1
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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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2
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Iacovelli R, Bovenberg RAL, Driessen AJM. Nonribosomal peptide synthetases and their biotechnological potential in Penicillium rubens. J Ind Microbiol Biotechnol 2021; 48:6324005. [PMID: 34279620 PMCID: PMC8788816 DOI: 10.1093/jimb/kuab045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/12/2021] [Indexed: 01/23/2023]
Abstract
Nonribosomal peptide synthetases (NRPS) are large multimodular enzymes that synthesize a diverse variety of peptides. Many of these are currently used as pharmaceuticals, thanks to their activity as antimicrobials (penicillin, vancomycin, daptomycin, echinocandin), immunosuppressant (cyclosporin) and anticancer compounds (bleomycin). Because of their biotechnological potential, NRPSs have been extensively studied in the past decades. In this review, we provide an overview of the main structural and functional features of these enzymes, and we consider the challenges and prospects of engineering NRPSs for the synthesis of novel compounds. Furthermore, we discuss secondary metabolism and NRP synthesis in the filamentous fungus Penicillium rubens and examine its potential for the production of novel and modified β-lactam antibiotics.
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Affiliation(s)
- Riccardo Iacovelli
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Roel A L Bovenberg
- Synthetic Biology and Cell Engineering, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands.,DSM Biotechnology Centre, 2613 AX Delft, The Netherlands
| | - Arnold J M Driessen
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
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3
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Chapman NC, Rutledge PJ. Isopenicillin N Synthase: Crystallographic Studies. Chembiochem 2021; 22:1687-1705. [PMID: 33415840 DOI: 10.1002/cbic.202000743] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/01/2021] [Indexed: 02/02/2023]
Abstract
Isopenicillin N synthase (IPNS) is a non-heme iron oxidase (NHIO) that catalyses the cyclisation of tripeptide δ-(l-α-aminoadipoyl)-l-cysteinyl-d-valine (ACV) to bicyclic isopenicillin N (IPN). Over the last 25 years, crystallography has shed considerable light on the mechanism of IPNS catalysis. The first crystal structure, for apo-IPNS with Mn bound in place of Fe at the active site, reported in 1995, was also the first structure for a member of the wider NHIO family. This was followed by the anaerobic enzyme-substrate complex IPNS-Fe-ACV (1997), this complex plus nitric oxide as a surrogate for co-substrate dioxygen (1997), and an enzyme product complex (1999). Since then, crystallography has been used to probe many aspects of the IPNS reaction mechanism, by crystallising the protein with a diversity of substrate analogues and triggering the oxidative reaction by using elevated oxygen pressures to force the gaseous co-substrate throughout protein crystals and maximise synchronicity of turnover in crystallo. In this way, X-ray structures have been elucidated for a range of complexes closely related to and/or directly derived from key intermediates in the catalytic cycle, thereby answering numerous mechanistic questions that had arisen from solution-phase experiments, and posing many new ones. The results of these crystallographic studies have, in turn, informed computational experiments that have brought further insight. These combined crystallographic and computational investigations augment and extend the results of earlier spectroscopic analyses and solution phase studies of IPNS turnover, to enrich our understanding of this important protein and the wider NHIO enzyme family.
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Affiliation(s)
- Nicole C Chapman
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Peter J Rutledge
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
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4
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Wojdyla Z, Borowski T. Enzyme Multifunctionality by Control of Substrate Positioning Within the Catalytic Cycle—A QM/MM Study of Clavaminic Acid Synthase. Chemistry 2020; 27:2196-2211. [DOI: 10.1002/chem.202004426] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Zuzanna Wojdyla
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences Niezapominajek 8 30239 Krakow Poland
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences Niezapominajek 8 30239 Krakow Poland
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5
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Rabe P, Beale JH, Butryn A, Aller P, Dirr A, Lang PA, Axford DN, Carr SB, Leissing TM, McDonough MA, Davy B, Ebrahim A, Orlans J, Storm SLS, Orville AM, Schofield CJ, Owen RL. Anaerobic fixed-target serial crystallography. IUCRJ 2020; 7:901-912. [PMID: 32939282 PMCID: PMC7467159 DOI: 10.1107/s2052252520010374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/27/2020] [Indexed: 05/04/2023]
Abstract
Cryogenic X-ray diffraction is a powerful tool for crystallographic studies on enzymes including oxygenases and oxidases. Amongst the benefits that cryo-conditions (usually employing a nitro-gen cryo-stream at 100 K) enable, is data collection of di-oxy-gen-sensitive samples. Although not strictly anaerobic, at low temperatures the vitreous ice conditions severely restrict O2 diffusion into and/or through the protein crystal. Cryo-conditions limit chemical reactivity, including reactions that require significant conformational changes. By contrast, data collection at room temperature imposes fewer restrictions on diffusion and reactivity; room-temperature serial methods are thus becoming common at synchrotrons and XFELs. However, maintaining an anaerobic environment for di-oxy-gen-dependent enzymes has not been explored for serial room-temperature data collection at synchrotron light sources. This work describes a methodology that employs an adaptation of the 'sheet-on-sheet' sample mount, which is suitable for the low-dose room-temperature data collection of anaerobic samples at synchrotron light sources. The method is characterized by easy sample preparation in an anaerobic glovebox, gentle handling of crystals, low sample consumption and preservation of a localized anaerobic environment over the timescale of the experiment (<5 min). The utility of the method is highlighted by studies with three X-ray-radiation-sensitive Fe(II)-containing model enzymes: the 2-oxoglutarate-dependent l-arginine hy-droxy-lase VioC and the DNA repair enzyme AlkB, as well as the oxidase isopenicillin N synthase (IPNS), which is involved in the biosynthesis of all penicillin and cephalosporin antibiotics.
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Affiliation(s)
- Patrick Rabe
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - John H. Beale
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Agata Butryn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Pierre Aller
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Anna Dirr
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Pauline A. Lang
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Danny N. Axford
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Stephen B. Carr
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot Oxfordshire OX11 0FA, United Kingdom
| | - Thomas M. Leissing
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Michael A. McDonough
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Bradley Davy
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Ali Ebrahim
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom
| | - Julien Orlans
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- UMR0203, Biologie Fonctionnelle, Insectes et Interactions, Institut National des Sciences Appliquées de Lyon, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, University of Lyon, Villeurbanne F-69621, France
| | - Selina L. S. Storm
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Allen M. Orville
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Christopher J. Schofield
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Robin L. Owen
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
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6
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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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7
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McNeill LA, Brown TJN, Sami M, Clifton IJ, Burzlaff NI, Claridge TDW, Adlington RM, Baldwin JE, Rutledge PJ, Schofield CJ. Terminally Truncated Isopenicillin N Synthase Generates a Dithioester Product: Evidence for a Thioaldehyde Intermediate during Catalysis and a New Mode of Reaction for Non-Heme Iron Oxidases. Chemistry 2017; 23:12815-12824. [PMID: 28703303 PMCID: PMC5637899 DOI: 10.1002/chem.201701592] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Indexed: 11/25/2022]
Abstract
Isopenicillin N synthase (IPNS) catalyses the four‐electron oxidation of a tripeptide, l‐δ‐(α‐aminoadipoyl)‐l‐cysteinyl‐d‐valine (ACV), to give isopenicillin N (IPN), the first‐formed β‐lactam in penicillin and cephalosporin biosynthesis. IPNS catalysis is dependent upon an iron(II) cofactor and oxygen as a co‐substrate. In the absence of substrate, the carbonyl oxygen of the side‐chain amide of the penultimate residue, Gln330, co‐ordinates to the active‐site metal iron. Substrate binding ablates the interaction between Gln330 and the metal, triggering rearrangement of seven C‐terminal residues, which move to take up a conformation that extends the final α‐helix and encloses ACV in the active site. Mutagenesis studies are reported, which probe the role of the C‐terminal and other aspects of the substrate binding pocket in IPNS. The hydrophobic nature of amino acid side‐chains around the ACV binding pocket is important in catalysis. Deletion of seven C‐terminal residues exposes the active site and leads to formation of a new type of thiol oxidation product. The isolated product is shown by LC‐MS and NMR analyses to be the ene‐thiol tautomer of a dithioester, made up from two molecules of ACV linked between the thiol sulfur of one tripeptide and the oxidised cysteinyl β‐carbon of the other. A mechanism for its formation is proposed, supported by an X‐ray crystal structure, which shows the substrate ACV bound at the active site, its cysteinyl β‐carbon exposed to attack by a second molecule of substrate, adjacent. Formation of this product constitutes a new mode of reaction for IPNS and non‐heme iron oxidases in general.
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Affiliation(s)
- Luke A McNeill
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.,Present Address: Oxford Nanopore Technologies, Oxford Science Park, OX4 4GA, UK
| | - Toby J N Brown
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.,Present Address: The Brattle Group, Level 15 5 Martin Place, Sydney, NSW, 2000, Australia
| | - Malkit Sami
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.,Present Address: Immunocore Limited, 101 Park Drive, Milton Park, Abingdon, OX14 4RY, UK
| | - Ian J Clifton
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
| | - Nicolai I Burzlaff
- Department of Chemistry and Pharmacy, University of Erlangen-Nuremberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Timothy D W Claridge
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
| | - Robert M Adlington
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
| | - Jack E Baldwin
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
| | - Peter J Rutledge
- School of Chemistry, The University of Sydney, NSW, 2006, Australia
| | - Christopher J Schofield
- Oxford Centre for Molecular Sciences and the Department of Chemistry, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
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8
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Clifton IJ, Ge W, Adlington RM, Baldwin JE, Rutledge PJ. The crystal structure of an isopenicillin N synthase complex with an ethereal substrate analogue reveals water in the oxygen binding site. FEBS Lett 2013; 587:2705-9. [DOI: 10.1016/j.febslet.2013.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 07/04/2013] [Accepted: 07/04/2013] [Indexed: 10/26/2022]
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9
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Daruzzaman A, Clifton IJ, Adlington RM, Baldwin JE, Rutledge PJ. The Interaction of Isopenicillin N Synthase with Homologated Substrate Analogues δ-(L-α-Aminoadipoyl)-L-homocysteinyl-D-Xaa Characterised by Protein Crystallography. Chembiochem 2013; 14:599-606. [DOI: 10.1002/cbic.201200728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Indexed: 11/11/2022]
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10
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Daruzzaman A, Clifton IJ, Adlington RM, Baldwin JE, Rutledge PJ. The crystal structure of isopenicillin N synthase with a dipeptide substrate analogue. Arch Biochem Biophys 2013; 530:48-53. [DOI: 10.1016/j.abb.2012.12.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/07/2012] [Accepted: 12/09/2012] [Indexed: 11/29/2022]
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11
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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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12
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Abstract
The S-oxygenation of cysteine with dioxygen to give cysteine sulfinic acid occurs at the non-heme iron active site of cysteine dioxygenase. Similar S-oxygenation events occur in other non-heme iron enzymes, including nitrile hydratase and isopenicillin N synthase, and these enzymes have inspired the development of a class of [N(x)S(y)]-Fe model complexes. Certain members of this class have provided some intriguing examples of S-oxygenation, and this article summarizes these results, focusing on the non-heme iron(II/III)-thiolate model complexes that are known to react with O(2) or other O-atom transfer oxidants to yield sulfur oxygenates. Key aspects of the synthesis, structure, and reactivity of these systems are presented, along with any mechanistic information available on the oxygenation reactions. A number of iron(III)-thiolate complexes react with O(2) to give S-oxygenates, and the degree to which the thiolate sulfur donors are oxidized varies among the different complexes, depending upon the nature of the ligand, metal geometry, and spin state. The first examples of iron(II)-thiolate complexes that react with O(2) to give selective S-oxygenation are just emerging. Mechanistic information on these transformations is limited, with isotope labeling studies providing much of the current mechanistic data. The many questions that remain unanswered for both models and enzymes provide strong motivation for future work in this area.
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Affiliation(s)
- Alison C. McQuilken
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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13
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Clifton IJ, Ge W, Adlington RM, Baldwin JE, Rutledge PJ. The crystal structure of isopenicillin N synthase with δ-(l-α-aminoadipoyl)-l-cysteinyl-d-methionine reveals thioether coordination to iron. Arch Biochem Biophys 2011; 516:103-7. [DOI: 10.1016/j.abb.2011.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 09/28/2011] [Accepted: 09/30/2011] [Indexed: 12/01/2022]
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14
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Clifton IJ, Ge W, Adlington RM, Baldwin JE, Rutledge PJ. Isopenicillin N Synthase Binds δ-(L-α-Aminoadipoyl)-L-Cysteinyl-D-Thia-allo-Isoleucine through both Sulfur Atoms. Chembiochem 2011; 12:1881-5. [DOI: 10.1002/cbic.201100149] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Indexed: 11/08/2022]
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15
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Ge W, Clifton IJ, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ. Crystallographic studies on the binding of selectively deuterated LLD- and LLL-substrate epimers by isopenicillin N synthase. Biochem Biophys Res Commun 2010; 398:659-64. [DOI: 10.1016/j.bbrc.2010.06.129] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 06/30/2010] [Indexed: 10/19/2022]
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16
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Brown-Marshall CD, Diebold AR, Solomon EI. Reaction coordinate of isopenicillin N synthase: oxidase versus oxygenase activity. Biochemistry 2010; 49:1176-82. [PMID: 20078029 DOI: 10.1021/bi901772w] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Isopenicillin N synthase (IPNS) can have both oxidase and oxygenase activity depending on the substrate. For the native substrate, ACV, oxidase activity exists; however, for the substrate analogue ACOV, which lacks an amide nitrogen, IPNS exhibits oxygenase activity. The potential energy surfaces for the O-O bond elongation and cleavage were calculated for three different reactions: homolytic cleavage via traditional Fenton chemistry, heterolytic cleavage, and nucleophilic attack. These surfaces show that the hydroperoxide-ferrous intermediate, formed by O(2)-activated H atom abstraction from the substrate, can exploit different reaction pathways and that interactions with the substrate govern the pathway. The hydrogen bonds from hydroperoxide to the amide nitrogen of ACV polarize the sigma* orbital of the peroxide toward the proximal oxygen, facilitating heterolytic cleavage. For the substrate analogue ACOV, this hydrogen bond is no longer present, leading to nucleophilic attack on the substrate intermediate C-S bond. After cleavage of the hydroperoxide, the two reaction pathways proceed with minimal barriers, resulting in the closure of the beta-lactam ring for the oxidase activity (ACV) or formation of the thiocarboxylate for oxygenase activity (ACOV).
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17
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Ge W, Clifton IJ, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ. The crystal structure of anlll-configured depsipeptide substrate analogue bound to isopenicillin N synthase. Org Biomol Chem 2010; 8:122-7. [DOI: 10.1039/b910170e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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18
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Ge W, Clifton IJ, Howard-Jones AR, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ. Structural Studies on the Reaction of Isopenicillin N Synthase with a Sterically Demanding Depsipeptide Substrate Analogue. Chembiochem 2009; 10:2025-31. [DOI: 10.1002/cbic.200900080] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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19
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Stewart AC, Clifton IJ, Adlington RM, Baldwin JE, Rutledge PJ. A Cyclobutanone Analogue Mimics Penicillin in Binding to Isopenicillin N Synthase. Chembiochem 2007; 8:2003-7. [PMID: 17907118 DOI: 10.1002/cbic.200700176] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A carbocyclic analogue of the beta-lactam antibiotic isopenicillin N (IPN) has been synthesised and cocrystallised with isopenicillin N synthase (IPNS), the central enzyme in the biosynthesis of penicillin antibiotics. The crystal structure of the IPNS-cyclobutanone complex reveals an active site environment similar to that seen in the enzyme-product complex generated by turnover of the natural substrate within the crystalline protein. The IPNS-cyclobutanone structure demonstrates that the product analogue is tethered to the protein by hydrogen bonding and salt bridge interactions with its carboxylate groups, as seen previously for the natural substrate and product. Furthermore, the successful cocrystallisation of this analogue with IPNS provides firm structural evidence for the utility of such cyclobutanone derivatives as hydrolytically stable analogues of bicyclic beta-lactams.
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Affiliation(s)
- Amanda C Stewart
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK
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20
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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: 339] [Impact Index Per Article: 18.8] [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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21
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Daruzzaman A, Clifton IJ, Adlington RM, Baldwin JE, Rutledge PJ. Unexpected Oxidation of a Depsipeptide Substrate Analogue in Crystalline Isopenicillin N Synthase. Chembiochem 2006; 7:351-8. [PMID: 16444759 DOI: 10.1002/cbic.200500282] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Isopenicillin N synthase (IPNS) is a non-heme iron(ii)-dependent oxidase that is central to penicillin biosynthesis. Herein, we report mechanistic studies of the IPNS reaction in the crystalline state, using the substrate analogue delta-(L-alpha-aminoadipoyl)-(3R)-methyl-L-cysteine D-alpha-hydroxyisovaleryl ester (AmCOV) to probe the early stages of the catalytic cycle. The X-ray crystal structure of the anaerobic IPNS:Fe(II):AmCOV complex was solved to 1.40 A resolution, and it reveals several subtle differences in the active site relative to the complex of the enzyme with its natural substrate. The crystalline IPNS:Fe(II):AmCOV complex was then exposed to oxygen gas at high pressure; this brought about reaction to give what appears to be a hydroxymethyl/ene-thiol product. A mechanism for this reaction is proposed. These results offer further insight into the delicate interplay of steric and electronic effects in the IPNS active site and the mechanistic intricacies of this remarkable enzyme.
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Affiliation(s)
- Adam Daruzzaman
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK
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Howard-Jones AR, Rutledge PJ, Clifton IJ, Adlington RM, Baldwin JE. Unique binding of a non-natural l,l,l-substrate by isopenicillin N synthase. Biochem Biophys Res Commun 2005; 336:702-8. [PMID: 16143309 DOI: 10.1016/j.bbrc.2005.08.155] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Accepted: 08/08/2005] [Indexed: 11/26/2022]
Abstract
Isopenicillin N synthase (IPNS) is a non-haem iron oxidase that catalyses the formation of isopenicillin N from the tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine. In this report, we describe the crystal structure of the enzyme with a non-natural L,L,L-tripeptide substrate, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-L-3,3,3,3',3',3'-hexafluorovaline. This structure reveals a strong binding interaction of the tripeptide within the active site and a unique conformation for the non-natural L,L,L-diastereomer. Taken together, these findings provide a possible rationale for the previously observed inhibitory effects of L,L,L-tripeptide substrates on IPNS activity.
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Grummitt A, Rutledge P, Clifton I, Baldwin J. Active-site-mediated elimination of hydrogen fluoride from a fluorinated substrate analogue by isopenicillin N synthase. Biochem J 2005; 382:659-66. [PMID: 15175003 PMCID: PMC1133823 DOI: 10.1042/bj20040529] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 06/01/2004] [Accepted: 06/03/2004] [Indexed: 11/17/2022]
Abstract
Isopenicillin N synthase (IPNS) is a non-haem iron oxidase that catalyses the formation of bicyclic isopenicillin N from delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV). In this study we report a novel activity for the iron of the IPNS active site, which behaves as a Lewis acid to catalyse the elimination of HF from the fluorinated substrate analogue, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-beta-fluorovaline (ACbetaFV). X-Ray crystallographic studies of IPNS crystals grown anaerobically with ACbetaFV reveal that the valinyl beta-fluorine is missing from the active site region, and suggest the presence of the unsaturated tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-isodehydrovaline in place of substrate ACbetaFV. (19)F NMR studies confirm the release of fluoride from ACbetaFV in the presence of the active IPNS enzyme. These results suggest a new mode of reactivity for the IPNS iron centre, a mechanism of action that has not previously been reported for any of the iron oxidase enzymes.
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Affiliation(s)
- Annaleise R. Grummitt
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Peter J. Rutledge
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Ian J. Clifton
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Jack E. Baldwin
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
- To whom correspondence should be addressed (email )
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