1
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Serapian S, Crosby J, Crump MP, van der Kamp MW. Path to Actinorhodin: Regio- and Stereoselective Ketone Reduction by a Type II Polyketide Ketoreductase Revealed in Atomistic Detail. JACS Au 2022; 2:972-984. [PMID: 35557750 PMCID: PMC9088766 DOI: 10.1021/jacsau.2c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 06/15/2023]
Abstract
In type II polyketide synthases (PKSs), which typically biosynthesize several antibiotic and antitumor compounds, the substrate is a growing polyketide chain, shuttled between individual PKS enzymes, while covalently tethered to an acyl carrier protein (ACP): this requires the ACP interacting with a series of different enzymes in succession. During biosynthesis of the antibiotic actinorhodin, produced by Streptomyces coelicolor, one such key binding event is between an ACP carrying a 16-carbon octaketide chain (actACP) and a ketoreductase (actKR). Once the octaketide is bound inside actKR, it is likely cyclized between C7 and C12 and regioselective reduction of the ketone at C9 occurs: how these elegant chemical and conformational changes are controlled is not yet known. Here, we perform protein-protein docking, protein NMR, and extensive molecular dynamics simulations to reveal a probable mode of association between actACP and actKR; we obtain and analyze a detailed model of the C7-C12-cyclized octaketide within the actKR active site; and we confirm this model through multiscale (QM/MM) reaction simulations of the key ketoreduction step. Molecular dynamics simulations show that the most thermodynamically stable cyclized octaketide isomer (7R,12R) also gives rise to the most reaction competent conformations for ketoreduction. Subsequent reaction simulations show that ketoreduction is stereoselective as well as regioselective, resulting in an S-alcohol. Our simulations further indicate several conserved residues that may be involved in selectivity of C7-12 cyclization and C9 ketoreduction. Detailed insights obtained on ACP-based substrate presentation in type II PKSs can help design ACP-ketoreductase systems with altered regio- or stereoselectivity.
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Affiliation(s)
- Stefano
A. Serapian
- School
of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
| | - John Crosby
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Matthew P. Crump
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Marc W. van der Kamp
- School
of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
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2
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Jin Y, Niu CY, Brown KW, Li ZH, Hua H, Anthony AK, Barney J, Charity RJ, Crosby J, Dell'Aquila D, Elson JM, Estee J, Ghazali M, Jhang G, Li JG, Lynch WG, Michel N, Sobotka LG, Sweany S, Teh FCE, Thomas A, Tsang CY, Tsang MB, Wang SM, Wu HY, Yuan CX, Zhu K. First Observation of the Four-Proton Unbound Nucleus ^{18}Mg. Phys Rev Lett 2021; 127:262502. [PMID: 35029460 DOI: 10.1103/physrevlett.127.262502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/18/2021] [Accepted: 11/16/2021] [Indexed: 06/14/2023]
Abstract
^{18}Mg was observed, for the first time, by the invariant-mass reconstruction of ^{14}O+4p events. The ground-state decay energy and width are E_{T}=4.865(34) MeV and Γ=115(100) keV, respectively. The observed momentum correlations between the five particles are consistent with two sequential steps of prompt 2p decay passing through the ground state of ^{16}Ne. The invariant-mass spectrum also provides evidence for an excited state at an excitation energy of 1.84(14) MeV, which is likely the first excited 2^{+} state. As this energy exceeds that for the 2^{+} state in ^{20}Mg, this observation provides an argument for the demise of the N=8 shell closure in nuclei far from stability. However, in open systems this classical argument for shell strength is compromised by Thomas-Ehrman shifts.
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Affiliation(s)
- Y Jin
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - C Y Niu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K W Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z H Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - H Hua
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - A K Anthony
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Barney
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - R J Charity
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Crosby
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Dell'Aquila
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J M Elson
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Estee
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Ghazali
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Jhang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - W G Lynch
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Michel
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - L G Sobotka
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - S Sweany
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - F C E Teh
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Thomas
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - C Y Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M B Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - S M Wang
- Institute of Modern Physics, Fudan University, Shanghai 200433, China
- FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - H Y Wu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - C X Yuan
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China
| | - K Zhu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
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3
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MacKenna A, Schwarze JE, Crosby J, Zegers-Hochschild F. Factors associated with embryo splitting and clinical outcome of monozygotic twins in pregnancies after IVF and ICSI. Hum Reprod Open 2020; 2020:hoaa024. [PMID: 32432173 PMCID: PMC7225016 DOI: 10.1093/hropen/hoaa024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 03/18/2020] [Indexed: 11/15/2022] Open
Affiliation(s)
- A MacKenna
- Unit of Reproductive Medicine, Clinica Las Condes, Lo Fontecilla 441, 7591046, Santiago, Chile
| | - J E Schwarze
- Unit of Reproductive Medicine, Clinica Las Condes, Lo Fontecilla 441, 7591046, Santiago, Chile
| | - J Crosby
- Unit of Reproductive Medicine, Clinica Las Condes, Lo Fontecilla 441, 7591046, Santiago, Chile
| | - F Zegers-Hochschild
- Unit of Reproductive Medicine, Clinica Las Condes, Lo Fontecilla 441, 7591046, Santiago, Chile.,Program of Ethics and Public Policies in Human Reproduction, Universidad Diego Portales, Ejercito 250, 8370056, Santiago, Chile
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4
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Walker PD, Williams C, Weir ANM, Wang L, Crosby J, Race PR, Simpson TJ, Willis CL, Crump MP. Control of β‐Branching in Kalimantacin Biosynthesis: Application of13C NMR to Polyketide Programming. Angew Chem Int Ed Engl 2019; 58:12446-12450. [DOI: 10.1002/anie.201905482] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/12/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Paul D. Walker
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | | | - Angus N. M. Weir
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Luoyi Wang
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - John Crosby
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Paul R. Race
- School of BiochemistryUniversity of Bristol University Walk Bristol BS8 1TD UK
| | - Thomas J. Simpson
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | | | - Matthew P. Crump
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
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5
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Walker PD, Williams C, Weir ANM, Wang L, Crosby J, Race PR, Simpson TJ, Willis CL, Crump MP. Control of β‐Branching in Kalimantacin Biosynthesis: Application of13C NMR to Polyketide Programming. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201905482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Paul D. Walker
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | | | - Angus N. M. Weir
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Luoyi Wang
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - John Crosby
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Paul R. Race
- School of BiochemistryUniversity of Bristol University Walk Bristol BS8 1TD UK
| | - Thomas J. Simpson
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
| | | | - Matthew P. Crump
- School of ChemistryUniversity of Bristol Cantock's Close Bristol BS8 1TS UK
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6
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Ellis BD, Milligan JC, White AR, Duong V, Altman PX, Mohammed LY, Crump MP, Crosby J, Luo R, Vanderwal CD, Tsai SC. An Oxetane-Based Polyketide Surrogate To Probe Substrate Binding in a Polyketide Synthase. J Am Chem Soc 2018; 140:4961-4964. [PMID: 29620883 DOI: 10.1021/jacs.7b11793] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polyketides are a large class of bioactive natural products with a wide range of structures and functions. Polyketides are biosynthesized by large, multidomain enzyme complexes termed polyketide synthases (PKSs). One of the primary challenges when studying PKSs is the high reactivity of their poly-β-ketone substrates. This has hampered structural and mechanistic characterization of PKS-polyketide complexes, and, as a result, little is known about how PKSs position the unstable substrates for proper catalysis while displaying high levels of regio- and stereospecificity. As a first step toward a general plan to use oxetanes as carbonyl isosteres to broadly interrogate PKS chemistry, we describe the development and application of an oxetane-based PKS substrate mimic. This enabled the first structural determination of the acyl-enzyme intermediate of a ketosynthase (KS) in complex with an inert extender unit mimic. The crystal structure, in combination with molecular dynamics simulations, led to a proposed mechanism for the unique activity of DpsC, the priming ketosynthase for daunorubicin biosynthesis. The successful application of an oxetane-based polyketide mimic suggests that this novel class of probes could have wide-ranging applications to the greater biosynthetic community interested in the mechanistic enzymology of iterative PKSs.
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Affiliation(s)
- Bryan D Ellis
- Department of Chemistry , University of California Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Jacob C Milligan
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences , University of California Irvine , 2218 Natural Sciences I , Irvine , California 92697 , United States
| | - Alexander R White
- Department of Chemistry , University of California Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Vy Duong
- Departments of Molecular Biology and Biochemistry, Biomedical Engineering, and Chemical Engineering & Materials Science , University of California Irvine , 2218 Natural Sciences I , Irvine , California 92697 , United States
| | - Pilar X Altman
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences , University of California Irvine , 2218 Natural Sciences I , Irvine , California 92697 , United States
| | - Lina Y Mohammed
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
| | - Matthew P Crump
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
| | - John Crosby
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
| | - Ray Luo
- Departments of Molecular Biology and Biochemistry, Biomedical Engineering, and Chemical Engineering & Materials Science , University of California Irvine , 2218 Natural Sciences I , Irvine , California 92697 , United States
| | - Christopher D Vanderwal
- Department of Chemistry , University of California Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Shiou-Chuan Tsai
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences , University of California Irvine , 2218 Natural Sciences I , Irvine , California 92697 , United States
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7
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Harper MJ, Arthur CJ, Crosby J, Emmett EJ, Falconer RL, Fensham-Smith AJ, Gates PJ, Leman T, McGrady JE, Bower JF, Russell CA. Oxidative Addition, Transmetalation, and Reductive Elimination at a 2,2'-Bipyridyl-Ligated Gold Center. J Am Chem Soc 2018; 140:4440-4445. [PMID: 29553258 DOI: 10.1021/jacs.8b01411] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Three-coordinate bipyridyl complexes of gold, [(κ2-bipy)Au(η2-C2H4)][NTf2], are readily accessed by direct reaction of 2,2'-bipyridine (bipy), or its derivatives, with the homoleptic gold ethylene complex [Au(C2H4)3][NTf2]. The cheap and readily available bipyridyl ligands facilitate oxidative addition of aryl iodides to the Au(I) center to give [(κ2-bipy)Au(Ar)I][NTf2], which undergo first aryl-zinc transmetalation and second C-C reductive elimination to produce biaryl products. The products of each distinct step have been characterized. Computational techniques are used to probe the mechanism of the oxidative addition step, offering insight into both the origin of the reversibility of this process and the observation that electron-rich aryl iodides add faster than electron-poor substrates. Thus, for the first time, all steps that are characteristic of a conventional intermolecular Pd(0)-catalyzed biaryl synthesis are demonstrated from a common monometallic Au complex and in the absence of directing groups.
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Affiliation(s)
- Matthew J Harper
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | - Christopher J Arthur
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | - John Crosby
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | - Edward J Emmett
- Syngenta, Jealott's Hill International Research Centre , Bracknell , Berkshire RG42 6EY , United Kingdom
| | - Rosalyn L Falconer
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | | | - Paul J Gates
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | - Thomas Leman
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
| | - John E McGrady
- Department of Chemistry , University of Oxford , South Parks Road , Oxford , OX1 3QZ , United Kingdom
| | - John F Bower
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , United Kingdom
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8
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Jackson DR, Shakya G, Patel AB, Mohammed LY, Vasilakis K, Wattana-Amorn P, Valentic TR, Milligan JC, Crump MP, Crosby J, Tsai SC. Structural and Functional Studies of the Daunorubicin Priming Ketosynthase DpsC. ACS Chem Biol 2018; 13:141-151. [PMID: 29161022 DOI: 10.1021/acschembio.7b00551] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Daunorubicin is a type II polyketide, one of a large class of polyaromatic natural products with anticancer, antibiotic, and antiviral activity. Type II polyketides are formed by the assembly of malonyl-CoA building blocks, though in rare cases, biosynthesis is initiated by the incorporation of a nonmalonyl derived starter unit, which adds molecular diversity to the poly-β-ketone backbone. Priming mechanisms for the transfer of novel starter units onto polyketide synthases (PKS) are still poorly understood. Daunorubicin biosynthesis incorporates a unique propionyl starter unit thought to be selected for by a subclass ("DpsC type") of priming ketosynthases (KS III). To date, however, no structural information exists for this subclass of KS III enzymes. Although selectivity for self-acylation with propionyl-CoA has previously been implied, we demonstrate that DpsC shows no discrimination for self-acylation or acyl-transfer to the cognate acyl carrier protein, DpsG with short acyl-CoAs. We present five crystal structures of DpsC, including apo-DpsC, acetyl-DpsC, propionyl-DpsC, butyryl-DpsC, and a cocrystal of DpsC with a nonhydrolyzable phosphopantetheine (PPant) analogue. The DpsC crystal structures reveal the architecture of the active site, the molecular determinants for catalytic activity and homology to O-malonyl transferases, but also indicate distinct differences. These results provide a structural basis for rational engineering of starter unit selection in type II polyketide synthases.
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Affiliation(s)
- David R. Jackson
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
| | - Gaurav Shakya
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
| | - Avinash B. Patel
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
| | - Lina Y. Mohammed
- School
of Chemistry, Cantock’s Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Kostas Vasilakis
- School
of Chemistry, Cantock’s Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Pakorn Wattana-Amorn
- School
of Chemistry, Cantock’s Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Timothy R. Valentic
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
| | - Jacob C. Milligan
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
| | - Matthew P. Crump
- School
of Chemistry, Cantock’s Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - John Crosby
- School
of Chemistry, Cantock’s Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Shiou-Chuan Tsai
- Department
of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, Irvine, California 92697, United States
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9
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Crosby J. [Recommandations de Choisir avec soin Canada]. Can Fam Physician 2016; 62:e373-e374. [PMID: 27412224 PMCID: PMC4955102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- John Crosby
- Médecin de famille et dirige 2 centres de soins de longue durée à Cambridge, en Ontario
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10
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Crosby J. Choosing Wisely Canada recommendations. Can Fam Physician 2016; 62:568. [PMID: 27412210 PMCID: PMC4955085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- John Crosby
- Family physician who runs 2 long-term care homes in Cambridge, Ont
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11
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Cohn C, Leung SL, Crosby J, Lafuente B, Zha Z, Teng W, Downs R, Wu X. Lipid-mediated protein functionalization of electrospun polycaprolactone fibers. EXPRESS POLYM LETT 2016; 10:430-437. [PMID: 32206095 DOI: 10.3144/expresspolymlett.2016.40] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In this study, electrospun polycaprolactone (PCL) fibers are plasma-treated and chemically conjugated with cholesteryl succinyl silane (CSS). In addition to Raman spectroscopy, an immobilization study of DiO as a fluorescent probe of lipid membranes provides evidence supporting the CSS coating of plasma-treated PCL fibers. Further, anti-CD20 antibodies are used as a model protein to evaluate the potential of lipid-mediated protein immobilization as a mechanism to functionalize the CSS-PCL fiber scaffolds. Upon anti-CD20 functionalization, the CSS-PCL fiber scaffolds capture Granta-22 cells 2.4 times more than the PCL control does, although the two fiber scaffolds immobilize a comparable amount of anti-CD20. Taken together, results from the present study demonstrate that the CSS coating and CSS-mediated antibody immobilization offers an appealing strategy to functionalize electrospun synthetic polymer fibers and confer cell-specific functions on the fiber scaffolds, which can be mechanically robust but often lack biological functions.
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Affiliation(s)
- C Cohn
- Biomedical Engineering Graduate IDP, University of Arizona, AZ 85721 Tucson, USA
| | - S L Leung
- Aerospace & Mechanical Engineering, University of Arizona, AZ 85721 Tucson, USA
| | - J Crosby
- Biomedical Engineering Graduate IDP, University of Arizona, AZ 85721 Tucson, USA
| | - B Lafuente
- Department of Geosciences, University of Arizona, AZ 85721 Tucson, USA
| | - Z Zha
- Aerospace & Mechanical Engineering, University of Arizona, AZ 85721 Tucson, USA
| | - W Teng
- Aerospace & Mechanical Engineering, University of Arizona, AZ 85721 Tucson, USA
| | - R Downs
- Department of Geosciences, University of Arizona, AZ 85721 Tucson, USA
| | - X Wu
- Biomedical Engineering Graduate IDP, University of Arizona, AZ 85721 Tucson, USA.,Aerospace & Mechanical Engineering, University of Arizona, AZ 85721 Tucson, USA
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12
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Dong X, Bailey CD, Williams C, Crosby J, Simpson TJ, Willis CL, Crump MP. Recognition of extended linear and cyclised polyketide mimics by a type II acyl carrier protein. Chem Sci 2016; 7:1779-1785. [PMID: 28936328 PMCID: PMC5595124 DOI: 10.1039/c5sc03864b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/08/2015] [Indexed: 12/02/2022] Open
Abstract
Polyketides are secondary metabolites which display both valuable pharmaceutical and agrochemical properties. Biosynthesis is performed by polyketide synthases (PKSs), and the acyl carrier protein (ACP), a small acidic protein, that transports the growing polyketide chain and is essential for activity. Here we report the synthesis of two aromatic probes and a linear octaketide mimic that have been tethered to actinorhodin ACP. These experiments were aimed at probing the ACP's capacity to sequester a non-polar versus a phenolic aromatic ring (that more closely mimics a polyketide intermediate) as well as investigations with extended polyketide chain surrogates. The binding of these mimics has been assessed using high-resolution solution NMR studies and high-resolution structure determination. These results reveal that surprisingly a PKS ACP is able to bind and sequester a bulky non-polar substrate containing an aromatic ring in a fatty acid type binding mode, but the introduction of even a small degree of polarity favours a markedly different association at a surface site that is distinct from that employed by fatty acid ACPs.
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Affiliation(s)
- Xu Dong
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - Christopher D Bailey
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - Christopher Williams
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - John Crosby
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - Thomas J Simpson
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - Christine L Willis
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
| | - Matthew P Crump
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , UK . ;
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13
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Buckenmeyer PJ, Hokanson JF, Yang SP, Bauer JA, Hendrick JL, Wilber A, Haupage S, Manico K, Crosby J. Effect Of 5-hour Energy Shot® On Simulated Car Racing Ability Of College-aged Individuals. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000495714.93665.88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Murphy AC, Gao SS, Han LC, Carobene S, Fukuda D, Song Z, Hothersall J, Cox RJ, Crosby J, Crump MP, Thomas CM, Willis CL, Simpson TJ. Biosynthesis of thiomarinol A and related metabolites of Pseudoalteromonas sp. SANK 73390. Chem Sci 2014. [DOI: 10.1039/c3sc52281d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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15
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Haines AS, Dong X, Song Z, Farmer R, Williams C, Hothersall J, Płoskoń E, Wattana-Amorn P, Stephens ER, Yamada E, Gurney R, Takebayashi Y, Masschelein J, Cox RJ, Lavigne R, Willis CL, Simpson TJ, Crosby J, Winn PJ, Thomas CM, Crump MP. A conserved motif flags acyl carrier proteins for β-branching in polyketide synthesis. Nat Chem Biol 2013; 9:685-692. [PMID: 24056399 PMCID: PMC4658705 DOI: 10.1038/nchembio.1342] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/22/2013] [Indexed: 11/14/2022]
Abstract
Type I PKSs often utilise programmed β-branching, via enzymes of an “HMG-CoA synthase (HCS) cassette”, to incorporate various side chains at the second carbon from the terminal carboxylic acid of growing polyketide backbones. We identified a strong sequence motif in Acyl Carrier Proteins (ACPs) where β-branching is known. Substituting ACPs confirmed a correlation of ACP type with β-branching specificity. While these ACPs often occur in tandem, NMR analysis of tandem β-branching ACPs indicated no ACP-ACP synergistic effects and revealed that the conserved sequence motif forms an internal core rather than an exposed patch. Modelling and mutagenesis identified ACP Helix III as a probable anchor point of the ACP-HCS complex whose position is determined by the core. Mutating the core affects ACP functionality while ACP-HCS interface substitutions modulate system specificity. Our method for predicting β-carbon branching expands the potential for engineering novel polyketides and lays a basis for determining specificity rules.
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Affiliation(s)
- Anthony S Haines
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Xu Dong
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Zhongshu Song
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Rohit Farmer
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | | | - Joanne Hothersall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Eliza Płoskoń
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | | | - Elton R Stephens
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Erika Yamada
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Rachel Gurney
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Yuiko Takebayashi
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Joleen Masschelein
- Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21 - box 2462, 3001 Heverlee, Belgium
| | - Russell J Cox
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Rob Lavigne
- Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21 - box 2462, 3001 Heverlee, Belgium
| | | | - Thomas J Simpson
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - John Crosby
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Peter J Winn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Christopher M Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Matthew P Crump
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
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16
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Javidpour P, Bruegger J, Srithahan S, Korman TP, Crump MP, Crosby J, Burkart MD, Tsai SC. The determinants of activity and specificity in actinorhodin type II polyketide ketoreductase. ACTA ACUST UNITED AC 2013; 20:1225-34. [PMID: 24035284 DOI: 10.1016/j.chembiol.2013.07.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 06/28/2013] [Accepted: 07/07/2013] [Indexed: 11/17/2022]
Abstract
In the actinorhodin type II polyketide synthase, the first polyketide modification is a regiospecific C9-carbonyl reduction, catalyzed by the ketoreductase (actKR). Our previous studies identified the actKR 94-PGG-96 motif as a determinant of stereospecificity. The molecular basis for reduction regiospecificity is, however, not well understood. In this study, we examined the activities of 20 actKR mutants through a combination of kinetic studies, PKS reconstitution, and structural analyses. Residues have been identified that are necessary for substrate interaction, and these observations have suggested a structural model for this reaction. Polyketides dock at the KR surface and are steered into the enzyme pocket where C7-C12 cyclization is mediated by the KR before C9-ketoreduction can occur. These molecular features can potentially serve as engineering targets for the biosynthesis of novel, reduced polyketides.
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Affiliation(s)
- Pouya Javidpour
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, USA
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17
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Ross JF, Delipala C, Watson MC, Crosby J, Paton RM. Nitrile sulfides Part 16. Synthesis of 1,2-benzisothiazoles via nitrile sulfide cycloaddition reactions. ARKIVOC 2013. [DOI: 10.3998/ark.5550190.p008.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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18
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Maple HJ, Garlish RA, Whitcombe I, Hold A, Prosser CE, Ford D, Mackenzie H, Crosby J, Porter J, Taylor RJ, Crump MP. Identification of Differential Protein Binding Affinities in an Atropisomeric Pharmaceutical Compound by Noncovalent Mass Spectrometry, Equilibrium Dialysis, and Nuclear Magnetic Resonance. Anal Chem 2013; 85:5958-64. [DOI: 10.1021/ac400760p] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hannah J. Maple
- School of
Chemistry, University of Bristol, Cantock’s
Close, Clifton,
Bristol BS8 1TS, United Kingdom
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Rachel A. Garlish
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Ian Whitcombe
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Adam Hold
- LC/MS Consulting Limited, St. Albans, Hertfordshire AL1 3BZ, United Kingdom
| | | | - Daniel Ford
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Harry Mackenzie
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - John Crosby
- School of
Chemistry, University of Bristol, Cantock’s
Close, Clifton,
Bristol BS8 1TS, United Kingdom
| | - John Porter
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Richard J. Taylor
- UCB Pharma, 216 Bath Road, Slough, Berkshire
SL1 4EN, United Kingdom
| | - Matthew P. Crump
- School of
Chemistry, University of Bristol, Cantock’s
Close, Clifton,
Bristol BS8 1TS, United Kingdom
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19
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Crosby J, Treadwell T, Hammerton M, Vasilakis K, Crump MP, Williams DS, Mann S. Stabilization and enhanced reactivity of actinorhodin polyketide synthase minimal complex in polymer-nucleotide coacervate droplets. Chem Commun (Camb) 2013; 48:11832-4. [PMID: 23099989 DOI: 10.1039/c2cc36533b] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Compartmentalization of the minimal complex of actinorhodin polyketide synthase in coacervate liquid droplets produces enhanced yields of shunt polyketides under conditions of low and high ionic strength.
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Affiliation(s)
- John Crosby
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
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20
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Abstract
Common to all FASs, PKSs and NRPSs is a remarkable component, the acyl or peptidyl carrier protein (A/PCP). These take the form of small individual proteins in type II systems or discrete folded domains in the multi-domain type I systems and are characterized by a fold consisting of three major α-helices and between 60-100 amino acids. This protein is central to these biosynthetic systems and it must bind and transport a wide variety of functionalized ligands as well as mediate numerous protein-protein interactions, all of which contribute to efficient enzyme turnover. This review covers the structural and biochemical characterization of carrier proteins, as well as assessing their interactions with different ligands, and other synthase components. Finally, their role as an emerging tool in biotechnology is discussed.
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Affiliation(s)
- John Crosby
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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21
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Zaninovic N, Rosenwaks Z, Iager AE, Kocabas AM, Otu HH, Ruppel P, Langerveld A, Schnarr P, Suarez M, Jarrett JC, Conaghan J, Rosa GJM, Fernandez E, Rawlins RG, Cibelli JB, Crosby J, Kirkegaard K, Hindkjaer J, Ingerslev HJ, Lykke-Hartmann K, Himaya E, Jamal W, Phillips S, Delrieu D, Hamamah S, Kadoch IJ, Cortezzi SS, Cabral EC, Ferreira CR, Trevisan MG, Figueira RCS, Eberlin MN, Iaconelli A, Borges E, Chimote NM, Chimote NN, Nath NM, Chimote MN, Mehta BN. SESSION 02: EMBRYOLOGY - BIOMARKERS. Hum Reprod 2012. [DOI: 10.1093/humrep/27.s2.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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22
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Khan AZ, Shafafy M, Latimer MD, Crosby J. A lipoma within the Achilles tendon sheath. Foot Ankle Surg 2012; 18:e16-7. [PMID: 22326013 DOI: 10.1016/j.fas.2011.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 09/17/2011] [Accepted: 10/06/2011] [Indexed: 02/04/2023]
Abstract
We report a case demonstrating a rare finding associated with a relatively common injury. Lipomata are rarely found within tendon sheaths; but in the case of our patient, at the time of operative repair for a ruptured Achilles tendon, we found a fatty growth within the tendon sheath. The diagnosis of a lipoma was confirmed by histology. Although uncommon, it remains important to be aware of the existence of neoplastic growths within tendon sheaths and to establish the exact nature of these growths by histological analysis.
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Affiliation(s)
- Asif Z Khan
- Peterborough and Stamford Hospitals NHS Foundation Trust, Department of Trauma & Orthopaedics, Peterborough City Hospital, Edith Cavell Campus, Bretton Gate, Bretton, Peterborough PE3 9GZ, United Kingdom.
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23
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Maple HJ, Garlish RA, Rigau-Roca L, Porter J, Whitcombe I, Prosser CE, Kennedy J, Henry AJ, Taylor RJ, Crump MP, Crosby J. Automated Protein–Ligand Interaction Screening by Mass Spectrometry. J Med Chem 2012; 55:837-51. [DOI: 10.1021/jm201347k] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hannah J. Maple
- School of Chemistry, University of Bristol, Cantock’s
Close, Clifton, Bristol BS8 1TS, United Kingdom
| | - Rachel A. Garlish
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | - Laura Rigau-Roca
- School of Chemistry, University of Bristol, Cantock’s
Close, Clifton, Bristol BS8 1TS, United Kingdom
| | - John Porter
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | - Ian Whitcombe
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | | | - Jeff Kennedy
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | - Alistair J. Henry
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | - Richard J. Taylor
- UCB Pharma, 216 Bath Road, Slough, Berkshire SL1 4EN, United Kingdom
| | - Matthew P. Crump
- School of Chemistry, University of Bristol, Cantock’s
Close, Clifton, Bristol BS8 1TS, United Kingdom
| | - John Crosby
- School of Chemistry, University of Bristol, Cantock’s
Close, Clifton, Bristol BS8 1TS, United Kingdom
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24
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Dall’Aglio P, Arthur CJ, Williams C, Vasilakis K, Maple HJ, Crosby J, Crump MP, Hadfield AT. Analysis of Streptomyces coelicolor Phosphopantetheinyl Transferase, AcpS, Reveals the Basis for Relaxed Substrate Specificity. Biochemistry 2011; 50:5704-17. [DOI: 10.1021/bi2003668] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Patrick Dall’Aglio
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Clifton, Bristol BS8 1TD, U.K
| | - Christopher J. Arthur
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - Christopher Williams
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - Konstantinos Vasilakis
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - Hannah J. Maple
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - John Crosby
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - Matthew P. Crump
- School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol BS8 1TS, U.K
| | - Andrea T. Hadfield
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Clifton, Bristol BS8 1TD, U.K
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25
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Hothersall J, Murphy AC, Iqbal Z, Campbell G, Stephens ER, Wu J, Cooper H, Atkinson S, Williams P, Crosby J, Willis CL, Cox RJ, Simpson TJ, Thomas CM. Manipulation of quorum sensing regulation in Pseudomonas fluorescens NCIMB 10586 to increase mupirocin production. Appl Microbiol Biotechnol 2011; 90:1017-26. [PMID: 21318358 DOI: 10.1007/s00253-011-3145-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 01/18/2011] [Accepted: 01/21/2011] [Indexed: 11/28/2022]
Abstract
Transcription of the 74 kb Pseudomonas fluorescens mupirocin [pseudomonic acid (PA)] biosynthesis cluster depends on quorum sensing-dependent regulation via the LuxI/LuxR homologues MupI/MupR. To facilitate analysis of novel PAs from pathway mutants, we investigated factors that affect mup gene expression. First, the signal produced by MupI was identified as N-(3-oxodecanoyl)homoserine lactone, but exogenous addition of this molecule did not activate mupirocin production prematurely nor did expression of mupI in trans increase metabolite production. Second, we confirmed that mupX, encoding an amidase/hydrolase that can degrade N-acylhomoserine lactones, is also required for efficient expression, consistent with its occurrence in a regulatory module linked to unrelated genes in P. fluorescens. Third, and most significantly, mupR expression in trans to wild type and mutants can increase production of antibiotic and novel intermediates up to 17-fold.
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Affiliation(s)
- Joanne Hothersall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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26
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Reid-Nicholson M, Kulkarni R, Adeagbo B, Looney S, Crosby J. Interobserver and intraobserver variability in the calculation of the lipid-laden macrophage index: Implications for its use in the evaluation of aspiration in children. Diagn Cytopathol 2010; 38:861-5. [DOI: 10.1002/dc.21298] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Płoskoń E, Arthur CJ, Kanari AL, Wattana-amorn P, Williams C, Crosby J, Simpson TJ, Willis CL, Crump MP. Recognition of Intermediate Functionality by Acyl Carrier Protein over a Complete Cycle of Fatty Acid Biosynthesis. ACTA ACUST UNITED AC 2010; 17:776-85. [DOI: 10.1016/j.chembiol.2010.05.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 04/28/2010] [Accepted: 05/14/2010] [Indexed: 10/19/2022]
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28
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Wattana-amorn P, Williams C, Płoskoń E, Cox RJ, Simpson TJ, Crosby J, Crump MP. Solution Structure of an Acyl Carrier Protein Domain from a Fungal Type I Polyketide Synthase,. Biochemistry 2010; 49:2186-93. [DOI: 10.1021/bi902176v] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pakorn Wattana-amorn
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Christopher Williams
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Eliza Płoskoń
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Russell J. Cox
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Thomas J. Simpson
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - John Crosby
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Matthew P. Crump
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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29
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Shields JA, Rahman AS, Arthur CJ, Crosby J, Hothersall J, Simpson TJ, Thomas CM. Phosphopantetheinylation and Specificity of Acyl Carrier Proteins in the Mupirocin Biosynthetic Cluster. Chembiochem 2009; 11:248-55. [DOI: 10.1002/cbic.200900565] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Arthur CJ, Williams C, Pottage K, Płoskoń E, Findlow SC, Burston SG, Simpson TJ, Crump MP, Crosby J. Structure and malonyl CoA-ACP transacylase binding of streptomyces coelicolor fatty acid synthase acyl carrier protein. ACS Chem Biol 2009; 4:625-36. [PMID: 19555075 DOI: 10.1021/cb900099e] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Malonylation of an acyl carrier protein (ACP) by malonyl Coenzyme A-ACP transacylase (MCAT) is fundamental to bacterial fatty acid biosynthesis. Here, we report the structure of the Steptomyces coelicolor (Sc) fatty acid synthase (FAS) ACP and studies of its binding to MCAT. The carrier protein adopts an alpha-helical bundle structure common to other known carrier proteins. The Sc FAS ACP shows close structural homology with other fatty acid ACPs and less similarity with Sc actinorhodin (act) polyketide synthase (PKS) ACP where the orientation of helix I differs. NMR experiments were used to map the binding of ACP to MCAT. This data suggests that Sc FAS ACP interacts with MCAT through the negatively charged helix II of ACP, consistent with proposed models for ACP recognition by other FAS enzymes. Differential roles for residues at the interface are demonstrated using site-directed mutagenesis and in vitro assays. MCAT has been suggested, moreover, to participate in bacterial polyketide synthesis in vivo. We demonstrate that the affinity of the polyketide synthase ACP for MCAT is lower than that of the FAS ACP. Mutagenesis of homologous helix II residues on the polyketide synthase ACP suggests that the PKS ACP may bind to MCAT in a different manner than the FAS counterpart.
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Affiliation(s)
| | - Christopher Williams
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Katherine Pottage
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, U.K
| | - Eliza Płoskoń
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Stuart C. Findlow
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, U.K
| | - Steven G. Burston
- Department of Biochemistry, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, U.K
| | - Thomas J. Simpson
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Matthew P. Crump
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - John Crosby
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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31
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Hunt JR, Carter AS, Murrell JC, Dalton H, Hallinan KO, Crout DHG, Holt RA, Crosby J. Yeast Catalysed Reduction of β-Keto Esters (1): Factors Affecting Whole-Cell Catalytic Activity and Stereoselectivity. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242429508998160] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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32
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Hallinan KO, Crout DHG, Hunt JR, Carter AS, Dalton H, Murrell JC, Holt RA, Crosby J. Yeast Catalysed Reduction of β-Keto Esters (2): Optimisation of the Stereospecific Reduction by Zygosaccharomyces Rouxii. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.3109/10242429508998161] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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33
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Evans SE, Williams C, Arthur CJ, Płoskoń E, Wattana-amorn P, Cox RJ, Crosby J, Willis CL, Simpson TJ, Crump MP. Probing the Interactions of Early Polyketide Intermediates with the Actinorhodin ACP from S. coelicolor A3(2). J Mol Biol 2009; 389:511-28. [DOI: 10.1016/j.jmb.2009.03.072] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 03/25/2009] [Accepted: 03/25/2009] [Indexed: 10/20/2022]
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34
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Beltran-Alvarez P, Arthur CJ, Cox RJ, Crosby J, Crump MP, Simpson TJ. Preliminary kinetic analysis of acyl carrier protein–ketoacylsynthase interactions in the actinorhodin minimal polyketide synthase. Mol BioSyst 2009; 5:511-8. [DOI: 10.1039/b821844g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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35
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Castaldo G, Zucko J, Heidelberger S, Vujaklija D, Hranueli D, Cullum J, Wattana-Amorn P, Crump MP, Crosby J, Long PF. Proposed Arrangement of Proteins Forming a Bacterial Type II Polyketide Synthase. ACTA ACUST UNITED AC 2008; 15:1156-65. [DOI: 10.1016/j.chembiol.2008.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 08/09/2008] [Accepted: 09/04/2008] [Indexed: 11/16/2022]
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36
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Evans SE, Williams C, Arthur CJ, Burston SG, Simpson TJ, Crosby J, Crump MP. An ACP Structural Switch: Conformational Differences between the Apo and Holo Forms of the Actinorhodin Polyketide Synthase Acyl Carrier Protein. Chembiochem 2008; 9:2424-32. [DOI: 10.1002/cbic.200800180] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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37
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Wu J, Hothersall J, Mazzetti C, O'Connell Y, Shields JA, Rahman AS, Cox RJ, Crosby J, Simpson TJ, Thomas CM, Willis CL. In vivo mutational analysis of the mupirocin gene cluster reveals labile points in the biosynthetic pathway: the "leaky hosepipe" mechanism. Chembiochem 2008; 9:1500-8. [PMID: 18465759 DOI: 10.1002/cbic.200800085] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A common feature of the mupirocin and other gene clusters of the AT-less polyketide synthase (PKS) family of metabolites is the introduction of carbon branches by a gene cassette that contains a beta-hydroxy-beta-methylglutaryl CoA synthase (HMC) homologue and acyl carrier protein (ACP), ketosynthase (KS) and two crotonase superfamily homologues. In vivo studies of Pseudomonas fluorescens strains in which any of these components have been mutated reveal a common phenotype in which the two major isolable metabolites are the truncated hexaketide mupirocin H and the tetraketide mupiric acid. The structure of the latter has been confirmed by stereoselective synthesis. Mupiric acid is also the major metabolite arising from inactivation of the ketoreductase (KR) domain of module 4 of the modular PKS. A number of other mutations in the tailoring region of the mupirocin gene cluster also result in production of both mupirocin H and mupiric acid. To explain this common phenotype we propose a mechanistic rationale in which both mupirocin H and mupiric acid represent the products of selective and spontaneous release from labile points in the pathway that occur at significant levels when mutations block the pathway either close to or distant from the labile points.
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Affiliation(s)
- Ji'en Wu
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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38
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Ploskoń E, Arthur CJ, Evans SE, Williams C, Crosby J, Simpson TJ, Crump MP. A Mammalian Type I Fatty Acid Synthase Acyl Carrier Protein Domain Does Not Sequester Acyl Chains. J Biol Chem 2008; 283:518-528. [DOI: 10.1074/jbc.m703454200] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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39
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Beltran-Alvarez P, Cox RJ, Crosby J, Simpson TJ. Dissecting the component reactions catalyzed by the actinorhodin minimal polyketide synthase. Biochemistry 2007; 46:14672-81. [PMID: 18034463 DOI: 10.1021/bi701784c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The actinorhodin (act) minimal polyketide synthase (PKS) from Streptomyces coelicolor consists of three proteins: an acyl carrier protein (ACP) and two beta-ketoacyl ACP synthase components known as KSalpha and KSbeta. The act minimal PKS catalyzes at least 18 separate reactions which can be divided into loading, initiation, extension, and cyclization and release phases. Two quantitative kinetic assays were developed and used to measure individual rate and Michaelis constants for loading, initiation and extension steps. In the minimal PKS, the reaction between malonyl CoA and ACP to form malonyl ACP (loading) is the rate-limiting step (kcat = 0.49 min-1, KM = 207 microM). This reaction increases 5-fold in rate in the presence of KSalphaKSbeta (kcat = 2.3 min-1, KM = 215 microM). In the presence of S. coelicolor malonyl CoA:ACP transacylase (MCAT), the rate of loading increases and the kinetic parameters of malonyl-ACP as a substrate of KSalphaKSbeta can be measured (kcat = 20.6 min-1, KM = 2.4 microM). Under these conditions, it appears that decarboxylation of malonyl-ACP to form acetyl-ACP (initiation) is the rate-limiting step. When an excess of acetyl ACP is supplied, either chain extension, cyclization, or release steps become rate limiting (k approximately 60 min-1). No ACP-bound intermediates could be observed, suggesting that partially or fully extended chains do not accumulate because chain extension is rate limiting under these conditions and that cyclization and release are fast. apo-ACP acts as a mixed inhibitor of malonyl ACP binding to KSalpha/KSbeta (Kic = 50 microM, Kiu = 137 microM), but apo-ACP does not appear to inhibit MCAT.
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40
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Williams C, Rezgui D, Prince SN, Zaccheo OJ, Foulstone EJ, Forbes BE, Norton RS, Crosby J, Hassan AB, Crump MP. Structural insights into the interaction of insulin-like growth factor 2 with IGF2R domain 11. Structure 2007; 15:1065-78. [PMID: 17850746 DOI: 10.1016/j.str.2007.07.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 06/18/2007] [Accepted: 07/06/2007] [Indexed: 11/25/2022]
Abstract
The insulin-like growth factor II/mannose-6-phosphate receptor (IGF2R) mediates trafficking of mannose-6-phosphate (M6P)-containing proteins and the mitogenic hormone IGF2. IGF2R also plays an important role as a tumor suppressor, as mutation is frequently associated with human carcinogenesis. IGF2 binds to domain 11, one of 15 extracellular domains on IGF2R. The crystal structure of domain 11 and the solution structure of IGF2 have been reported, but, to date, there has been limited success when using crystallography to study the interaction of IGFs with their binding partners. As an approach to investigate the interaction between IGF2 and IGF2R, we have used heteronuclear NMR in combination with existing mutagenesis data to derive models of the domain 11-IGF2 complex by using the program HADDOCK. The models reveal that the molecular interaction is driven by critical hydrophobic residues on IGF2 and IGF2R, while a ring of flexible, charged residues on IGF2R may modulate binding.
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Affiliation(s)
- Christopher Williams
- Department of Organic and Biological Chemistry, School of Chemistry, Cantock's Close, University of Bristol, Bristol, United Kingdom
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41
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Hothersall J, Wu J, Rahman AS, Shields JA, Haddock J, Johnson N, Cooper SM, Stephens ER, Cox RJ, Crosby J, Willis CL, Simpson TJ, Thomas CM. Mutational Analysis Reveals That All Tailoring Region Genes Are Required for Production of Polyketide Antibiotic Mupirocin by Pseudomonas fluorescens. J Biol Chem 2007; 282:15451-61. [PMID: 17383964 DOI: 10.1074/jbc.m701490200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Pseudomonas fluorescens mupirocin biosynthetic cluster encodes six proteins involved in polyketide biosynthesis and 26 single polypeptides proposed to perform largely tailoring functions. In-frame deletions in the tailoring open reading frames demonstrated that all are required for mupirocin production. A bidirectional promoter region was identified between mupF, which runs counter to other open reading frames and its immediate neighbor macpC, implying the 74-kb cluster consists of two transcriptional units. mupD/E and mupJ/K must be cotranscribed as pairs for normal function implying co-assembly during translation. MupJ and K belong to a widely distributed enzyme pair implicated, with MupH, in methyl addition. Deletion of mupF, a putative ketoreductase, produced a mupirocin analogue with a C-7 ketone. Deletion of mupC, a putative dienoyl CoA reductase, generated an analogue whose structure indicated that MupC is also implicated in control of the oxidation state around the tetrahydropyran ring of monic acid. Double mutants with DeltamupC and DeltamupO, DeltamupU, DeltamupV, or DeltamacpE produced pseudomonic acid B but not pseudomonic acid A, as do the mupO, U, V, and macpE mutants, indicating that MupC must work after MupO, U, and V.
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Affiliation(s)
- Joanne Hothersall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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42
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Wu J, Cooper SM, Cox RJ, Crosby J, Crump MP, Hothersall J, Simpson TJ, Thomas CM, Willis CL. Mupirocin H, a novel metabolite resulting from mutation of the HMG-CoA synthase analogue, mupH in Pseudomonas fluorescens. Chem Commun (Camb) 2007:2040-2. [PMID: 17713071 DOI: 10.1039/b700613f] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mutation of the HMG-CoA synthase encoding mupH gene in Pseudomonas fluorescens gives rise to a new metabolite formed from a truncated polyketide intermediate, providing in vivo evidence for the roles of mupH and cognate genes found in several "AT-less" and other bacterial PKS gene clusters responsible for the biosynthesis of diverse metabolites containing acetate/propionate derived side chains.
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Affiliation(s)
- Ji'en Wu
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK
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43
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Arthur CJ, Szafranska AE, Long J, Mills J, Cox RJ, Findlow SC, Simpson TJ, Crump MP, Crosby J. The malonyl transferase activity of type II polyketide synthase acyl carrier proteins. ACTA ACUST UNITED AC 2006; 13:587-96. [PMID: 16793516 DOI: 10.1016/j.chembiol.2006.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/13/2006] [Accepted: 03/24/2006] [Indexed: 11/21/2022]
Abstract
Acyl carrier proteins (ACPs) play a fundamental role in directing intermediates among the enzyme active sites of fatty acid and polyketide synthases (PKSs). In this paper, we demonstrate that the Streptomyces coelicolor (S. coelicolor) actinorhodin (act) PKS ACP can catalyze transfer of malonate to type II S. coelicolor fatty acid synthase (FAS) and other PKS ACPs in vitro. The reciprocal transfer from S. coelicolor FAS ACP to a PKS ACP was not observed. Several mutations in both act ACP and S. coelicolor FAS ACP could be classified by their participation in either donation or acceptance of this malonyl group. These mutations indicated that self-malonylation and malonyl transfer could be completely decoupled, implying that they were separate processes and that a FAS ACP could be converted from a non-malonyl-transferring protein to one with malonyl transferase activity.
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Affiliation(s)
- Christopher J Arthur
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
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44
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Abstract
Bulgecin A, a sulphonated N-acetyl-D-glucosamine unit linked to a 4-hydroxy-5-hydroxymethylproline ring by a beta-glycosidic linkage, is a novel type of inhibitor for binuclear metallo-beta-lactamases. Using steady-state kinetic analysis with nitrocefin as the beta-lactam substrate, bulgecin A competitively inhibited the metallo-beta-lactamase BceII from Bacillus cereus in its two-zinc form, but failed to inhibit when the enzyme was in the single-zinc form. The competitive inhibition was restored by restoring the second zinc ion. The single-zinc metallo-beta-lactamase from Aeromonas veronii bv. sobria, ImiS, was not inhibited by bulgecin A. The tetrameric L1 metallo-beta-lactamase from Stenotrophomonas maltophilia was subject to partial non-competitive inhibition, which is consistent with a kinetic model in which the enzyme bound to inhibitor retains catalytic activity. Docking experiments support the conclusion that bulgecin A co-ordinates to the zinc II site in metallo-beta-lactamases via the terminal sulphonate group on the sugar moiety.
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Affiliation(s)
- Alan M Simm
- Department of Pathology and Microbiology, University of Bristol, University Walk, Bristol BS8 1TD, UK.
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45
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Arthur CJ, Szafranska A, Evans SE, Findlow SC, Burston SG, Owen P, Clark-Lewis I, Simpson TJ, Crosby J, Crump MP. Self-malonylation is an intrinsic property of a chemically synthesized type II polyketide synthase acyl carrier protein. Biochemistry 2006; 44:15414-21. [PMID: 16285746 DOI: 10.1021/bi051499i] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
During polyketide biosynthesis, malonyl groups are transferred to the acyl carrier protein (ACP) component of the polyketide synthase (PKS), and it has been shown that a number of type II polyketide ACPs undergo rapid self-acylation from malonyl-CoA in the absence of a malonyl-CoA:holo-acyl carrier protein transacylase (MCAT). More recently, however, the observation of self-malonylation has been ascribed to contamination with Escherichia coli MCAT (FabD) rather than an intrinsic property of the ACP. The wild-type apo-ACP from the actinorhodin (act) PKS of Streptomyces coelicolor (synthetic apo-ACP) has therefore been synthesized using solid-state peptide methods and refolded using the GroEL/ES chaperone system from E. coli. Correct folding of the act ACP has been confirmed by circular dichroism (CD) and 1H NMR. Synthetic apo-ACP was phosphopantetheinylated to 100% by S. coelicolor holo-acyl carrier protein synthase (ACPS), and the resultant holo-ACP underwent self-malonylation in the presence of malonyl-CoA. No malonylation of negative controls was observed, confirming that the use of ACPS and GroEL/ES did not introduce contamination with E. coli MCAT. This result proves unequivocally that self-malonylation is an inherent activity of this PKS ACP in vitro.
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Affiliation(s)
- Christopher J Arthur
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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46
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Marsh M, Limpkin C, Teartasin W, Simpson TJ, Crosby J, Crump MP, Hadfield AT. Active site structure of actinorhodin polyketide ( actIII) reductase. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305092305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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47
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Cooper SM, Laosripaiboon W, Rahman AS, Hothersall J, El-Sayed AK, Winfield C, Crosby J, Cox RJ, Simpson TJ, Thomas CM. Shift to Pseudomonic Acid B Production in P. fluorescens NCIMB10586 by Mutation of Mupirocin Tailoring Genes mupO, mupU, mupV, and macpE. ACTA ACUST UNITED AC 2005; 12:825-33. [PMID: 16039529 DOI: 10.1016/j.chembiol.2005.05.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 04/11/2005] [Accepted: 05/16/2005] [Indexed: 10/25/2022]
Abstract
Mupirocin, a polyketide-derived antibiotic from Pseudomonas fluorescens NCIMB10586, is a mixture of pseudomonic acids (PA) that target isoleucyl-tRNA synthase. The mup gene cluster encodes both type I polyketide synthases and monofunctional enzymes that should play a role during the conversion of the product of the polyketide synthase into the active antibiotic (tailoring). By in-frame deletion analysis of selected tailoring open-reading frames we show that mupQ, mupS, mupT, and mupW are essential for mupirocin production, whereas mupO, mupU, mupV, and macpE are essential for production of PA-A but not PA-B. Therefore, PA-B is not simply produced by hydroxylation of PA-A but is either a precursor of PA-A or a shunt product. In the mupW mutant, a new metabolite lacking the tetrahydropyran ring is produced, implicating mupW in oxidation of the 16-methyl group.
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Affiliation(s)
- Sian M Cooper
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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48
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Parker CA, Anderson NJ, Robinson ESJ, Price R, Tyacke RJ, Husbands SM, Dillon MP, Eglen RM, Hudson AL, Nutt DJ, Crump MP, Crosby J. Harmane and harmalan are bioactive components of classical clonidine-displacing substance. Biochemistry 2005; 43:16385-92. [PMID: 15610033 DOI: 10.1021/bi048584v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elucidation of the structure of the endogenous ligand(s) for imidazoline binding sites, clonidine-displacing substance (CDS), has been a major goal for many years. Crude CDS from bovine lung was purified by reverse-phase high-pressure liquid chromatography. Electrospray mass spectrometry (ESMS) and nuclear magnetic resonance ((1)H NMR) analysis revealed the presence of L-tryptophan and 1-carboxy-1-methyltetrahydro-beta-carboline in the active CDS extract. Competition radioligand binding studies, however, failed to show displacement of specific [(3)H]clonidine binding to rat brain membranes for either compound. Further purification of the bovine lung extract allowed the isolation of the beta-carbolines harmane and harmalan as confirmed by ESMS, (1)H NMR, and comparison with synthetic standards. Both compounds exhibited a high (nanomolar) affinity for both type 1 and type 2 imidazoline binding sites, and the synthetic standards were shown to coelute with the active classical CDS extracts. We therefore propose that the beta-carbolines harmane and harmalan represent active components of classical CDS. The identification of these compounds will allow us to establish clear physiological roles for CDS.
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49
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Rahman AS, Hothersall J, Crosby J, Simpson TJ, Thomas CM. Tandemly Duplicated Acyl Carrier Proteins, Which Increase Polyketide Antibiotic Production, Can Apparently Function Either in Parallel or in Series. J Biol Chem 2005; 280:6399-408. [PMID: 15583005 DOI: 10.1074/jbc.m409814200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polyketide biosynthesis involves the addition of subunits commonly derived from malonate or methylmalonate to a starter unit such as acetate. Type I polyketide synthases are multifunctional polypeptides that contain one or more modules, each of which normally contains all the enzymatic domains for a single round of extension and modification of the polyketide backbone. Acyl carrier proteins (ACP(s)) hold the extender unit to which the starter or growing chain is added. Normally there is one ACP for each ketosynthase module. However, there are an increasing number of known examples of tandemly repeated ACP domains, whose function is as yet unknown. For the doublet and triplet ACP domains in the biosynthetic pathway for the antibiotic mupirocin from Pseudomonas fluorescens NCIMB10586 we have inactivated ACP domains by inframe deletion and amino acid substitution of the active site serine. By deletion analysis each individual ACP from a cluster can provide a basic but reduced activity for the pathway. In the doublet cluster, substitution analysis indicates that the pathway may follow two parallel routes, one via each of the ACPs, thus increasing overall pathway flow. In the triplet cluster, substitution in ACP5 blocked the pathway. Thus ACP5 appears to be arranged "in series" to ACP6 and ACP7. Thus although both the doublet and triplet clusters increase antibiotic production, the mechanisms by which they do this appear to be different and depend specifically on the biosynthetic stage involved. The function of some ACPs may be determined by their location in the protein rather than absolute enzymic activity.
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Affiliation(s)
- Ayesha S Rahman
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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50
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Cooper SM, Cox RJ, Crosby J, Crump MP, Hothersall J, Laosripaiboon W, Simpson TJ, Thomas CM. Mupirocin W, a novel pseudomonic acid produced by targeted mutation of the mupirocin biosynthetic gene cluster. Chem Commun (Camb) 2005:1179-81. [PMID: 15726184 DOI: 10.1039/b414781b] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mutation of the mupW gene in the mupirocin biosynthetic gene cluster in Pseudomonas fluorescens results in efficient production of a novel pseudomonic acid metabolite, mupirocin W, which lacks the characteristic tetrahydropyran ring, and reveals the role of the mupW gene in pseudomonic acid biosynthesis.
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Affiliation(s)
- Sian M Cooper
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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