1
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Koizumi Y, Nakajima Y, Tanaka Y, Matsui K, Sakabe M, Maeda K, Sato M, Koshino H, Sato S, Kimura M, Takahashi-Ando N. A Role in 15-Deacetylcalonectrin Acetylation in the Non-Enzymatic Cyclization of an Earlier Bicyclic Intermediate in Fusarium Trichothecene Biosynthesis. Int J Mol Sci 2024; 25:4288. [PMID: 38673874 PMCID: PMC11050026 DOI: 10.3390/ijms25084288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
The trichothecene biosynthesis in Fusarium begins with the cyclization of farnesyl pyrophosphate to trichodiene, followed by subsequent oxygenation to isotrichotriol. This initial bicyclic intermediate is further cyclized to isotrichodermol (ITDmol), a tricyclic precursor with a toxic trichothecene skeleton. Although the first cyclization and subsequent oxygenation are catalyzed by enzymes encoded by Tri5 and Tri4, the second cyclization occurs non-enzymatically. Following ITDmol formation, the enzymes encoded by Tri101, Tri11, Tri3, and Tri1 catalyze 3-O-acetylation, 15-hydroxylation, 15-O-acetylation, and A-ring oxygenation, respectively. In this study, we extensively analyzed the metabolites of the corresponding pathway-blocked mutants of Fusarium graminearum. The disruption of these Tri genes, except Tri3, led to the accumulation of tricyclic trichothecenes as the main products: ITDmol due to Tri101 disruption; a mixture of isotrichodermin (ITD), 7-hydroxyisotrichodermin (7-HIT), and 8-hydroxyisotrichodermin (8-HIT) due to Tri11 disruption; and a mixture of calonectrin and 3-deacetylcalonectrin due to Tri1 disruption. However, the ΔFgtri3 mutant accumulated substantial amounts of bicyclic metabolites, isotrichotriol and trichotriol, in addition to tricyclic 15-deacetylcalonectrin (15-deCAL). The ΔFgtri5ΔFgtri3 double gene disruptant transformed ITD into 7-HIT, 8-HIT, and 15-deCAL. The deletion of FgTri3 and overexpression of Tri6 and Tri10 trichothecene regulatory genes did not result in the accumulation of 15-deCAL in the transgenic strain. Thus, the absence of Tri3p and/or the presence of a small amount of 15-deCAL adversely affected the non-enzymatic second cyclization and C-15 hydroxylation steps.
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Affiliation(s)
- Yoshiaki Koizumi
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
| | - Yuichi Nakajima
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Yuya Tanaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Kosuke Matsui
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Masato Sakabe
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
| | - Kazuyuki Maeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Masayuki Sato
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Hiroyuki Koshino
- Molecular Structure Characterization Unit, Technology Platform Division, Center for Sustainable Resource Science (CSRS) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Soichi Sato
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
| | - Makoto Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Naoko Takahashi-Ando
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
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2
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Harms V, Kirschning A, Dickschat JS. Nature-driven approaches to non-natural terpene analogues. Nat Prod Rep 2020; 37:1080-1097. [DOI: 10.1039/c9np00055k] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The reactions catalysed by terpene synthases belong to the most complex and fascinating cascade-type transformations in Nature.
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Affiliation(s)
- Vanessa Harms
- Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ)
- Leibniz Universität Hannover
- 30167 Hannover
- Germany
| | - Andreas Kirschning
- Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ)
- Leibniz Universität Hannover
- 30167 Hannover
- Germany
| | - Jeroen S. Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry
- University of Bonn
- 53121 Bonn
- Germany
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3
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Burkhardt I, Dickschat JS. The absolute configuration of isochamigrene: new insights into the cyclisation mechanism of trichodiene synthase. Chem Commun (Camb) 2018; 54:3540-3542. [DOI: 10.1039/c8cc01744a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The enantioselective synthesis of isochamigrene clarified its absolute configuration and biosynthetic relation to trichodiene.
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Affiliation(s)
- Immo Burkhardt
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn
- 53121 Bonn
- Germany
| | - Jeroen S. Dickschat
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn
- 53121 Bonn
- Germany
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4
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Abstract
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The
year 2017 marks the twentieth anniversary of terpenoid cyclase
structural biology: a trio of terpenoid cyclase structures reported
together in 1997 were the first to set the foundation for understanding
the enzymes largely responsible for the exquisite chemodiversity of
more than 80000 terpenoid natural products. Terpenoid cyclases catalyze
the most complex chemical reactions in biology, in that more than
half of the substrate carbon atoms undergo changes in bonding and
hybridization during a single enzyme-catalyzed cyclization reaction.
The past two decades have witnessed structural, functional, and computational
studies illuminating the modes of substrate activation that initiate
the cyclization cascade, the management and manipulation of high-energy
carbocation intermediates that propagate the cyclization cascade,
and the chemical strategies that terminate the cyclization cascade.
The role of the terpenoid cyclase as a template for catalysis is paramount
to its function, and protein engineering can be used to reprogram
the cyclization cascade to generate alternative and commercially important
products. Here, I review key advances in terpenoid cyclase structural
and chemical biology, focusing mainly on terpenoid cyclases and related
prenyltransferases for which X-ray crystal structures have informed
and advanced our understanding of enzyme structure and function.
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Affiliation(s)
- David W Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
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5
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Maeda K, Nakajima Y, Motoyama T, Kondoh Y, Kawamura T, Kanamaru K, Ohsato S, Nishiuchi T, Yoshida M, Osada H, Kobayashi T, Kimura M. Identification of a trichothecene production inhibitor by chemical array and library screening using trichodiene synthase as a target protein. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2017; 138:1-7. [PMID: 28456298 DOI: 10.1016/j.pestbp.2017.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/20/2017] [Accepted: 03/21/2017] [Indexed: 06/07/2023]
Abstract
Trichothecene mycotoxins often accumulate in apparently normal grains of cereal crops. In an effort to develop an agricultural chemical to reduce trichothecene contamination, we screened trichothecene production inhibitors from the compounds on the chemical arrays. By using the trichodiene (TDN) synthase tagged with hexahistidine (rTRI5) as a target protein, 32 hit compounds were obtained from chemical library of the RIKEN Natural Product Depository (NPDepo) by chemical array screening. At 10μgmL-1, none of the 32 chemicals inhibited trichothecene production by Fusarium graminearum in liquid culture. Against the purified rTRI5 enzyme, however, NPD10133 [progesterone 3-(O-carboxymethyl)oxime amide-bonded to phenylalanine] showed weak inhibitory activity at 10μgmL-1 (18.7μM). For the screening of chemicals inhibiting trichothecene accumulation in liquid culture, 20 analogs of NPD10133 selected from the NPDepo chemical library were assayed. At 10μM, only NPD352 [testosterone 3-(O-carboxymethyl)oxime amide-bonded to phenylalanine methyl ester] inhibited rTRI5 activity and trichothecene production. Kinetic analysis suggested that the enzyme inhibition was of a mixed-type. The identification of NPD352 as a TDN synthase inhibitor lays the foundation for the development of a more potent inhibitor via systematic introduction of wide structural diversity on the gonane skeleton and amino acid residues.
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Affiliation(s)
- Kazuyuki Maeda
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan; Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
| | - Yuichi Nakajima
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan; Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takayuki Motoyama
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yasumitsu Kondoh
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tatsuro Kawamura
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kyoko Kanamaru
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Shuichi Ohsato
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
| | - Takumi Nishiuchi
- Division of Functional Genomics, Advanced Science Research Centre, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-0934, Japan
| | - Minoru Yoshida
- Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroyuki Osada
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tetsuo Kobayashi
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Makoto Kimura
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
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Li Z, Gao R, Hao Q, Zhao H, Cheng L, He F, Liu L, Liu X, Chou WKW, Zhu H, Cane DE. The T296V Mutant of Amorpha-4,11-diene Synthase Is Defective in Allylic Diphosphate Isomerization but Retains the Ability To Cyclize the Intermediate (3R)-Nerolidyl Diphosphate to Amorpha-4,11-diene. Biochemistry 2016; 55:6599-6604. [PMID: 27933789 DOI: 10.1021/acs.biochem.6b01004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The T296V mutant of amorpha-4,11-diene synthase catalyzes the abortive conversion of the natural substrate (E,E)-farnesyl diphosphate mainly into the acyclic product (E)-β-farnesene (88%) instead of the natural bicyclic sesquiterpene amorphadiene (7%). Incubation of the T296V mutant with (3R,6E)-nerolidyl diphosphate resulted in cyclization to amorphadiene. Analysis of additional mutants of amino acid residue 296 and in vitro assays with the intermediate analogue (2Z,6E)-farnesyl diphosphate as well as (3S,6E)-nerolidyl diphosphate demonstrated that the T296V mutant can no longer catalyze the allylic rearrangement of farnesyl diphosphate to the normal intermediate (3R,6E)-nerolidyl diphosphate, while retaining the ability to cyclize (3R,6E)-nerolidyl diphosphate to amorphadiene. The T296A mutant predominantly retained amorphadiene synthase activity, indicating that neither the hydroxyl nor the methyl group of the Thr296 side chain is required for cyclase activity.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Wayne K W Chou
- Department of Chemistry, Brown University , Box H, Providence, Rhode Island 02912-9108, United States
| | | | - David E Cane
- Department of Chemistry, Brown University , Box H, Providence, Rhode Island 02912-9108, United States
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7
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Faraldos JA, Miller DJ, González V, Yoosuf-Aly Z, Cascón O, Li A, Allemann RK. A 1,6-ring closure mechanism for (+)-δ-cadinene synthase? J Am Chem Soc 2012; 134:5900-8. [PMID: 22397618 DOI: 10.1021/ja211820p] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recombinant (+)-δ-cadinene synthase (DCS) from Gossypium arboreum catalyzes the metal-dependent cyclization of (E,E)-farnesyl diphosphate (FDP) to the cadinane sesquiterpene δ-cadinene, the parent hydrocarbon of cotton phytoalexins such as gossypol. In contrast to some other sesquiterpene cyclases, DCS carries out this transformation with >98% fidelity but, as a consequence, leaves no mechanistic traces of its mode of action. The formation of (+)-δ-cadinene has been shown to occur via the enzyme-bound intermediate (3R)-nerolidyl diphosphate (NDP), which in turn has been postulated to be converted to cis-germacradienyl cation after a 1,10-cyclization. A subsequent 1,3-hydride shift would then relocate the carbocation within the transient macrocycle to expedite a second cyclization that yields the cadinenyl cation with the correct cis stereochemistry found in (+)-δ-cadinene. An elegant 1,10-mechanistic pathway that avoids the formation of (3R)-NDP has also been suggested. In this alternative scenario, the final cadinenyl cation is proposed to be formed through the intermediacy of trans, trans-germacradienyl cation and germacrene D. In addition, an alternative 1,6-ring closure mechanism via the bisabolyl cation has previously been envisioned. We report here a detailed investigation of the catalytic mechanism of DCS using a variety of mechanistic probes including, among others, deuterated and fluorinated FDPs. Farnesyl diphosphate analogues with fluorine at C2 and C10 acted as inhibitors of DCS, but intriguingly, after prolonged overnight incubations, they yielded 2F-germacrene(s) and a 10F-humulene, respectively. The observed 1,10-, and to a lesser extent, 1,11-cyclization activity of DCS with these fluorinated substrates is consistent with the postulated macrocyclization mechanism(s) en route to (+)-δ-cadinene. On the other hand, mechanistic results from incubations of DCS with 6F-FPP, (2Z,6E)-FDP, neryl diphosphate, 6,7-dihydro-FDP, and NDP seem to be in better agreement with the potential involvement of the alternative biosynthetic 1,6-ring closure pathway. In particular, the strong inhibition of DCS by 6F-FDP, coupled to the exclusive bisabolyl- and terpinyl-derived product profiles observed for the DCS-catalyzed turnover of (2Z,6E)-farnesyl and neryl diphosphates, suggested the intermediacy of α-bisabolyl cation. DCS incubations with enantiomerically pure [1-(2)H(1)](1R)-FDP revealed that the putative bisabolyl-derived 1,6-pathway proceeds through (3R)-nerolidyl diphosphate (NDP), is consistent with previous deuterium-labeling studies, and accounts for the cis stereochemistry characteristic of cadinenyl-derived sesquiterpenes. While the results reported here do not unambiguously rule in favor of 1,6- or 1,10-cyclization, they demonstrate the mechanistic versatility inherent to DCS and highlight the possible existence of multiple mechanistic pathways.
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Affiliation(s)
- Juan A Faraldos
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, United Kingdom
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8
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Doud EH, Perlstein DL, Wolpert M, Cane DE, Walker S. Two distinct mechanisms for TIM barrel prenyltransferases in bacteria. J Am Chem Soc 2011; 133:1270-3. [PMID: 21214173 PMCID: PMC3033458 DOI: 10.1021/ja109578b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reactions of two bacterial TIM barrel prenyltransferases (PTs), MoeO5 and PcrB, were explored. MoeO5, the enzyme responsible for the first step in moenomycin biosynthesis, catalyzes the transfer of farnesyl to 3-phosphoglyceric acid (3PG) to give a product containing a cis-allylic double bond. We show that this reaction involves isomerization to a nerolidyl pyrophosphate intermediate followed by bond rotation prior to attack by the nucleophile. This mechanism is unprecedented for a prenyltransferase that catalyzes an intermolecular coupling. We also show that PcrB transfers geranyl and geranylgeranyl groups to glycerol-1-phosphate (G1P), making it the first known bacterial enzyme to use G1P as a substrate. Unlike MoeO5, PcrB catalyzes prenyl transfer without isomerization to give products that retain the trans-allylic bond of the prenyl donors. The TIM barrel family of PTs is unique in including enzymes that catalyze prenyl transfer by distinctly different reaction mechanisms.
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Lopez-Gallego F, Agger SA, Abate-Pella D, Distefano MD, Schmidt-Dannert C. Sesquiterpene synthases Cop4 and Cop6 from Coprinus cinereus: catalytic promiscuity and cyclization of farnesyl pyrophosphate geometric isomers. Chembiochem 2010; 11:1093-106. [PMID: 20419721 DOI: 10.1002/cbic.200900671] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sesquiterpene synthases catalyze with different catalytic fidelity the cyclization of farnesyl pyrophosphate (FPP) into hundreds of known compounds with diverse structures and stereochemistries. Two sesquiterpene synthases, Cop4 and Cop6, were previously isolated from Coprinus cinereus as part of a fungal genome survey. This study investigates the reaction mechanism and catalytic fidelity of the two enzymes. Cyclization of all-trans-FPP ((E,E)-FPP) was compared to the cyclization of the cis-trans isomer of FPP ((Z,E)-FPP) as a surrogate for the secondary cisoid neryl cation intermediate generated by sesquiterpene synthases, which are capable of isomerizing the C2--C3 pi bond of all-trans-FPP. Cop6 is a "high-fidelity" alpha-cuprenene synthase that retains its fidelity under various conditions tested. Cop4 is a catalytically promiscuous enzyme that cyclizes (E,E)-FPP into multiple products, including (-)-germacrene D and cubebol. Changing the pH of the reaction drastically alters the fidelity of Cop4 and makes it a highly selective enzyme. Cyclization of (Z,E)-FPP by Cop4 and Cop6 yields products that are very different from those obtained with (E,E)-FPP. Conversion of (E,E)-FPP proceeds via a (6R)-beta-bisabolyl carbocation in the case of Cop6 and an (E,E)-germacradienyl carbocation in the case of Cop4. However, (Z,E)-FPP is cyclized via a (6S)-beta-bisabolene carbocation by both enzymes. Structural modeling suggests that differences in the active site and the loop that covers the active site of the two enzymes might explain their different catalytic fidelities.
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10
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Hong YJ, Tantillo DJ. A tangled web—interconnecting pathways to amorphadiene and the amorphene sesquiterpenes. Chem Sci 2010. [DOI: 10.1039/c0sc00333f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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11
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Cane DE. Terpenoid cyclases: design and function of electrophilic catalysts. CIBA FOUNDATION SYMPOSIUM 2007; 171:163-76; discussion 176-83. [PMID: 1302176 DOI: 10.1002/9780470514344.ch10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Terpenoid cyclases catalyse the cyclization of the universal acyclic precursors geranyl and farnesyl diphosphate to monoterpenes and sesquiterpenes, respectively. All such cyclases investigated to date are operationally soluble, moderately lipophilic proteins of relative molecular weight 40,000-100,000, requiring no cofactors other than a divalent metal, usually Mg2+ and occasionally Mn2+. The focus of most work has been on the mechanisms of the cyclization reactions themselves. It is currently proposed that the cyclase binds the acyclic substrate in a suitable conformation and initiates the cyclization by ionization of the labile allylic diphosphate moiety. The use of stereospecifically labelled substrates and analysis of the sites of labelling in the derived cyclization products has allowed the proposal of detailed cyclization mechanisms. Further insight into the architecture and function of the cyclase active site has come from the study of substrate and intermediate analogues designed to act as potential inhibitors or anomalous substrates of the normal cyclization reaction. Progress has also been made on the cloning of the relevant structural genes for sesquiterpene cyclases. This has led to new insights into the basic requirements for cyclase catalysis and specificity.
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, RI 02912
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12
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Affiliation(s)
- David W Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
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13
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Metzler DE, Metzler CM, Sauke DJ. Enzymatic Addition, Elimination, Condensation, and Isomerization. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50016-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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15
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Cyclization Enzymes in the Biosynthesis of Monoterpenes, Sesquiterpenes, and Diterpenes. BIOSYNTHESIS 2000. [DOI: 10.1007/3-540-48146-x_2] [Citation(s) in RCA: 284] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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16
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Abstract
The 10-cyclopropylidene analog of farnesyl diphosphate was shown to be a mechanism-based inhibitor of trichodiene synthase with an inactivation rate (k(inact)) of 0.010 +/- 0.0003 min(-1) and an apparent Ki of 663 +/- 75 nM. The presence of three anomalous sesquiterpene products detected in incubation mixtures indicate that the compound also serves as a substrate of the enzyme.
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, RI 02912, USA
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Affiliation(s)
- P M Dewick
- Department of Pharmaceutical Sciences, University of Nottingham, UK
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19
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Cane DE, Sohng JK, Lamberson CR, Rudnicki SM, Wu Z, Lloyd MD, Oliver JS, Hubbard BR. Pentalenene synthase. Purification, molecular cloning, sequencing, and high-level expression in Escherichia coli of a terpenoid cyclase from Streptomyces UC5319. Biochemistry 1994; 33:5846-57. [PMID: 8180213 DOI: 10.1021/bi00185a024] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Pentalenene synthase, which catalyzes the cyclization of farnesyl diphosphate (1) to the tricyclic sesquiterpene hydrocarbon pentalenene (2), was purified from Streptomyces UC5319. A 450-bp hybridization probe, generated by PCR amplification of genomic DNA using primers based on N-terminal and internal tryptic peptide sequence data for pentalenene synthase, was used to screen both plasmid and phage DNA libraries of Streptomyces genomic DNA, resulting in the isolation and sequencing of the complete pentalenene synthase gene. PCR was used to insert the pentalenene synthase gene into the T7 expression vector pLM1. Cloning of the resulting construct in the expression host Escherichia coli BL21 (DE3) gave transformants that expressed pentalenene synthase as greater than 10% of soluble protein. The recombinant enzyme has been purified, and initial physical and kinetic characterization has been performed. The recombinant enzyme appears to be identical in every respect with the native Streptomyces synthase and exhibits the following steady-state kinetic parameters: Km = 0.31 +/- 0.05 microM, kcat = 0.32 +/- s-1, KI(PPi) = 3.2 +/- 0.6 microM. Both enzymes have an absolute requirement of Mg2+ for catalysis and an optimum pH of 8.2-8.4. Both proteins have M(r) values of 41-42 kDa, as determined by SDS-PAGE.
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
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