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Wenger ES, Martinie RJ, Ushimaru R, Pollock CJ, Sil D, Li A, Hoang N, Palowitch GM, Graham BP, Schaperdoth I, Burke EJ, Maggiolo AO, Chang WC, Allen BD, Krebs C, Silakov A, Boal AK, Bollinger JM. Optimized Substrate Positioning Enables Switches in the C-H Cleavage Site and Reaction Outcome in the Hydroxylation-Epoxidation Sequence Catalyzed by Hyoscyamine 6β-Hydroxylase. J Am Chem Soc 2024; 146:24271-24287. [PMID: 39172701 PMCID: PMC11374477 DOI: 10.1021/jacs.4c04406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
Hyoscyamine 6β-hydroxylase (H6H) is an iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenase that produces the prolifically administered antinausea drug, scopolamine. After its namesake hydroxylation reaction, H6H then couples the newly installed C6 oxygen to C7 to produce the drug's epoxide functionality. Oxoiron(IV) (ferryl) intermediates initiate both reactions by cleaving C-H bonds, but it remains unclear how the enzyme switches the target site and promotes (C6)O-C7 coupling in preference to C7 hydroxylation in the second step. In one possible epoxidation mechanism, the C6 oxygen would─analogously to mechanisms proposed for the Fe/2OG halogenases and, in our more recent study, N-acetylnorloline synthase (LolO)─coordinate as alkoxide to the C7-H-cleaving ferryl intermediate to enable alkoxyl coupling to the ensuing C7 radical. Here, we provide structural and kinetic evidence that H6H does not employ substrate coordination or repositioning for the epoxidation step but instead exploits the distinct spatial dependencies of competitive C-H cleavage (C6 vs C7) and C-O-coupling (oxygen rebound vs cyclization) steps to promote the two-step sequence. Structural comparisons of ferryl-mimicking vanadyl complexes of wild-type H6H and a variant that preferentially 7-hydroxylates instead of epoxidizing 6β-hydroxyhyoscyamine suggest that a modest (∼10°) shift in the Fe-O-H(C7) approach angle is sufficient to change the outcome. The 7-hydroxylation:epoxidation partition ratios of both proteins increase more than 5-fold in 2H2O, reflecting an epoxidation-specific requirement for cleavage of the alcohol O-H bond, which, unlike in the LolO oxacyclization, is not accomplished by iron coordination in advance of C-H cleavage.
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Affiliation(s)
- Eliott S Wenger
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | | | - Richiro Ushimaru
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Pan J, Wenger ES, Lin CY, Zhang B, Sil D, Schaperdoth I, Saryazdi S, Grossman RB, Krebs C, Bollinger JM. An Unusual Ferryl Intermediate and Its Implications for the Mechanism of Oxacyclization by the Loline-Producing Iron(II)- and 2-Oxoglutarate-Dependent Oxygenase, LolO. Biochemistry 2024; 63:1674-1683. [PMID: 38898603 PMCID: PMC11219260 DOI: 10.1021/acs.biochem.4c00166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
N-Acetylnorloline synthase (LolO) is one of several iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases that catalyze sequential reactions of different types in the biosynthesis of valuable natural products. LolO hydroxylates C2 of 1-exo-acetamidopyrrolizidine before coupling the C2-bonded oxygen to C7 to form the tricyclic loline core. Each reaction requires cleavage of a C-H bond by an oxoiron(IV) (ferryl) intermediate; however, different carbons are targeted, and the carbon radicals have different fates. Prior studies indicated that the substrate-cofactor disposition (SCD) controls the site of H· abstraction and can affect the reaction outcome. These indications led us to determine whether a change in SCD from the first to the second LolO reaction might contribute to the observed reactivity switch. Whereas the single ferryl complex in the C2 hydroxylation reaction was previously shown to have typical Mössbauer parameters, one of two ferryl complexes to accumulate during the oxacyclization reaction has the highest isomer shift seen to date for such a complex and abstracts H· from C7 ∼ 20 times faster than does the first ferryl complex in its previously reported off-pathway hydroxylation of C7. The detectable hydroxylation of C7 in competition with cyclization by the second ferryl complex is not enhanced in 2H2O solvent, suggesting that the C2 hydroxyl is deprotonated prior to C7-H cleavage. These observations are consistent with the coordination of the C2 oxygen to the ferryl complex, which may reorient its oxo ligand, the substrate, or both to positions more favorable for C7-H cleavage and oxacyclization.
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Affiliation(s)
- Juan Pan
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: New England Biolabs, Ipswich, Massachusetts 01938, United States
| | - Eliott S. Wenger
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Chi-Yun Lin
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Bo Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: The Janssen Pharmaceutical Companies of Johnson & Johnson, Spring House, Pennsylvania 19477, United States
| | - Debangsu Sil
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Chemistry, Indian Institute of Science Education and Research, Pune 411008, India
| | - Irene Schaperdoth
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Engineering, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Setareh Saryazdi
- Department of Chemistry, The University of Kentucky, Lexington, Kentucky 40506, United States
- Present address: College of Pharmacy, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Robert B. Grossman
- Department of Chemistry, The University of Kentucky, Lexington, Kentucky 40506, United States
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - J. Martin Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Zhu W, Liu S, Zhao K, Ye G, Huang K, He Z. Revealing a Double-Volcano-Like Structure-Activity Relationship for Substitution-Functionalized Metal-Phthalocyanine Catalysts toward Electrochemical CO 2 Reduction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306144. [PMID: 37715327 DOI: 10.1002/smll.202306144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/21/2023] [Indexed: 09/17/2023]
Abstract
Electron-donating/-withdrawing groups (EDGs/EWGs) substitution is widely used to regulate the catalytic performance of transition-metal phthalocyanine (MPc) toward electrochemical CO2 reduction, but the corresponding structure-activity relationships and regulation mechanisms are still ambiguous. Herein, by investigating a series of substitution-functionalized MPc (MPc-X), this work reveals a double-volcano-like relationship between the electron-donating/-withdrawing abilities of the substituents and the catalytic activities of MPc-X. The weak-EDG/-EWG substitution enhances whereas the strong-EDG/-EWG substitution mostly lowers the CO selectivity of MPc. Experimental and calculation results demonstrate that the electronic properties of the substituents influence the symmetry and energy of the highest occupied molecular orbitals of MPc-X, which in turn determine the CO2 adsorption/activation and lead to diverse CO2 reduction pathways on the EWG or EDG substituted MPc via different CO2 adsorption modes. This work provides mechanism insights that could be guidance for the design and regulation of molecular catalysts.
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Affiliation(s)
- Weiwei Zhu
- College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Chemical Power Sources, Central South University, Changsha, Hunan, 410083, P. R. China
| | - Suqin Liu
- College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Chemical Power Sources, Central South University, Changsha, Hunan, 410083, P. R. China
| | - Kuangmin Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, P. R. China
| | - Guanying Ye
- College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Chemical Power Sources, Central South University, Changsha, Hunan, 410083, P. R. China
| | - Kui Huang
- College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Chemical Power Sources, Central South University, Changsha, Hunan, 410083, P. R. China
| | - Zhen He
- College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Chemical Power Sources, Central South University, Changsha, Hunan, 410083, P. R. China
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Wilson RH, Chatterjee S, Smithwick ER, Dalluge JJ, Bhagi-Damodaran A. Role of Secondary Coordination Sphere Residues in Halogenation Catalysis of Non-heme Iron Enzymes. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- R. Hunter Wilson
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Sourav Chatterjee
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Elizabeth R. Smithwick
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Joseph J. Dalluge
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Ambika Bhagi-Damodaran
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, Minnesota 55455, United States
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Song S, Jiang Y, Chen R, Su W, Liang W, Yang D, Li J, Zhang W, Gao S, Yuan B, Qu G, Sun Z. Whole-cell Biotransformation of Penicillin G by a Three-enzyme Co-expression System with Engineered Deacetoxycephalosporin C Synthase. Chembiochem 2022; 23:e202200179. [PMID: 35384232 DOI: 10.1002/cbic.202200179] [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: 03/30/2022] [Revised: 04/06/2022] [Indexed: 11/10/2022]
Abstract
Deacetoxycephalosporin C synthase (DAOCS) catalyzes the tranformation of penicillin G to phenylacetyl-7-aminodeacetoxycephalosporanic acid (G-7-ADCA) in dependence on 2-oxoglutarate (2OG). However, the low activity of DAOCS and the expense of 2OG restricted the practical application in the production of G-7-ADCA. Herein, a rational design campaign was performed on a DAOCS from Streptomyces clavuligerus (scDAOCS) in the quest to construct novel expandases. The resulting mutants showed 25~58% increase in activity compared to the template. The dominant DAOCS variants were then embeded into a three-enzyme co-expression system, consisting of a catalase and a L-glutamic oxidase for the generation of 2OG, to convert penicillin G into G-7-ADCA in E. coli . The engineered whole-cell enzyme cascade was applied on an up scaled reaction, exhibiting a yield of G-7-ADCA up to 39.21 mM (14.6 g·L -1 ) with a conversion of 78.42 mol%. This work highlights the potential of the integrated whole-cell system that may inspire further research on green and efficient production of 7-ADCA.
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Affiliation(s)
- Shiyi Song
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Yingying Jiang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Ruidong Chen
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Wencheng Su
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, Tianjin, CHINA
| | - Weinan Liang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Dameng Yang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, CHINA
| | - Jincheng Li
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Wuyuan Zhang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Shushan Gao
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Bo Yuan
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Ge Qu
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, National Enyzme Engineering Lab, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, Tianjin, CHINA
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Wojdyla Z, Borowski T. Properties of the Reactants and Their Interactions within and with the Enzyme Binding Cavity Determine Reaction Selectivities. The Case of Fe(II)/2-Oxoglutarate Dependent Enzymes. Chemistry 2022; 28:e202104106. [PMID: 34986268 DOI: 10.1002/chem.202104106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 12/12/2022]
Abstract
Fe(II)/2-oxoglutarate dependent dioxygenases (ODDs) share a double stranded beta helix (DSBH) fold and utilise a common reactive intermediate, ferryl species, to catalyse oxidative transformations of substrates. Despite the structural similarities, ODDs accept a variety of substrates and facilitate a wide range of reactions, that is hydroxylations, desaturations, (oxa)cyclisations and ring rearrangements. In this review we present and discuss the factors contributing to the observed (regio)selectivities of ODDs. They span from inherent properties of the reactants, that is, substrate molecule and iron cofactor, to the interactions between the substrate and the enzyme's binding cavity; the latter can counterbalance the effect of the former. Based on results of both experimental and computational studies dedicated to ODDs, we also line out the properties of the reactants which promote reaction outcomes other than the "default" hydroxylation. It turns out that the reaction selectivity depends on a delicate balance of interactions between the components of the investigated system.
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Affiliation(s)
- Zuzanna Wojdyla
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Niezapominajek 8, 30239 Krakow, Poland
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Niezapominajek 8, 30239 Krakow, Poland
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Niu X, Zhang J, Xue X, Wang D, Wang L, Gao Q. Deacetoxycephalosporin C synthase (expandase): Research progress and application potential. Synth Syst Biotechnol 2021; 6:396-401. [PMID: 34901478 PMCID: PMC8626558 DOI: 10.1016/j.synbio.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Cephalosporins play an indispensable role against bacterial infections. Deacetyloxycephalosporin C synthase (DAOCS), also called expandase, is a key enzyme in cephalosporin biosynthesis that epoxides penicillin to form the hexavalent thiazide ring of cephalosporin. DAOCS in fungus Acremonium chrysogenum was identified as a bifunctional enzyme with both ring expansion and hydroxylation, whereas two separate enzymes in bacteria catalyze these two reactions. In this review, we briefly summarize its source and function, improvement of the conversion rate of penicillin to deacetyloxycephalosporin C through enzyme modification, crystallography features, the prediction of the active site, and application perspective.
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Affiliation(s)
- Xiaofan Niu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jian Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Xianli Xue
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Depei Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,National Demonstration Center for Experimental Bioengineering Education (Tianjin University of Science and Technology), Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Lin Wang
- College of Artificial Intelligence, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Qiang Gao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,National Demonstration Center for Experimental Bioengineering Education (Tianjin University of Science and Technology), Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
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8
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Effect of high pressure carbon dioxide on the browning inhibition of sugar-preserved orange peel. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101467] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Liu T, Abboud MI, Chowdhury R, Tumber A, Hardy AP, Lippl K, Lohans CT, Pires E, Wickens J, McDonough MA, West CM, Schofield CJ. Biochemical and biophysical analyses of hypoxia sensing prolyl hydroxylases from Dictyostelium discoideum and Toxoplasma gondii. J Biol Chem 2020; 295:16545-16561. [PMID: 32934009 PMCID: PMC7864055 DOI: 10.1074/jbc.ra120.013998] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/14/2020] [Indexed: 12/30/2022] Open
Abstract
In animals, the response to chronic hypoxia is mediated by prolyl hydroxylases (PHDs) that regulate the levels of hypoxia-inducible transcription factor α (HIFα). PHD homologues exist in other types of eukaryotes and prokaryotes where they act on non HIF substrates. To gain insight into the factors underlying different PHD substrates and properties, we carried out biochemical and biophysical studies on PHD homologues from the cellular slime mold, Dictyostelium discoideum, and the protozoan parasite, Toxoplasma gondii, both lacking HIF. The respective prolyl-hydroxylases (DdPhyA and TgPhyA) catalyze prolyl-hydroxylation of S-phase kinase-associated protein 1 (Skp1), a reaction enabling adaptation to different dioxygen availability. Assays with full-length Skp1 substrates reveal substantial differences in the kinetic properties of DdPhyA and TgPhyA, both with respect to each other and compared with human PHD2; consistent with cellular studies, TgPhyA is more active at low dioxygen concentrations than DdPhyA. TgSkp1 is a DdPhyA substrate and DdSkp1 is a TgPhyA substrate. No cross-reactivity was detected between DdPhyA/TgPhyA substrates and human PHD2. The human Skp1 E147P variant is a DdPhyA and TgPhyA substrate, suggesting some retention of ancestral interactions. Crystallographic analysis of DdPhyA enables comparisons with homologues from humans, Trichoplax adhaerens, and prokaryotes, informing on differences in mobile elements involved in substrate binding and catalysis. In DdPhyA, two mobile loops that enclose substrates in the PHDs are conserved, but the C-terminal helix of the PHDs is strikingly absent. The combined results support the proposal that PHD homologues have evolved kinetic and structural features suited to their specific sensing roles.
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Affiliation(s)
- Tongri Liu
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Martine I Abboud
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Anthony Tumber
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Adam P Hardy
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Kerstin Lippl
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Elisabete Pires
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - James Wickens
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Christopher M West
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
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10
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Liu Y, Shi J, Liu Y. Mechanistic Insights into the Oxidative Ring Expansion from Penicillin N to Deacetoxycephalosporin C Catalyzed by a Nonheme Iron(II) and α-KG-Dependent Oxygenase. Inorg Chem 2020; 59:12218-12231. [PMID: 32822181 DOI: 10.1021/acs.inorgchem.0c01211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Deacetoxycephalosporin C synthase (DAOCS) is a nonheme iron(II) and 2-oxoglutarate (α-KG)-dependent oxygenase that catalyzes the oxidative ring expansion of penicillin N (penN) to deacetoxycephalosporin C (DAOC). Earlier reported crystal structures of DAOCS indicated that the substrate penicillin binds at the same site of succinate, leading to the proposal of the unusual "ping-pong" mechanism. However, more recent data provided evidence of the formation of ternary DAOCS·α-KG·penN complex, and thus DAOCS should follow the usual consensus mechanism of α-KG-dependent nonheme iron(II) oxygenases. Nevertheless, how DAOCS catalyzes the ring expansion is unknown. In this paper, on the basis of the crystal structure, we constructed two reactant models and performed a series of combined quantum mechanics/molecular mechanics (QM/MM) calculations to illuminate the catalysis of DAOCS. The binding mode of substrate was found to be crucial in determining which hydrogen atom in two methyl groups is first abstracted and whether the second H-abstraction to be abstracted in the final desaturation step locates in a suitable orientation. The highly reactive FeIV-oxo species prefers to abstract a hydrogen atom from one of two methyl groups in penN to trigger the ring arrangement. After the H-abstraction, the generated methylene radical intermediate can easily initiate the ring arrangement. First, the C-S bond cleaves to generate a thiyl radical, which is in concert with the formation of the terminal C═C double bond; the newly generated thiyl radical then rapidly shifts to the more stable tertiary C atom to complete ring expansion. In the final step, the FeIII-OH species abstracts the second hydrogen to give the desaturated DAOC product. During the catalysis, no active site residue is directly involved in the chemistry, which implies that the other pocket residues except the coordinate ones with iron play a role only in anchoring the substrate.
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Affiliation(s)
- Yaru Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Junyou Shi
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, Yunnan 655011, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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11
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Groszmann M, Chandler PM, Ross JJ, Swain SM. Manipulating Gibberellin Control Over Growth and Fertility as a Possible Target for Managing Wild Radish Weed Populations in Cropping Systems. FRONTIERS IN PLANT SCIENCE 2020; 11:190. [PMID: 32265944 PMCID: PMC7096587 DOI: 10.3389/fpls.2020.00190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 02/07/2020] [Indexed: 05/22/2023]
Abstract
Wild radish is a major weed of Australian cereal crops. A rapid establishment, fast growth, and abundant seed production are fundamental to its success as an invasive species. Wild radish has developed resistance to a number of commonly used herbicides increasing the problem. New innovative approaches are needed to control wild radish populations. Here we explore the possibility of pursuing gibberellin (GA) biosynthesis as a novel molecular target for controlling wild radish, and in doing so contribute new insights into GA biology. By characterizing ga 3-oxidase (ga3ox) mutants in Arabidopsis, a close taxonomic relative to wild radish, we showed that even mild GA deficiencies cause considerable reductions in growth and fecundity. This includes an explicit requirement for GA biosynthesis in successful female fertility. Similar defects were reproducible in wild radish via chemical inhibition of GA biosynthesis, confirming GA action as a possible new target for controlling wild radish populations. Two possible targeting approaches are considered; the first would involve developing a species-specific inhibitor that selectively inhibits GA production in wild radish over cereal crops. The second, involves making crop species insensitive to GA repression, allowing the use of existing broad spectrum GA inhibitors to control wild radish populations. Toward the first concept, we cloned and characterized two wild radish GA3OX genes, identifying protein differences that appear sufficient for selective inhibition of dicot over monocot GA3OX activity. We developed a novel yeast-based approach to assay GA3OX activity as part of the molecular characterization, which could be useful for future screening of inhibitory compounds. For the second approach, we demonstrated that a subset of GA associated sln1/Rht-1 overgrowth mutants, recently generated in cereals, are insensitive to GA reductions brought on by the general GA biosynthesis inhibitor, paclobutrazol. The location of these mutations within sln1/Rht-1, offers additional insight into the functional domains of these important GA signaling proteins. Our early assessment suggests that targeting the GA pathway could be a viable inclusion into wild radish management programs that warrants further investigation. In drawing this conclusion, we provided new insights into GA regulated reproductive development and molecular characteristics of GA metabolic and signaling proteins.
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Affiliation(s)
- Michael Groszmann
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Peter M. Chandler
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - John J. Ross
- School of Biological Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Steve M. Swain
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
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12
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Evaluation of a concerted vs. sequential oxygen activation mechanism in α-ketoglutarate-dependent nonheme ferrous enzymes. Proc Natl Acad Sci U S A 2020; 117:5152-5159. [PMID: 32094179 DOI: 10.1073/pnas.1922484117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Determining the requirements for efficient oxygen (O2) activation is key to understanding how enzymes maintain efficacy and mitigate unproductive, often detrimental reactivity. For the α-ketoglutarate (αKG)-dependent nonheme iron enzymes, both a concerted mechanism (both cofactor and substrate binding prior to reaction with O2) and a sequential mechanism (cofactor binding and reaction with O2 precede substrate binding) have been proposed. Deacetoxycephalosporin C synthase (DAOCS) is an αKG-dependent nonheme iron enzyme for which both of these mechanisms have been invoked to generate an intermediate that catalyzes oxidative ring expansion of penicillin substrates in cephalosporin biosynthesis. Spectroscopy shows that, in contrast to other αKG-dependent enzymes (which are six coordinate when only αKG is bound to the FeII), αKG binding to FeII-DAOCS results in ∼45% five-coordinate sites that selectively react with O2 relative to the remaining six-coordinate sites. However, this reaction produces an FeIII species that does not catalyze productive ring expansion. Alternatively, simultaneous αKG and substrate binding to FeII-DAOCS produces five-coordinate sites that rapidly react with O2 to form an FeIV=O intermediate that then reacts with substrate to produce cephalosporin product. These results demonstrate that the concerted mechanism is operative in DAOCS and by extension, other nonheme iron enzymes.
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13
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Pan J, Wenger ES, Matthews ML, Pollock CJ, Bhardwaj M, Kim AJ, Allen BD, Grossman RB, Krebs C, Bollinger JM. Evidence for Modulation of Oxygen Rebound Rate in Control of Outcome by Iron(II)- and 2-Oxoglutarate-Dependent Oxygenases. J Am Chem Soc 2019; 141:15153-15165. [PMID: 31475820 DOI: 10.1021/jacs.9b06689] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases generate iron(IV)-oxo (ferryl) intermediates that can abstract hydrogen from aliphatic carbons (R-H). Hydroxylation proceeds by coupling of the resultant substrate radical (R•) and oxygen of the Fe(III)-OH complex ("oxygen rebound"). Nonhydroxylation outcomes result from different fates of the Fe(III)-OH/R• state; for example, halogenation results from R• coupling to a halogen ligand cis to the hydroxide. We previously suggested that halogenases control substrate-cofactor disposition to disfavor oxygen rebound and permit halogen coupling to prevail. Here, we explored the general implication that, when a ferryl intermediate can ambiguously target two substrate carbons for different outcomes, rebound to the site capable of the alternative outcome should be slower than to the adjacent, solely hydroxylated site. We evaluated this prediction for (i) the halogenase SyrB2, which exclusively hydroxylates C5 of norvaline appended to its carrier protein but can either chlorinate or hydroxylate C4 and (ii) two bifunctional enzymes that normally hydroxylate one carbon before coupling that oxygen to a second carbon (producing an oxacycle) but can, upon encountering deuterium at the first site, hydroxylate the second site instead. In all three cases, substrate hydroxylation incorporates a greater fraction of solvent-derived oxygen at the site that can also undergo the alternative outcome than at the other site, most likely reflecting an increased exchange of the initially O2-derived oxygen ligand in the longer-lived Fe(III)-OH/R• states. Suppression of rebound may thus be generally important for nonhydroxylation outcomes by these enzymes.
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Affiliation(s)
| | | | | | | | - Minakshi Bhardwaj
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40546-0312 , United States
| | | | | | - Robert B Grossman
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40546-0312 , United States
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Wang Z, Wang S, Wu M, Li Z, Liu P, Li F, Chen Q, Yang A, Yang J. Evolutionary and functional analyses of the 2-oxoglutarate-dependent dioxygenase genes involved in the flavonoid biosynthesis pathway in tobacco. PLANTA 2019; 249:543-561. [PMID: 30293202 DOI: 10.1007/s00425-018-3019-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/23/2018] [Indexed: 05/27/2023]
Abstract
MAIN CONCLUSION This study illustrates the differences in the gene structure of 2-oxoglutarate-dependent oxygenase involved in flavonoid biosynthesis (2ODD-IFB), and their potential roles in regulating tobacco flavonoid biosynthesis and plant growth. Flavonol synthase (FLS), anthocyanidin synthase (ANS), and flavanone 3β-hydroxylase belong to the 2-oxoglutarate-dependent (2ODD) oxygenase family, and each performs crucial functions in the biosynthesis of flavonoids. We identified two NtFLS genes, two NtANS genes, and four NtF3H genes from Nicotiana tabacum genome, as well as their homologous genes in the N. sylvestris and N. tomentosiformis genomes. Our phylogenetic analysis indicated that these three types of genes split from each other before the divergence of gymnosperms and angiosperms. FLS evolved faster in the eudicot plants, whereas ANS evolved faster in the monocot plants. Gene structure analysis revealed two fragment insertions occurred at different times in the intron one position of tobacco FLS genes. Homologous protein modeling revealed distinct structures in the N terminus of the tobacco 2ODD oxygenases. We found that the expression patterns of genes encoding tobacco 2ODD oxygenases in flavonoids biosynthesis (2ODD-IFB) did not determine the accumulation patterns of flavonoids among various tobacco tissues, but strongly affected the concentration of flavonoids in the tissues, where they were biosynthesized. More carbon resource flowed to the flavonol biosynthesis when NtANS gene was silenced, otherwise more anthocyanidin accumulated when NtFLS gene was repressed. This study illustrates the 2ODD-IFB gene structure evolution, differences among their protein structures, and provides a foundation for regulating plant development and altering flavonoid content and/or composition through the manipulation of plant 2ODD-IFB genes.
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Affiliation(s)
- Zhong Wang
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Shanshan Wang
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Mingzhu Wu
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Zefeng Li
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Pingping Liu
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Feng Li
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Qiansi Chen
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Aiguo Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jun Yang
- China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China.
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15
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Rabe P, Kamps JJAG, Schofield CJ, Lohans CT. Roles of 2-oxoglutarate oxygenases and isopenicillin N synthase in β-lactam biosynthesis. Nat Prod Rep 2018; 35:735-756. [PMID: 29808887 PMCID: PMC6097109 DOI: 10.1039/c8np00002f] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 01/01/2023]
Abstract
Covering: up to 2017 2-Oxoglutarate (2OG) dependent oxygenases and the homologous oxidase isopenicillin N synthase (IPNS) play crucial roles in the biosynthesis of β-lactam ring containing natural products. IPNS catalyses formation of the bicyclic penicillin nucleus from a tripeptide. 2OG oxygenases catalyse reactions that diversify the chemistry of β-lactams formed by both IPNS and non-oxidative enzymes. Reactions catalysed by the 2OG oxygenases of β-lactam biosynthesis not only involve their typical hydroxylation reactions, but also desaturation, epimerisation, rearrangement, and ring-forming reactions. Some of the enzymes involved in β-lactam biosynthesis exhibit remarkable substrate and product selectivities. We review the roles of 2OG oxygenases and IPNS in β-lactam biosynthesis, highlighting opportunities for application of knowledge of their roles, structures, and mechanisms.
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Affiliation(s)
- Patrick Rabe
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Jos J A G Kamps
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Christopher J Schofield
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Christopher T Lohans
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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16
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Abstract
Enzymes in biosynthetic pathways, especially in plant and microbial metabolism, generate structural and functional group complexity in small molecules by conversion of acyclic frameworks to cyclic scaffolds via short, efficient routes. The distinct chemical logic used by several distinct classes of cyclases, oxidative and non-oxidative, has recently been elucidated by genome mining, heterologous expression, and genetic and mechanistic analyses. These include enzymes performing pericyclic transformations, pyran synthases, tandem acting epoxygenases, and epoxide "hydrolases", as well as oxygenases and radical S-adenosylmethionine enzymes that involve rearrangements of substrate radicals under aerobic or anaerobic conditions.
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Affiliation(s)
- Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, Stanford, CA
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA
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Abstract
Oxidative cyclizations are important transformations that occur widely during natural product biosynthesis. The transformations from acyclic precursors to cyclized products can afford morphed scaffolds, structural rigidity, and biological activities. Some of the most dramatic structural alterations in natural product biosynthesis occur through oxidative cyclization. In this Review, we examine the different strategies used by nature to create new intra(inter)molecular bonds via redox chemistry. This Review will cover both oxidation- and reduction-enabled cyclization mechanisms, with an emphasis on the former. Radical cyclizations catalyzed by P450, nonheme iron, α-KG-dependent oxygenases, and radical SAM enzymes are discussed to illustrate the use of molecular oxygen and S-adenosylmethionine to forge new bonds at unactivated sites via one-electron manifolds. Nonradical cyclizations catalyzed by flavin-dependent monooxygenases and NAD(P)H-dependent reductases are covered to show the use of two-electron manifolds in initiating cyclization reactions. The oxidative installations of epoxides and halogens into acyclic scaffolds to drive subsequent cyclizations are separately discussed as examples of "disappearing" reactive handles. Last, oxidative rearrangement of rings systems, including contractions and expansions, will be covered.
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Affiliation(s)
- Man-Cheng Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Yi Zou
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (ChEM-H), Stanford University, 443 Via Ortega, Stanford, CA 94305
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA
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18
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Dunbar KL, Scharf DH, Litomska A, Hertweck C. Enzymatic Carbon-Sulfur Bond Formation in Natural Product Biosynthesis. Chem Rev 2017; 117:5521-5577. [PMID: 28418240 DOI: 10.1021/acs.chemrev.6b00697] [Citation(s) in RCA: 356] [Impact Index Per Article: 50.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sulfur plays a critical role for the development and maintenance of life on earth, which is reflected by the wealth of primary metabolites, macromolecules, and cofactors bearing this element. Whereas a large body of knowledge has existed for sulfur trafficking in primary metabolism, the secondary metabolism involving sulfur has long been neglected. Yet, diverse sulfur functionalities have a major impact on the biological activities of natural products. Recent research at the genetic, biochemical, and chemical levels has unearthed a broad range of enzymes, sulfur shuttles, and chemical mechanisms for generating carbon-sulfur bonds. This Review will give the first systematic overview on enzymes catalyzing the formation of organosulfur natural products.
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Affiliation(s)
- Kyle L Dunbar
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Daniel H Scharf
- Life Sciences Institute, University of Michigan , 210 Washtenaw Avenue, Ann Arbor, Michigan 48109-2216, United States
| | - Agnieszka Litomska
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany.,Friedrich Schiller University , 07743 Jena, Germany
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19
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Modified Deacetylcephalosporin C Synthase for the Biotransformation of Semisynthetic Cephalosporins. Appl Environ Microbiol 2016; 82:3711-3720. [PMID: 27084018 DOI: 10.1128/aem.00174-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/06/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Deacetylcephalosporin C synthase (DACS), a 2-oxoglutarate-dependent oxygenase synthesized by Streptomyces clavuligerus, transforms an inert methyl group of deacetoxycephalosporin C (DAOC) into an active hydroxyl group of deacetylcephalosporin C (DAC) during the biosynthesis of cephalosporin. It is a step which is chemically difficult to accomplish, but its development by use of an enzymatic method with DACS can facilitate a cost-effective technology for the manufacture of semisynthetic cephalosporin intermediates such as 7-amino-cephalosporanic acid (7ACA) and hydroxymethyl-7-amino-cephalosporanic acid (HACA) from cephalosporin G. As the native enzyme showed negligible activity toward cephalosporin G, an unnatural and less expensive substrate analogue, directed-evolution strategies such as random, semirational, rational, and computational methods were used for systematic engineering of DACS for improved activity. In comparison to the native enzyme, several variants with improved catalytic efficiency were found. The enzyme was stable for several days and is expressed in soluble form at high levels with significantly higher kcat/Km values. The efficacy and industrial scalability of one of the selected variants, CefFGOS, were demonstrated in a process showing complete bioconversion of 18 g/liter of cephalosporin G into deacetylcephalosporin G (DAG) in about 80 min and showed reproducible results at higher substrate concentrations as well. DAG could be converted completely into HACA in about 30 min by a subsequent reaction, thus facilitating scalability toward commercialization. The experimental findings with several mutants were also used to rationalize the functional conformation deduced from homology modeling, and this led to the disclosure of critical regions involved in the catalysis of DACS. IMPORTANCE 7ACA and HACA serve as core intermediates for the manufacture of several semisynthetic cephalosporins. As they are expensive, a cost-effective enzyme technology for the manufacture of these intermediates is required. Deacetylcephalosporin C synthase (DACS) was identified as a candidate enzyme for the development of technology from cephalosporin G in this study. Directed-evolution strategies were employed to enhance the catalytic efficiency of deacetylcephalosporin C synthase. One of the selected mutants of deacetylcephalosporin C synthase could convert high concentrations of cephalosporin G into DAG, which subsequently could be converted into HACA completely. As cephalosporin G is inexpensive and readily available, the technology would lead to a substantial reduction in the cost for these intermediates upon commercialization.
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20
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Structural Insights into Substrate Specificity of Feruloyl-CoA 6'-Hydroxylase from Arabidopsis thaliana. Sci Rep 2015; 5:10355. [PMID: 25993561 PMCID: PMC4438608 DOI: 10.1038/srep10355] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/09/2015] [Indexed: 01/13/2023] Open
Abstract
Coumarins belong to an important class of plant secondary metabolites. Feruloyl-CoA 6’-hydroxylase (F6’H), a 2-oxoglutarate dependent dioxygenase (2OGD), catalyzes a pivotal step in the biosynthesis of a simple coumarin scopoletin. In this study, we determined the 3-dimensional structure of the F6’H1 apo enzyme by X-ray crystallography. It is the first reported structure of a 2OGD enzyme involved in coumarin biosynthesis and closely resembles the structure of Arabidopsis thaliana anthocyanidin synthase. To better understand the mechanism of enzyme catalysis and substrate specificity, we also generated a homology model of a related ortho-hydroxylase (C2’H) from sweet potato. By comparing these two structures, we targeted two amino acid residues and verified their roles in substrate binding and specificity by site-directed mutagenesis.
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21
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Andersson I, Valegård K. 2-Oxoglutarate-Dependent Oxygenases of Cephalosporin Synthesis. 2-OXOGLUTARATE-DEPENDENT OXYGENASES 2015. [DOI: 10.1039/9781782621959-00385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Central steps in the biosynthetic pathways of some of the most commonly used antibiotics, the cephalosporins, are catalysed by 2-oxoglutarate (2OG)-dependent oxygenases. Deacetoxycephalosporin C synthase (DAOCS) catalyses the 2OG-dependent oxidative expansion of the five-membered thiazolidine ring of the penicillin nucleus into the six-membered dihydrothiazine ring of the cephalosporin nucleus. DAOCS uses dioxygen to create a reactive iron–oxygen intermediate from ferrous ion to drive the reaction. In prokaryotic cephalosporin producers, the cephalosporin product, DAOC, is hydroxylated at the 3′-position to form deacetylcephalosporin C (DAC) as catalysed by a second 2OG-dependent enzyme, DAC synthase (DACS). In eukaryotic cephalosporin producers, the reaction is catalysed by a bifunctional enzyme, DAOC/DACS, that catalyses both the ring expansion and the 3′-hydroxylation reactions. The prokaryotic and eukaryotic enzymes are closely related to DAOCS by sequence, suggesting these enzymes may have evolved by gene duplication. Cephamycin C-producing microorganisms use two enzymes, encoded by the genes cmcI/J, to convert cephalosporins to their 7α-methoxy derivatives that are less vulnerable to β-lactam hydrolysing enzymes. The methoxylation reaction is dependent on Fe(ii), 2OG and S-adenosylmethionine, suggesting the involvement of another 2OG-dependent oxygenase. Herein, structural and mechanistic features are summarized for these 2OG enzymes that utilize this common and flexible mode of dioxygen activation.
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Affiliation(s)
- Inger Andersson
- Department of Cell and Molecular Biology, Uppsala University Box 596, S-751 24 Uppsala Sweden
| | - Karin Valegård
- Department of Cell and Molecular Biology, Uppsala University Box 596, S-751 24 Uppsala Sweden
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22
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Tarhonskaya H, Szöllössi A, Leung IKH, Bush JT, Henry L, Chowdhury R, Iqbal A, Claridge TDW, Schofield CJ, Flashman E. Studies on Deacetoxycephalosporin C Synthase Support a Consensus Mechanism for 2-Oxoglutarate Dependent Oxygenases. Biochemistry 2014; 53:2483-93. [DOI: 10.1021/bi500086p] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Hanna Tarhonskaya
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Andrea Szöllössi
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Ivanhoe K. H. Leung
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Jacob T. Bush
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Luc Henry
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Rasheduzzaman Chowdhury
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Aman Iqbal
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Timothy D. W. Claridge
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Christopher J. Schofield
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Emily Flashman
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
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23
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Cheng AX, Han XJ, Wu YF, Lou HX. The function and catalysis of 2-oxoglutarate-dependent oxygenases involved in plant flavonoid biosynthesis. Int J Mol Sci 2014; 15:1080-95. [PMID: 24434621 PMCID: PMC3907857 DOI: 10.3390/ijms15011080] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 12/26/2013] [Accepted: 12/29/2013] [Indexed: 12/22/2022] Open
Abstract
Flavonoids are secondary metabolites derived from phenylalanine and acetate metabolism. They fulfil a variety of functions in plants and have health benefits for humans. During the synthesis of the tricyclic flavonoid natural products in plants, oxidative modifications to the central C ring are catalyzed by four of FeII and 2-oxoglutarate dependent (2-ODD) oxygenases, namely flavone synthase I (FNS I), flavonol synthase (FLS), anthocyanidin synthase (ANS) and flavanone 3β-hydroxylase (FHT). FNS I, FLS and ANS are involved in desaturation of C2–C3 of flavonoids and FHT in hydroxylation of C3. FNS I, which is restricted to the Apiaceae species and in rice, is predicted to have evolved from FHT by duplication. Due to their sequence similarity and substrate specificity, FLS and ANS, which interact with the α surface of the substrate, belong to a group of dioxygenases having a broad substrate specificity, while FNS I and FHT are more selective, and interact with the naringenin β surface. Here, we summarize recent findings regarding the function of the four 2-ODD oxygenases and the relationship between their catalytic activity, their polypeptide sequence and their tertiary structure.
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Affiliation(s)
- Ai-Xia Cheng
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, No. 44 West Wenhua Road, Jinan 250012, China.
| | - Xiao-Juan Han
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, No. 44 West Wenhua Road, Jinan 250012, China.
| | - Yi-Feng Wu
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, No. 44 West Wenhua Road, Jinan 250012, China.
| | - Hong-Xiang Lou
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, No. 44 West Wenhua Road, Jinan 250012, China.
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24
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Vogt M, Nerush A, Diskin-Posner Y, Ben-David Y, Milstein D. Reversible CO2 binding triggered by metal–ligand cooperation in a rhenium(i) PNP pincer-type complex and the reaction with dihydrogen. Chem Sci 2014. [DOI: 10.1039/c4sc00130c] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Metal–ligand cooperation in a rhenium PNP pincer complex gives rise to the reversible activation of CO2 and H2 and the efficient catalytic decomposition of formic acid under base-free conditions.
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Affiliation(s)
- Matthias Vogt
- The Weizmann Institute of Science
- Department of Organic Chemistry
- Rehovot, Israel
| | - Alexander Nerush
- The Weizmann Institute of Science
- Department of Organic Chemistry
- Rehovot, Israel
| | - Yael Diskin-Posner
- The Weizmann Institute of Science
- Department of Chemical Research Support
- Rehovot, Israel
| | - Yehoshoa Ben-David
- The Weizmann Institute of Science
- Department of Organic Chemistry
- Rehovot, Israel
| | - David Milstein
- The Weizmann Institute of Science
- Department of Organic Chemistry
- Rehovot, Israel
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25
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Recent advances in the biosynthesis of penicillins, cephalosporins and clavams and its regulation. Biotechnol Adv 2013; 31:287-311. [DOI: 10.1016/j.biotechadv.2012.12.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 11/23/2022]
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26
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Hamed RB, Gomez-Castellanos JR, Henry L, Ducho C, McDonough MA, Schofield CJ. The enzymes of β-lactam biosynthesis. Nat Prod Rep 2013; 30:21-107. [DOI: 10.1039/c2np20065a] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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27
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Aik W, McDonough MA, Thalhammer A, Chowdhury R, Schofield CJ. Role of the jelly-roll fold in substrate binding by 2-oxoglutarate oxygenases. Curr Opin Struct Biol 2012; 22:691-700. [PMID: 23142576 DOI: 10.1016/j.sbi.2012.10.001] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 09/20/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
2-Oxoglutarate (2OG) and ferrous iron dependent oxygenases catalyze two-electron oxidations of a range of small and large molecule substrates, including proteins/peptides/amino acids, nucleic acids/bases, and lipids, as well as natural products including antibiotics and signaling molecules. 2OG oxygenases employ variations of a core double-stranded β-helix (DSBH; a.k.a. jelly-roll, cupin or jumonji C (JmjC)) fold to enable binding of Fe(II) and 2OG in a subfamily conserved manner. The topology of the DSBH limits regions directly involved in substrate binding: commonly the first, second and eighth strands, loops between the second/third and fourth/fifth DSBH strands, and the N-terminal and C-terminal regions are involved in primary substrate, co-substrate and cofactor binding. Insights into substrate recognition by 2OG oxygenases will help to enable selective inhibition and bioengineering studies.
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Affiliation(s)
- WeiShen Aik
- Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, United Kingdom
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28
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Li T, Huo L, Pulley C, Liu A. Decarboxylation mechanisms in biological system. Bioorg Chem 2012; 43:2-14. [PMID: 22534166 DOI: 10.1016/j.bioorg.2012.03.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 03/04/2012] [Accepted: 03/19/2012] [Indexed: 11/30/2022]
Abstract
This review examines the mechanisms propelling cofactor-independent, organic cofactor-dependent and metal-dependent decarboxylase chemistry. Decarboxylation, the removal of carbon dioxide from organic acids, is a fundamentally important reaction in biology. Numerous decarboxylase enzymes serve as key components of aerobic and anaerobic carbohydrate metabolism and amino acid conversion. In the past decade, our knowledge of the mechanisms enabling these crucial decarboxylase reactions has continued to expand and inspire. This review focuses on the organic cofactors biotin, flavin, NAD, pyridoxal 5'-phosphate, pyruvoyl, and thiamin pyrophosphate as catalytic centers. Significant attention is also placed on the metal-dependent decarboxylase mechanisms.
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Affiliation(s)
- Tingfeng Li
- Department of Biochemistry, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA
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29
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Albiero E, Ruggeri M, Fortuna S, Finotto S, Bernardi M, Madeo D, Rodeghiero F. Isolated erythrocytosis: study of 67 patients and identification of three novel germ-line mutations in the prolyl hydroxylase domain protein 2 (PHD2) gene. Haematologica 2011; 97:123-7. [PMID: 21828119 DOI: 10.3324/haematol.2010.039545] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The oxygen sensing pathway modulates erythropoietin expression. In normal cells, intracellular oxygen tensions are directly sensed by prolyl hydroxylase domain (PHD)-containing proteins. PHD2 isozyme has a key role in tagging hypoxia-inducible factor (HIF)-α subunits for polyubiquitination and proteasomal degradation. Erythrocytosis-associated PHD2 mutations reduce hydroxylation of HIF-α. The investigation of 67 patients with isolated erythrocytosis, either sporadic or familial, allowed the identification of three novel mutations in the catalytic domain of the PHD2 protein. All new mutations are germ-line, heterozygous and missense, and code for a predicted full length mutant PHD2 protein. Identification of the disease-causing genes will be of critical importance for a better classification of familial and acquired erythrocytosis, offering additional insight into the erythropoietin regulating oxygen sensing pathway.
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Affiliation(s)
- Elena Albiero
- Department of Cellular Therapies and Haematology, San Bortolo Hospital, Vicenza, Italy
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30
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Chowdhury R, Yeoh KK, Tian YM, Hillringhaus L, Bagg EA, Rose NR, Leung IKH, Li XS, Woon ECY, Yang M, McDonough MA, King ON, Clifton IJ, Klose RJ, Claridge TDW, Ratcliffe PJ, Schofield CJ, Kawamura A. The oncometabolite 2-hydroxyglutarate inhibits histone lysine demethylases. EMBO Rep 2011; 12:463-9. [PMID: 21460794 PMCID: PMC3090014 DOI: 10.1038/embor.2011.43] [Citation(s) in RCA: 771] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 02/21/2011] [Accepted: 02/22/2011] [Indexed: 02/07/2023] Open
Abstract
Mutations in isocitrate dehydrogenases (IDHs) have a gain-of-function effect leading to R(-)-2-hydroxyglutarate (R-2HG) accumulation. By using biochemical, structural and cellular assays, we show that either or both R- and S-2HG inhibit 2-oxoglutarate (2OG)-dependent oxygenases with varying potencies. Half-maximal inhibitory concentration (IC(50)) values for the R-form of 2HG varied from approximately 25 μM for the histone N(ɛ)-lysine demethylase JMJD2A to more than 5 mM for the hypoxia-inducible factor (HIF) prolyl hydroxylase. The results indicate that candidate oncogenic pathways in IDH-associated malignancy should include those that are regulated by other 2OG oxygenases than HIF hydroxylases, in particular those involving the regulation of histone methylation.
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Affiliation(s)
- Rasheduzzaman Chowdhury
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
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31
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Rose NR, McDonough MA, King ONF, Kawamura A, Schofield CJ. Inhibition of 2-oxoglutarate dependent oxygenases. Chem Soc Rev 2011; 40:4364-97. [PMID: 21390379 DOI: 10.1039/c0cs00203h] [Citation(s) in RCA: 307] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
2-Oxoglutarate (2OG) dependent oxygenases are ubiquitous iron enzymes that couple substrate oxidation to the conversion of 2OG to succinate and carbon dioxide. In humans their roles include collagen biosynthesis, fatty acid metabolism, DNA repair, RNA and chromatin modifications, and hypoxic sensing. Commercial applications of 2OG oxygenase inhibitors began with plant growth retardants, and now extend to a clinically used pharmaceutical compound for cardioprotection. Several 2OG oxygenases are now being targeted for therapeutic intervention for diseases including anaemia, inflammation and cancer. In this critical review, we describe studies on the inhibition of 2OG oxygenases, focusing on small molecules, and discuss the potential of 2OG oxygenases as therapeutic targets (295 references).
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Affiliation(s)
- Nathan R Rose
- Department of Chemistry and the Oxford Centre for Integrative Systems Biology, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
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32
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Wu XB, Tian XY, Ji JJ, Wu WB, Fan KQ, Yang KQ. Saturation mutagenesis of Acremonium chrysogenum deacetoxy/deacetylcephalosporin C synthase R308 site confirms its role in controlling substrate specificity. Biotechnol Lett 2010; 33:805-12. [DOI: 10.1007/s10529-010-0504-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 12/08/2010] [Indexed: 11/27/2022]
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33
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Pandey AS, Mulder DW, Ensign SA, Peters JW. Structural basis for carbon dioxide binding by 2-ketopropyl coenzyme M oxidoreductase/carboxylase. FEBS Lett 2010; 585:459-64. [DOI: 10.1016/j.febslet.2010.12.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/17/2010] [Accepted: 12/20/2010] [Indexed: 11/26/2022]
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Chapter 16. Enzymology of beta-lactam compounds with cephem structure produced by actinomycete. Methods Enzymol 2009; 458:401-29. [PMID: 19374992 DOI: 10.1016/s0076-6879(09)04816-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Cephamycins are beta-lactam antibiotics with a cephem structure produced by actinomycetes. They are synthesized by a pathway similar to that of cephalosporin C in filamentous fungi but the actinomycetes pathway contains additional enzymes for the formation of the alpha-aminoadipic acid (AAA) precursor and for the final steps specific to cephemycins. Most of the biochemical and genetic studies on cephemycins have been made on cephemycin C biosynthesis in the producer strains Streptomyces clavuligerus ATCC27064 and Amycolatopsis lactamdurans NRRL3802. Genes encoding cephamycin C biosynthetic enzymes are clustered in both actinomycetes. Ten enzymatic steps are involved in the formation of cephamycin C. The precursor alpha-AAA is formed by the sequential action of lysine-6-aminotransferase and piperideine-6-carboxylate dehydrogenase. Steps common to cephalosporin C biosynthesis include the formation of the tripeptide L-delta-alpha-aminoadipyl-L-cysteinyl-D-valine (ACV) by ACV synthetase, the cyclization of ACV to form isopenicillin N (IPN) by IPN synthase, the epimerization of IPN to penicillin N by isopenicillin N epimerase, the ring expansion of penicillin N to a six member cephem ring by deacetoxycephalosporin C synthase (DAOCS) and the hydroxylation at C-3' by deacetylcephalosporin C hydroxylase. However, in actinomycetes, the epimerization step is different from that in cephalosporin-producing fungi, and the expansion of the ring and its hydroxylation are performed by separate enzymes. Specific steps in cephamycin biosynthesis include the carbamoylation at C-3' by cephem carbamoyl transferase and the introduction of a methoxyl group at C-7 by the joint action of a C-7 cephem-hydroxylase and a methyltransferase. All the enzymes of the pathway have been purified almost to homogeneity and the DAOC synthase and 7-hydroxycephem-methyltransferase (CmcI) of S. clavuligerus have been crystallized giving insights into the mode of action of these enzymes. The cefE gene of S. clavuligerus, encoding DAOCS, has been extensively used to expand the penicillin ring in filamentous fungi in vivo using DNA recombinant technology.
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35
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Directed evolution and rational approaches to improving Streptomyces clavuligerus deacetoxycephalosporin C synthase for cephalosporin production. J Ind Microbiol Biotechnol 2009; 36:619-33. [DOI: 10.1007/s10295-009-0549-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 02/12/2009] [Indexed: 10/21/2022]
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36
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Structural and functional comparison of 2-His-1-carboxylate and 3-His metallocentres in non-haem iron(II)-dependent enzymes. Biochem Soc Trans 2009; 36:1180-6. [PMID: 19021520 DOI: 10.1042/bst0361180] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The canonical structural motif for co-ordination of non-haem ferrous iron in metal-dependent oxygenases is a facial triad of two histidine residues and one aspartate or glutamate residue. This so-called 2-His-1-carboxylate metallocentre is often accommodated in a double-stranded beta-helix fold with the iron-co-ordinating residues located in the rigid core structure of the protein. At the sequence level, the metal ligands are arranged in a HXD/E...H motif (where the distance between the conserved histidine residues is variable). Interestingly, cysteine dioxygenase, among a growing number of other iron(II) oxygenases, has the carboxylate residue replaced by another histidine. In the present review, we compare the properties of 3-His and 2-His-1-carboxylate sites based on current evidence from high-resolution crystal structures, spectroscopic characterization of the metal centres and results from mutagenesis studies. Although the overall conformation of the two metal sites is quite similar, the carboxylate residue seems to accommodate a slightly closer co-ordination distance than the counterpart histidine. The ability of the 2-His-1-carboxylate site to fit a site-directed substitution by an alternatively co-ordinating or non-co-ordinating residue with retention of metal-binding capacity and catalytic function varies among different enzymes. However, replacement by histidine disrupted the activity in the three iron(II) oxygenases examined so far.
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Meyer K, Bart SC. Tripodal carbene and aryloxide ligands for small-molecule activation at electron-rich uranium and transition metal centers. ADVANCES IN INORGANIC CHEMISTRY 2008. [DOI: 10.1016/s0898-8838(08)00001-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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38
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Flashman E, Bagg EAL, Chowdhury R, Mecinović J, Loenarz C, McDonough MA, Hewitson KS, Schofield CJ. Kinetic rationale for selectivity toward N- and C-terminal oxygen-dependent degradation domain substrates mediated by a loop region of hypoxia-inducible factor prolyl hydroxylases. J Biol Chem 2007; 283:3808-15. [PMID: 18063574 DOI: 10.1074/jbc.m707411200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hydroxylation of two conserved prolyl residues in the N- and C-terminal oxygen-dependent degradation domains (NODD and CODD) of the alpha-subunit of hypoxia-inducible factor (HIF) signals for its degradation via the ubiquitin-proteasome pathway. In human cells, three prolyl hydroxylases (PHDs 1-3) belonging to the Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenase family catalyze prolyl hydroxylation with differing selectivity for CODD and NODD. Sequence analysis of the catalytic domains of the PHDs in the light of crystal structures for PHD2, and results for other 2OG oxygenases, suggested that either the C-terminal region or a loop linking two beta-strands (beta2 and beta3 in human PHD2) are important in determining substrate selectivity. Mutation analyses on PHD2 revealed that the beta2beta3 loop is a major determinant in conferring selectivity for CODD over NODD peptides. A chimeric PHD in which the beta2beta3 loop of PHD2 was replaced with that of PHD3 displayed an almost complete selectivity for CODD (in competition experiments), as observed for wild-type PHD3. CODD was observed to bind much more tightly to this chimeric protein than the wild type PHD2 catalytic domain.
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Affiliation(s)
- Emily Flashman
- Chemistry Research Laboratory, Department of Chemistry and the Oxford Centre for Integrative Systems Biology, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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Purpero V, Moran GR. The diverse and pervasive chemistries of the alpha-keto acid dependent enzymes. J Biol Inorg Chem 2007; 12:587-601. [PMID: 17431691 DOI: 10.1007/s00775-007-0231-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 03/15/2007] [Indexed: 12/01/2022]
Abstract
The number of identified and confirmed alpha-keto acid dependent oxygenases is increasing rapidly. All of these enzymes have a relatively simple liganding arrangement for a single ferrous ion but collectively conduct a highly diverse set of chemistries. While hydroxylations and a variety of oxidation reactions have been most commonly observed, new reactions involving dealkylations, epimerizations and halogenations have recently been discovered. In this minireview we present what is known of the alpha-keto acid dependent enzymes and offer an argument that the chemistry that is unique to each enzyme occurs only after the production of a pivotal ferryl-oxo intermediate.
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Affiliation(s)
- Vincent Purpero
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer Street, Milwaukee, WI 53211-3029, USA
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40
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Cotelesage JJH, Puttick J, Goldie H, Rajabi B, Novakovski B, Delbaere LTJ. How does an enzyme recognize CO2? Int J Biochem Cell Biol 2007; 39:1204-10. [PMID: 17475535 DOI: 10.1016/j.biocel.2007.03.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 03/07/2007] [Accepted: 03/15/2007] [Indexed: 11/18/2022]
Abstract
Phosphoenolpyruvate carboxykinase (PCK) reversibly catalyzes the carboxylation of phosphoenolpyruvate to oxaloacetate. Carbon dioxide, and not bicarbonate ion, is the substrate utilized. Assays of the carboxylation reaction show that initial velocities are 7.6-fold higher when CO(2) is used instead of HCO(3)(-). Two Escherichia coli PCK-CO(2) crystal structures are presented here. The location of CO(2) is the same for both structures; however the orientation of CO(2) is significantly different, likely from the presence of a manganese ion in one of the structures. PCK and the other three known protein-CO(2) crystal structure complexes have been compared; all have CO(2) hydrogen bonding with a basic amino acid side chain (Arg65 or Lys213 in PCK), likely to polarize CO(2) to make the central carbon atom more electrophilic and thus more reactive. Kinetic studies found that the PCK mutant Arg65Gln increased the K(M) for substrates PEP and oxaloacetate but not for CO(2). The unchanged K(M) for CO(2) can be explained since the Arg65Gln mutant likely maintains a hydrogen bond to one of the oxygen atoms of carbon dioxide.
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Affiliation(s)
- Julien J H Cotelesage
- Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Sask., Canada
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41
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Hewitson KS, Liénard BMR, McDonough MA, Clifton IJ, Butler D, Soares AS, Oldham NJ, McNeill LA, Schofield CJ. Structural and mechanistic studies on the inhibition of the hypoxia-inducible transcription factor hydroxylases by tricarboxylic acid cycle intermediates. J Biol Chem 2006; 282:3293-301. [PMID: 17135241 DOI: 10.1074/jbc.m608337200] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In humans both the levels and activity of the alpha-subunit of the hypoxia-inducible transcription factor (HIF-alpha) are regulated by its post-translation hydroxylation as catalyzed by iron- and 2-oxoglutarate (2OG)-dependent prolyl and asparaginyl hydroxylases (PHD1-3 and factor-inhibiting HIF (FIH), respectively). One consequence of hypoxia is the accumulation of tricarboxylic acid cycle intermediates (TCAIs). In vitro assays were used to assess non-2OG TCAIs as inhibitors of purified PHD2 and FIH. Under the assay conditions, no significant FIH inhibition was observed by the TCAIs or pyruvate, but fumarate, succinate, and isocitrate inhibited PHD2. Mass spectrometric analyses under nondenaturing conditions were used to investigate the binding of TCAIs to PHD2 and supported the solution studies. X-ray crystal structures of FIH in complex with Fe(II) and fumarate or succinate revealed similar binding modes for each in the 2OG co-substrate binding site. The in vitro results suggest that the cellular inhibition of PHD2, but probably not FIH, by fumarate and succinate may play a role in the Warburg effect providing that appropriate relative concentrations of the components are achieved under physiological conditions.
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Affiliation(s)
- Kirsty S Hewitson
- Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom.
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42
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Neidig ML, Decker A, Choroba OW, Huang F, Kavana M, Moran GR, Spencer JB, Solomon EI. Spectroscopic and electronic structure studies of aromatic electrophilic attack and hydrogen-atom abstraction by non-heme iron enzymes. Proc Natl Acad Sci U S A 2006; 103:12966-73. [PMID: 16920789 PMCID: PMC1559736 DOI: 10.1073/pnas.0605067103] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
(4-Hydroxy)mandelate synthase (HmaS) and (4-hydroxyphenyl)pyruvate dioxygenase (HPPD) are two alpha-keto acid dependent mononuclear non-heme iron enzymes that use the same substrate, (4-hydroxyphenyl)pyruvate, but exhibit two different general reactivities. HmaS performs hydrogen-atom abstraction to yield benzylic hydroxylated product (S)-(4-hydroxy)mandelate, whereas HPPD utilizes an electrophilic attack mechanism that results in aromatic hydroxylated product homogentisate. These enzymes provide a unique opportunity to directly evaluate the similarities and differences in the reaction pathways used for these two reactivities. An Fe(II) methodology using CD, magnetic CD, and variable-temperature, variable-field magnetic CD spectroscopies was applied to HmaS and compared with that for HPPD to evaluate the factors that affect substrate interactions at the active site and to correlate these to the different reactivities exhibited by HmaS and HPPD to the same substrate. Combined with density functional theory calculations, we found that HmaS and HPPD have similar substrate-bound complexes and that the role of the protein pocket in determining the different reactivities exhibited by these enzymes (hydrogen-atom abstraction vs. aromatic electrophilic attack) is to properly orient the substrate, allowing for ligand field geometric changes along the reaction coordinate. Elongation of the Fe(IV) O bond in the transition state leads to dominant Fe(III) O(*-) character, which significantly contributes to the reactivity with either the aromatic pi-system or the C H sigma-bond.
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Affiliation(s)
| | - Andrea Decker
- Department of Chemistry, Stanford University, Stanford, CA 94306
| | - Oliver W. Choroba
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom; and
| | - Fanglu Huang
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom; and
| | - Michael Kavana
- Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee, WI 53211
| | - Graham R. Moran
- Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee, WI 53211
| | - Jonathan B. Spencer
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom; and
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94306
- To whom correspondence should be addressed: E-mail:
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McDonough MA, Li V, Flashman E, Chowdhury R, Mohr C, Liénard BMR, Zondlo J, Oldham NJ, Clifton IJ, Lewis J, McNeill LA, Kurzeja RJM, Hewitson KS, Yang E, Jordan S, Syed RS, Schofield CJ. Cellular oxygen sensing: Crystal structure of hypoxia-inducible factor prolyl hydroxylase (PHD2). Proc Natl Acad Sci U S A 2006; 103:9814-9. [PMID: 16782814 PMCID: PMC1502536 DOI: 10.1073/pnas.0601283103] [Citation(s) in RCA: 278] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Indexed: 11/18/2022] Open
Abstract
Cellular and physiological responses to changes in dioxygen levels in metazoans are mediated via the posttranslational oxidation of hypoxia-inducible transcription factor (HIF). Hydroxylation of conserved prolyl residues in the HIF-alpha subunit, catalyzed by HIF prolyl-hydroxylases (PHDs), signals for its proteasomal degradation. The requirement of the PHDs for dioxygen links changes in dioxygen levels with the transcriptional regulation of the gene array that enables the cellular response to chronic hypoxia; the PHDs thus act as an oxygen-sensing component of the HIF system, and their inhibition mimics the hypoxic response. We describe crystal structures of the catalytic domain of human PHD2, an important prolyl-4-hydroxylase in the human hypoxic response in normal cells, in complex with Fe(II) and an inhibitor to 1.7 A resolution. PHD2 crystallizes as a homotrimer and contains a double-stranded beta-helix core fold common to the Fe(II) and 2-oxoglutarate-dependant dioxygenase family, the residues of which are well conserved in the three human PHD enzymes (PHD 1-3). The structure provides insights into the hypoxic response, helps to rationalize a clinically observed mutation leading to familial erythrocytosis, and will aid in the design of PHD selective inhibitors for the treatment of anemia and ischemic disease.
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Affiliation(s)
- Michael A. McDonough
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Vivian Li
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Emily Flashman
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Rasheduzzaman Chowdhury
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Christopher Mohr
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Benoît M. R. Liénard
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - James Zondlo
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Neil J. Oldham
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Ian J. Clifton
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Jeffrey Lewis
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Luke A. McNeill
- ReOx Ltd., Magdalen Center, Oxford Science Park, Oxford OX4 4GA, United Kingdom; and
| | | | - Kirsty S. Hewitson
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
- ReOx Ltd., Magdalen Center, Oxford Science Park, Oxford OX4 4GA, United Kingdom; and
| | - Evelyn Yang
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Steven Jordan
- Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320-1789
| | - Rashid S. Syed
- ReOx Ltd., Magdalen Center, Oxford Science Park, Oxford OX4 4GA, United Kingdom; and
| | - Christopher J. Schofield
- *Oxford Centre for Molecular Sciences and Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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44
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Clifton IJ, McDonough MA, Ehrismann D, Kershaw NJ, Granatino N, Schofield CJ. Structural studies on 2-oxoglutarate oxygenases and related double-stranded β-helix fold proteins. J Inorg Biochem 2006; 100:644-69. [PMID: 16513174 DOI: 10.1016/j.jinorgbio.2006.01.024] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 01/12/2006] [Accepted: 01/12/2006] [Indexed: 01/09/2023]
Abstract
Mononuclear non-heme ferrous iron dependent oxygenases and oxidases constitute an extended enzyme family that catalyze a wide range of oxidation reactions. The largest known sub-group employs 2-oxoglutarate as a cosubstrate and catalysis by these and closely related enzymes is proposed to proceed via a ferryl intermediate coordinated to the active site via a conserved HXD/E...H motif. Crystallographic studies on the 2-oxoglutarate oxygenases and related enzymes have revealed a common double-stranded beta-helix core fold that supports the residues coordinating the iron. This fold is common to proteins of the cupin and the JmjC transcription factor families. The crystallographic studies on 2-oxoglutarate oxygenases and closely related enzymes are reviewed and compared with other metallo-enzymes/related proteins containing a double-stranded beta-helix fold. Proposals regarding the suitability of the active sites and folds of the 2-oxoglutarate oxygenases to catalyze reactions involving reactive oxidizing species are described.
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Affiliation(s)
- Ian J Clifton
- The Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, Oxon OX1 3TA, UK
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45
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Mishina Y, He C. Oxidative dealkylation DNA repair mediated by the mononuclear non-heme iron AlkB proteins. J Inorg Biochem 2006; 100:670-8. [PMID: 16469386 PMCID: PMC2386269 DOI: 10.1016/j.jinorgbio.2005.12.018] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 12/13/2005] [Indexed: 11/19/2022]
Abstract
DNA can be damaged by various intracellular and environmental alkylating agents to produce alkylation base lesions. These base damages, if not repaired promptly, may cause genetic changes that lead to diseases such as cancer. Recently, it was discovered that some of the alkylation DNA base damage can be directly removed by a family of proteins called the AlkB proteins that utilize a mononuclear non-heme iron(II) and alpha-ketoglutarate as cofactor and cosubstrate. These proteins activate dioxygen and perform an unprecedented oxidative dealkylation of the alkyl adducts on DNA heteroatoms. This review summarizes the discovery of this activity and the recent research advances in studying this unique DNA repair pathway. The focus is placed on the chemical mechanism and function of these proteins.
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Affiliation(s)
| | - Chuan He
- Corresponding author. Tel.: +1 773 702 5061; fax: +1 773 702 0805. E-mail address: (C. He)
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46
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Wei CL, Yang YB, Deng CH, Liu WC, Hsu JS, Lin YC, Liaw SH, Tsai YC. Directed evolution of Streptomyces clavuligerus deacetoxycephalosporin C synthase for enhancement of penicillin G expansion. Appl Environ Microbiol 2006; 71:8873-80. [PMID: 16332884 PMCID: PMC1317366 DOI: 10.1128/aem.71.12.8873-8880.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The deacetoxycephalosporin C synthase from Streptomyces clavuligerus was directly modified for enhancement of penicillin G expansion into phenylacetyl-7-aminodeacetoxycephalosporanic acid, an important intermediate in the industrial manufacture of cephalosporin antibiotics. Nine new mutants, mutants M73T, T91A, A106T, C155Y, Y184H, M188V, M188I, H244Q, and L277Q with 1.4- to 5.7-fold increases in the kcat/Km ratio, were obtained by screening 6,364 clones after error-prone PCR-based random mutagenesis. Subsequently, DNA shuffling was carried out to screen possible combinations of substitutions, including previous point mutations. One quaternary mutant, the C155Y/Y184H/V275I/C281Y mutant, which had a kcat/Km ratio that was 41-fold higher was found after 10,572 clones were assayed. The distinct mutants obtained using different mutagenesis methods demonstrated the complementarity of the techniques. Interestingly, most of the mutated residues that result in enhanced activities are located within or near the unique small barrel subdomain, suggesting that manipulation of this subdomain may be a constructive strategy for improvement of penicillin expansion. Several mutations had very distinct effects on expansion of penicillins N and G, perhaps due to different penicillin-interacting modes within the enzyme. Thus, the present study provided not only promising enzymes for cephalosporin biosynthesis but also a large number of mutants, which provided new insights into the structure-function relationship of the protein that should lead to further rational engineering.
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Affiliation(s)
- Chia-Li Wei
- Institute of Biochemistry, National Yang-Ming University, 155, Sec. 2, Li-Nong St., Pei-Tou, Taipei 11221, Taiwan
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47
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Affiliation(s)
- Yukiko Mishina
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637
| | - Erica M. Duguid
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637
| | - Chuan He
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637
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Castro-Rodríguez I, Meyer K. Small molecule activation at uranium coordination complexes: control of reactivity via molecular architecture. Chem Commun (Camb) 2006:1353-68. [PMID: 16550268 DOI: 10.1039/b513755c] [Citation(s) in RCA: 205] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron-rich uranium coordination complexes display a pronounced reactivity toward small molecules. In this Feature article, the exciting chemistry of trivalent uranium ions coordinated to classic Werner-type ligand environments is reviewed. Three fundamentally important reactions of the [(((R)ArO)3tacn)U]-system are presented that result in alkane coordination, CO/CO2 activation, and nitrogen atom-transfer chemistry.
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Affiliation(s)
- Ingrid Castro-Rodríguez
- Department of Chemistry, University of California, Latimer Hall, Berkeley, California 94720, USA.
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Bollinger JM, Price JC, Hoffart LM, Barr EW, Krebs C. Mechanism of Taurine: α‐Ketoglutarate Dioxygenase (TauD) from
Escherichia coli. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500476] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- J. Martin Bollinger
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA, Fax: +1‐814‐863‐7024
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - John C. Price
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA, Fax: +1‐814‐863‐7024
| | - Lee M. Hoffart
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA, Fax: +1‐814‐863‐7024
| | - Eric W. Barr
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA, Fax: +1‐814‐863‐7024
| | - Carsten Krebs
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA, Fax: +1‐814‐863‐7024
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
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50
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Wu XB, Fan KQ, Wang QH, Yang KQ. C-terminus mutations of Acremonium chrysogenum deacetoxy/deacetylcephalosporin C synthase with improved activity toward penicillin analogs. FEMS Microbiol Lett 2005; 246:103-10. [PMID: 15869968 DOI: 10.1016/j.femsle.2005.03.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Revised: 03/16/2005] [Accepted: 03/26/2005] [Indexed: 10/25/2022] Open
Abstract
Deacetoxy/deacetylcephalosporin C synthase (acDAOC/DACS) from Acremonium chrysogenum is a bifunctional enzyme that catalyzes both the ring-expansion of penicillin N to deacetoxycephalosporin C (DAOC) and the hydroxylation of the latter to deacetylcephalosporin C (DAC). Three residues N305, R307 and R308 located in close proximity to the C-terminus of acDAOC/DACS were each mutated to leucine. The N305L and R308L mutant acDAOC/DACSs showed significant improvement in their ability to convert penicillin analogs. R308 was identified for the first time as a critical residue for DAOC/DACS activity. Kinetic analyses of purified R308L enzyme indicated its improved catalytic efficiency is due to combined improvements of K(m) and k(cat). Comparative modeling of acDAOC/DACS supports the involvement of R308 in the formation of substrate-binding pocket.
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Affiliation(s)
- Xiao-Bin Wu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, PR China
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