities. Products of PKSs and NRPSs include a number of blockbuster medicines, and this has motivated researchers to understand how they operate so that they can be modified by genetic engineering. Beginning in the 1990s, structural biology has provided a number of key insights. The emerging picture is one of remarkable dynamics and conformational programming in which the chemical states of individual catalytic domains are communicated to the others, configuring the modules for the next stage in the biosynthesis. This unexpected level of complexity most likely accounts for the low success rate of empirical genetic engineering experiments and suggests ways forward for productive megaenzyme synthetic biology.
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26
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Zhou Y, Prediger P, Dias LC, Murphy AC, Leadlay PF. Macrodiolide formation by the thioesterase of a modular polyketide synthase. Angew Chem Int Ed Engl 2015; 54:5232-5. [PMID: 25753953 PMCID: PMC4471547 DOI: 10.1002/anie.201500401] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 02/04/2015] [Indexed: 11/10/2022]
Abstract
Elaiophylin is an unusual C2 -symmetric antibiotic macrodiolide produced on a bacterial modular polyketide synthase assembly line. To probe the mechanism and selectivity of diolide formation, we sought to reconstitute ring formation in vitro by using a non-natural substrate. Incubation of recombinant elaiophylin thioesterase/cyclase with a synthetic pentaketide analogue of the presumed monomeric polyketide precursor of elaiophylin, specifically its N-acetylcysteamine thioester, produced a novel 16-membered C2 -symmetric macrodiolide. A linear dimeric thioester is an intermediate in ring formation, which indicates iterative use of the thioesterase active site in ligation and subsequent cyclization. Furthermore, the elaiophylin thioesterase acts on a mixture of pentaketide and tetraketide thioesters to give both the symmetric decaketide diolide and the novel asymmetric hybrid nonaketide diolide. Such thioesterases have potential as tools for the in vitro construction of novel diolides.
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Affiliation(s)
- Yongjun Zhou
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
| | - Patrícia Prediger
- Institute of Chemistry, State University of Campinas, UNICAMPC.P. 6154, CEP 13084-971, Campinas SP (Brazil)
| | - Luiz Carlos Dias
- Institute of Chemistry, State University of Campinas, UNICAMPC.P. 6154, CEP 13084-971, Campinas SP (Brazil)
| | - Annabel C Murphy
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
| | - Peter F Leadlay
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
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27
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Zhou Y, Prediger P, Dias LC, Murphy AC, Leadlay PF. Macrodiolide Formation by the Thioesterase of a Modular Polyketide Synthase. ACTA ACUST UNITED AC 2015; 127:5321-5324. [PMID: 26300568 PMCID: PMC4535664 DOI: 10.1002/ange.201500401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 02/04/2015] [Indexed: 01/24/2023]
Abstract
Elaiophylin is an unusual C2-symmetric antibiotic macrodiolide produced on a bacterial modular polyketide synthase assembly line. To probe the mechanism and selectivity of diolide formation, we sought to reconstitute ring formation in vitro by using a non-natural substrate. Incubation of recombinant elaiophylin thioesterase/cyclase with a synthetic pentaketide analogue of the presumed monomeric polyketide precursor of elaiophylin, specifically its N-acetylcysteamine thioester, produced a novel 16-membered C2-symmetric macrodiolide. A linear dimeric thioester is an intermediate in ring formation, which indicates iterative use of the thioesterase active site in ligation and subsequent cyclization. Furthermore, the elaiophylin thioesterase acts on a mixture of pentaketide and tetraketide thioesters to give both the symmetric decaketide diolide and the novel asymmetric hybrid nonaketide diolide. Such thioesterases have potential as tools for the in vitro construction of novel diolides.
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Affiliation(s)
- Yongjun Zhou
- Department of Biochemistry, University of Cambridge 80 Tennis Court Road, Cambridge CB2 1GA (UK) E-mail:
| | - Patrícia Prediger
- Institute of Chemistry, State University of Campinas UNICAMP, C.P. 6154, CEP 13084-971, Campinas SP (Brazil)
| | - Luiz Carlos Dias
- Institute of Chemistry, State University of Campinas UNICAMP, C.P. 6154, CEP 13084-971, Campinas SP (Brazil)
| | - Annabel C Murphy
- Department of Biochemistry, University of Cambridge 80 Tennis Court Road, Cambridge CB2 1GA (UK) E-mail:
| | - Peter F Leadlay
- Department of Biochemistry, University of Cambridge 80 Tennis Court Road, Cambridge CB2 1GA (UK) E-mail:
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Obeso JI, Maestro B, Sanz JM, Olivera ER, Luengo JM. The loss of function of PhaC1 is a survival mechanism that counteracts the stress caused by the overproduction of poly-3-hydroxyalkanoates in Pseudomonas putidaΔfadBA. Environ Microbiol 2015; 17:3182-94. [PMID: 25627209 DOI: 10.1111/1462-2920.12753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 12/12/2014] [Indexed: 12/01/2022]
Abstract
The poly-3-hydroxylkanoate (PHA)-overproducing mutant Pseudomonas putida U ΔfadBA (PpΔfadBA) lacks the genes encoding the main β-oxidation pathway (FadBA). This strain accumulates enormous amounts of bioplastics when cultured in chemically defined media containing PHA precursors (different n-alkanoic or n-aryl-alkanoic acids) and an additional carbon source. In medium containing glucose or 4-hydroxy-phenylacetate, the mutant does not accumulate PHAs and grows just as the wild type (P. putida U). However, when the carbon source is octanoate, growth is severely impaired, suggesting that in PpΔfadBA, the metabolic imbalance resulting from a lower rate of β-oxidation, together with the accumulation of bioplastics, causes severe physiological stress. Here, we show that PpΔfadBA efficiently counteracts this latter effect via a survival mechanism involving the introduction of spontaneous mutations that block PHA accumulation. Surprisingly, genetic analyses of the whole pha cluster revealed that these mutations occurred only in the gene encoding one of the polymerases (phaC1) and that the loss of PhaC1 function was enough to prevent PHA synthesis. The influence of these mutations on the structure of PhaC1 and the existence of a protein-protein (PhaC1-PhaC2) interaction that explains the functionality of the polymerization system are discussed herein.
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Affiliation(s)
- José I Obeso
- Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, 24071, Spain
| | - Beatriz Maestro
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Alicante, 03202, Spain
| | - Jesús M Sanz
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Alicante, 03202, Spain
| | - Elías R Olivera
- Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, 24071, Spain
| | - José M Luengo
- Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, 24071, Spain
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29
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Gui C, Li Q, Mo X, Qin X, Ma J, Ju J. Discovery of a New Family of Dieckmann Cyclases Essential to Tetramic Acid and Pyridone-Based Natural Products Biosynthesis. Org Lett 2015; 17:628-31. [PMID: 25621700 DOI: 10.1021/ol5036497] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chun Gui
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 110039, China
| | - Qinglian Li
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Xuhua Mo
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Shandong
Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China
| | - Xiangjing Qin
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Junying Ma
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Jianhua Ju
- CAS
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong
Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology,
South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
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30
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Heberlig GW, Wirz M, Wang M, Boddy CN. Resorcylic acid lactone biosynthesis relies on a stereotolerant macrocyclizing thioesterase. Org Lett 2014; 16:5858-61. [PMID: 25372311 DOI: 10.1021/ol502747t] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Zearalenone and radicicol are highly related resorcylic acid lactones with the rare property of having opposite stereochemical configurations of the secondary alcohol involved in lactone formation. The ability of the thioesterases from the zearalenone and radicicol biosynthetic pathways to macrocyclize both D and L configured synthetic substrate analogs was biochemically characterized and showed that both enzymes were highly stereotolerant, macrocyclizing both substrates with similar kinetic parameters. This observed stereotolerance is consistent with a proposed evolution of both natural products from a common ancestral resorcylic acid lactone.
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Affiliation(s)
- Graham W Heberlig
- Department of Chemistry, Centre for Catalysis Research and Innovation, University of Ottawa , Ottawa, ON K1N 6N5, Canada
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31
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Hari TPA, Labana P, Boileau M, Boddy CN. An evolutionary model encompassing substrate specificity and reactivity of type I polyketide synthase thioesterases. Chembiochem 2014; 15:2656-61. [PMID: 25354333 DOI: 10.1002/cbic.201402475] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Indexed: 11/10/2022]
Abstract
Bacterial polyketides are a rich source of chemical diversity and pharmaceutical agents. Understanding the biochemical basis for their biosynthesis and the evolutionary driving force leading to this diversity is essential to take advantage of the enzymes as biocatalysts and to access new chemical diversity for drug discovery. Biochemical characterization of the thioesterase (TE) responsible for 6-deoxyerythronolide macrocyclization shows that a small, evolutionarily accessible change to the substrate can increase the chemical diversity of products, including macrodiolide formation. We propose an evolutionary model in which TEs are by nature non-selective for the type of chemistry they catalyze, producing a range of metabolites. As one metabolite becomes essential for improving fitness in a particular environment, the TE evolves to enrich for that corresponding reactivity. This hypothesis is supported by our phylogenetic analysis, showing convergent evolution of macrodiolide-forming TEs.
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Affiliation(s)
- Taylor P A Hari
- Departments of Chemistry and Biology, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON K1N 6N5 (Canada)
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32
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Abstract
Polyketide natural products constitute a broad class of compounds with diverse structural features and biological activities. Their biosynthetic machinery, represented by type I polyketide synthases (PKSs), has an architecture in which successive modules catalyse two-carbon linear extensions and keto-group processing reactions on intermediates covalently tethered to carrier domains. Here we used electron cryo-microscopy to determine sub-nanometre-resolution three-dimensional reconstructions of a full-length PKS module from the bacterium Streptomyces venezuelae that revealed an unexpectedly different architecture compared to the homologous dimeric mammalian fatty acid synthase. A single reaction chamber provides access to all catalytic sites for the intramodule carrier domain. In contrast, the carrier from the preceding module uses a separate entrance outside the reaction chamber to deliver the upstream polyketide intermediate for subsequent extension and modification. This study reveals for the first time, to our knowledge, the structural basis for both intramodule and intermodule substrate transfer in polyketide synthases, and establishes a new model for molecular dissection of these multifunctional enzyme systems.
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33
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McCarthy JG, Eisman EB, Kulkarni S, Gerwick L, Gerwick WH, Wipf P, Sherman DH, Smith JL. Structural basis of functional group activation by sulfotransferases in complex metabolic pathways. ACS Chem Biol 2012; 7:1994-2003. [PMID: 22991895 PMCID: PMC3528841 DOI: 10.1021/cb300385m] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sulfated molecules with diverse functions are common in biology, but sulfonation as a method to activate a metabolite for chemical catalysis is rare. Catalytic activity was characterized and crystal structures were determined for two such "activating" sulfotransferases (STs) that sulfonate β-hydroxyacyl thioester substrates. The CurM polyketide synthase (PKS) ST domain from the curacin A biosynthetic pathway of Moorea producens and the olefin synthase (OLS) ST from a hydrocarbon-producing system of Synechococcus PCC 7002 both occur as a unique acyl carrier protein (ACP), ST, and thioesterase (TE) tridomain within a larger polypeptide. During pathway termination, these cyanobacterial systems introduce a terminal double bond into the β-hydroxyacyl-ACP-linked substrate by the combined action of the ST and TE. Under in vitro conditions, CurM PKS ST and OLS ST acted on β-hydroxy fatty acyl-ACP substrates; however, OLS ST was not reactive toward analogues of the natural PKS ST substrate bearing a C5-methoxy substituent. The crystal structures of CurM ST and OLS ST revealed that they are members of a distinct protein family relative to other prokaryotic and eukaryotic sulfotransferases. A common binding site for the sulfonate donor 3'-phosphoadenosine-5'-phosphosulfate was visualized in complexes with the product 3'-phosphoadenosine-5'-phosphate. Critical functions for several conserved amino acids in the active site were confirmed by site-directed mutagenesis, including a proposed glutamate catalytic base. A dynamic active-site flap unique to the "activating" ST family affects substrate selectivity and product formation, based on the activities of chimeras of the PKS and OLS STs with exchanged active-site flaps.
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Affiliation(s)
- Jennifer Gehret McCarthy
- Life Sciences Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Eli B. Eisman
- Life Sciences Institute and Chemical Biology Doctoral Program, University of Michigan, Ann Arbor, MI 48109
| | - Sarang Kulkarni
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260
| | - David H. Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology University of Michigan, Ann Arbor, MI 48109
| | - Janet L. Smith
- Life Sciences Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109
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34
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Xu W, Qiao K, Tang Y. Structural analysis of protein-protein interactions in type I polyketide synthases. Crit Rev Biochem Mol Biol 2012; 48:98-122. [PMID: 23249187 DOI: 10.3109/10409238.2012.745476] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Polyketide synthases (PKSs) are responsible for synthesizing a myriad of natural products with agricultural, medicinal relevance. The PKSs consist of multiple functional domains of which each can catalyze a specified chemical reaction leading to the synthesis of polyketides. Biochemical studies showed that protein-substrate and protein-protein interactions play crucial roles in these complex regio-/stereo-selective biochemical processes. Recent developments on X-ray crystallography and protein NMR techniques have allowed us to understand the biosynthetic mechanism of these enzymes from their structures. These structural studies have facilitated the elucidation of the sequence-function relationship of PKSs and will ultimately contribute to the prediction of product structure. This review will focus on the current knowledge of type I PKS structures and the protein-protein interactions in this system.
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Affiliation(s)
- Wei Xu
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
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35
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Yuzawa S, Kim W, Katz L, Keasling JD. Heterologous production of polyketides by modular type I polyketide synthases in Escherichia coli. Curr Opin Biotechnol 2012; 23:727-35. [DOI: 10.1016/j.copbio.2011.12.029] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 12/19/2011] [Accepted: 12/21/2011] [Indexed: 11/15/2022]
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36
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Liu Q, Yao F, Chooi YH, Kang Q, Xu W, Li Y, Shao Y, Shi Y, Deng Z, Tang Y, You D. Elucidation of Piericidin A1 biosynthetic locus revealed a thioesterase-dependent mechanism of α-pyridone ring formation. ACTA ACUST UNITED AC 2012; 19:243-53. [PMID: 22365607 DOI: 10.1016/j.chembiol.2011.12.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 11/25/2011] [Accepted: 12/22/2011] [Indexed: 12/23/2022]
Abstract
Piericidins are a class of α-pyridone antibiotics that inhibit mitochondrial respiratory chain and exhibit antimicrobial, antifungal, and antitumor activities. Sequential analysis of Streptomyces piomogeues var. Hangzhouwanensis genome revealed six modular polyketide synthases, an amidotransferase, two methyltransferases, and a monooxygenase for piericidin A1 production. Gene functional analysis and deletion results provide overview of the biosynthesis pathway. Furthermore, in vitro characterization of the terminal polyketide synthase module with the thioesterase domain using β-ketoacyl substrates was performed. That revealed a pathway where the α-pyridone ring formation is dependent on hydrolysis of the product β, δ-diketo carboxylic acid by the C-terminal thioesterase followed by amidation and cyclization. These findings set the stage to investigate unusual enzymatic mechanisms in α-pyridone antibiotics biosynthesis, provide a foundation for genome mining of α-pyridone antibiotics, and produce analogs by molecular engineering.
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Affiliation(s)
- Qian Liu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China
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37
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Kim D, Nah JH, Choi SS, Shin HS, Sherman DH, Kim ES. Biological activities of an engineered tautomycetin analogue via disruption of tmcR-encoding hydroxylase in Streptomyces sp. CK4412. J Ind Microbiol Biotechnol 2012; 39:1563-8. [PMID: 22733296 DOI: 10.1007/s10295-012-1157-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 05/31/2012] [Indexed: 11/25/2022]
Abstract
Tautomycetin (TMC), originally isolated from Streptomyces griseochromogenes, has been reported to possess biological functions including T cell-specific immunosuppressive and anticancer activities through a mechanism of differential inhibition of protein phosphatases such as PP1, PP2A, and SHP2. Independently isolated Streptomyces sp. CK4412 was also reported to produce a structurally identical TMC compound. Previously, we isolated and characterized the entire TMC biosynthetic gene cluster from Streptomyces sp. CK4412. In silico database comparison revealed a 1,359-bp tmcR as a putative bacterial Cytochrome P450 hydroxylase gene in the TMC biosynthetic gene cluster. Through targeted gene disruption and complementation, the tmcR mutant was confirmed to produce a C5-deoxy-TMC, the same analogue produced by the S. griseochromogenes ttnI mutant, implying that TmcR behaves as a regiospecific C5-oxygenase in the TMC biosynthetic pathway in Streptomyces sp. CK4412. In particular, the C5-deoxy-TMC from the tmcR mutant exhibited 3.2-fold higher inhibition activity toward SHP2 with significantly reduced inhibition activities toward PP1, and human Vero and lung cancer cells. These results suggested that C5 regiospecific modification of the TMC polyketide moiety may result in a drug development target for use in preferentially enhancing immunosuppressive activity while minimizing its undesirable biological activities.
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Affiliation(s)
- Dongju Kim
- Department of Biological Engineering, Inha University, Incheon 402-751, Korea
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38
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Akey DL, Gehret JJ, Khare D, Smith JL. Insights from the sea: structural biology of marine polyketide synthases. Nat Prod Rep 2012; 29:1038-49. [PMID: 22498975 DOI: 10.1039/c2np20016c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The world's oceans are a rich source of natural products with extremely interesting chemistry. Biosynthetic pathways have been worked out for a few, and the story is being enriched with crystal structures of interesting pathway enzymes. By far, the greatest number of structural insights from marine biosynthetic pathways has originated with studies of curacin A, a poster child for interesting marine chemistry with its cyclopropane and thiazoline rings, internal cis double bond, and terminal alkene. Using the curacin A pathway as a model, structural details are now available for a novel loading enzyme with remarkable dual decarboxylase and acetyltransferase activities, an Fe(2+)/α-ketoglutarate-dependent halogenase that dictates substrate binding order through conformational changes, a decarboxylase that establishes regiochemistry for cyclopropane formation, and a thioesterase with specificity for β-sulfated substrates that lead to terminal alkene offloading. The four curacin A pathway dehydratases reveal an intrinsic flexibility that may accommodate bulky or stiff polyketide intermediates. In the salinosporamide A pathway, active site volume determines the halide specificity of a halogenase that catalyzes for the synthesis of a halogenated building block. Structures of a number of putative polyketide cyclases may help in understanding reaction mechanisms and substrate specificities although their substrates are presently unknown.
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Affiliation(s)
- David L Akey
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
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39
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40
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Whicher JR, Florova G, Sydor PK, Singh R, Alhamadsheh M, Challis GL, Reynolds KA, Smith JL. Structure and function of the RedJ protein, a thioesterase from the prodiginine biosynthetic pathway in Streptomyces coelicolor. J Biol Chem 2011; 286:22558-69. [PMID: 21543318 PMCID: PMC3121400 DOI: 10.1074/jbc.m110.213512] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prodiginines are a class of red-pigmented natural products with immunosuppressant, anticancer, and antimalarial activities. Recent studies on prodiginine biosynthesis in Streptomyces coelicolor have elucidated the function of many enzymes within the pathway. However, the function of RedJ, which was predicted to be an editing thioesterase based on sequence similarity, is unknown. We report here the genetic, biochemical, and structural characterization of the redJ gene product. Deletion of redJ in S. coelicolor leads to a 75% decrease in prodiginine production, demonstrating its importance for prodiginine biosynthesis. RedJ exhibits thioesterase activity with selectivity for substrates having long acyl chains and lacking a β-carboxyl substituent. The thioesterase has 1000-fold greater catalytic efficiency with substrates linked to an acyl carrier protein (ACP) than with the corresponding CoA thioester substrates. Also, RedJ strongly discriminates against the streptomycete ACP of fatty acid biosynthesis in preference to RedQ, an ACP of the prodiginine pathway. The 2.12 Å resolution crystal structure of RedJ provides insights into the molecular basis for the observed substrate selectivity. A hydrophobic pocket in the active site chamber is positioned to bind long acyl chains, as suggested by a long-chain ligand from the crystallization solution bound in this pocket. The accessibility of the active site is controlled by the position of a highly flexible entrance flap. These data combined with previous studies of prodiginine biosynthesis in S. coelicolor support a novel role for RedJ in facilitating transfer of a dodecanoyl chain from one acyl carrier protein to another en route to the key biosynthetic intermediate 2-undecylpyrrole.
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Affiliation(s)
- Jonathan R Whicher
- Chemical Biology Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
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41
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Gehret JJ, Gu L, Gerwick WH, Wipf P, Sherman DH, Smith JL. Terminal alkene formation by the thioesterase of curacin A biosynthesis: structure of a decarboxylating thioesterase. J Biol Chem 2011; 286:14445-54. [PMID: 21357626 PMCID: PMC3077644 DOI: 10.1074/jbc.m110.214635] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/25/2011] [Indexed: 11/06/2022] Open
Abstract
Curacin A is a polyketide synthase (PKS)-non-ribosomal peptide synthetase-derived natural product with potent anticancer properties generated by the marine cyanobacterium Lyngbya majuscula. Type I modular PKS assembly lines typically employ a thioesterase (TE) domain to off-load carboxylic acid or macrolactone products from an adjacent acyl carrier protein (ACP) domain. In a striking departure from this scheme the curacin A PKS employs tandem sulfotransferase and TE domains to form a terminal alkene moiety. Sulfotransferase sulfonation of β-hydroxy-acyl-ACP is followed by TE hydrolysis, decarboxylation, and sulfate elimination (Gu, L., Wang, B., Kulkarni, A., Gehret, J. J., Lloyd, K. R., Gerwick, L., Gerwick, W. H., Wipf, P., Håkansson, K., Smith, J. L., and Sherman, D. H. (2009) J. Am. Chem. Soc. 131, 16033-16035). With low sequence identity to other PKS TEs (<15%), the curacin TE represents a new thioesterase subfamily. The 1.7-Å curacin TE crystal structure reveals how the familiar α/β-hydrolase architecture is adapted to specificity for β-sulfated substrates. A Ser-His-Glu catalytic triad is centered in an open active site cleft between the core domain and a lid subdomain. Unlike TEs from other PKSs, the lid is fixed in an open conformation on one side by dimer contacts of a protruding helix and on the other side by an arginine anchor from the lid into the core. Adjacent to the catalytic triad, another arginine residue is positioned to recognize the substrate β-sulfate group. The essential features of the curacin TE are conserved in sequences of five other putative bacterial ACP-ST-TE tridomains. Formation of a sulfate leaving group as a biosynthetic strategy to facilitate acyl chain decarboxylation is of potential value as a route to hydrocarbon biofuels.
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Affiliation(s)
- Jennifer J. Gehret
- From the Departments of Biological Chemistry
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - Liangcai Gu
- Medicinal Chemistry
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - William H. Gerwick
- the Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093, and
| | - Peter Wipf
- the Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - David H. Sherman
- Medicinal Chemistry
- Chemistry, and
- Microbiology and Immunology, and
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - Janet L. Smith
- From the Departments of Biological Chemistry
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
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42
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Abstract
Natural product biosynthetic pathways have evolved enzymes with myriad activities that represent an expansive array of chemical transformations for constructing secondary metabolites. Recently, harnessing the biosynthetic potential of these enzymes through chemoenzymatic synthesis has provided a powerful tool that often rivals the most sophisticated methodologies in modern synthetic chemistry and provides new opportunities for accessing chemical diversity. Herein, we describe our research efforts with enzymes from a broad collection of biosynthetic systems, highlighting recent progress in this exciting field.
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Affiliation(s)
- Jonathan D. Mortison
- Life Sciences Institute, Department of Chemistry and Department of Medicinal Chemistry, 210 Washtenaw Avenue, University of Michigan, Ann Arbor, Michigan 48109
| | - David H. Sherman
- Life Sciences Institute, Department of Chemistry and Department of Medicinal Chemistry, 210 Washtenaw Avenue, University of Michigan, Ann Arbor, Michigan 48109
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