1
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Luo G, Ming T, Yang L, He L, Tao T, Wang Y. Modulators targeting protein-protein interactions in Mycobacterium tuberculosis. Microbiol Res 2024; 284:127675. [PMID: 38636239 DOI: 10.1016/j.micres.2024.127675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 04/20/2024]
Abstract
Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis), mainly transmitted through droplets to infect the lungs, and seriously affecting patients' health and quality of life. Clinically, anti-TB drugs often entail side effects and lack efficacy against resistant strains. Thus, the exploration and development of novel targeted anti-TB medications are imperative. Currently, protein-protein interactions (PPIs) offer novel avenues for anti-TB drug development, and the study of targeted modulators of PPIs in M. tuberculosis has become a prominent research focus. Furthermore, a comprehensive PPI network has been constructed using computational methods and bioinformatics tools. This network allows for a more in-depth analysis of the structural biology of PPIs and furnishes essential insights for the development of targeted small-molecule modulators. Furthermore, this article provides a detailed overview of the research progress and regulatory mechanisms of PPI modulators in M. tuberculosis, the causative agent of TB. Additionally, it summarizes potential targets for anti-TB drugs and discusses the prospects of existing PPI modulators.
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Affiliation(s)
- Guofeng Luo
- School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Tianqi Ming
- State Key Laboratory of Southwestern Chinese Medicine Resources, Department of Pharmacology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Luchuan Yang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Lei He
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Tao Tao
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Yanmei Wang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China.
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2
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Giese C, Puorger C, Ignatov O, Bečárová Z, Weber ME, Schärer MA, Capitani G, Glockshuber R. Stochastic chain termination in bacterial pilus assembly. Nat Commun 2023; 14:7718. [PMID: 38001074 PMCID: PMC10673952 DOI: 10.1038/s41467-023-43449-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
Adhesive type 1 pili from uropathogenic Escherichia coli strains are filamentous, supramolecular protein complexes consisting of a short tip fibrillum and a long, helical rod formed by up to several thousand copies of the major pilus subunit FimA. Here, we reconstituted the entire type 1 pilus rod assembly reaction in vitro, using all constituent protein subunits in the presence of the assembly platform FimD, and identified the so-far uncharacterized subunit FimI as an irreversible assembly terminator. We provide a complete, quantitative model of pilus rod assembly kinetics based on the measured rate constants of FimD-catalyzed subunit incorporation. The model reliably predicts the length distribution of assembled pilus rods as a function of the ratio between FimI and the main pilus subunit FimA and is fully consistent with the length distribution of membrane-anchored pili assembled in vivo. The results show that the natural length distribution of adhesive pili formed via the chaperone-usher pathway results from a stochastic chain termination reaction. In addition, we demonstrate that FimI contributes to anchoring the pilus to the outer membrane and report the crystal structures of (i) FimI in complex with the assembly chaperone FimC, (ii) the FimI-FimC complex bound to the N-terminal domain of FimD, and (iii) a ternary complex between FimI, FimA and FimC that provides structural insights on pilus assembly termination and pilus anchoring by FimI.
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Affiliation(s)
- Christoph Giese
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland.
| | - Chasper Puorger
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Institute for Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, 4132, Muttenz, Switzerland
| | - Oleksandr Ignatov
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- V.I. Grishchenko Clinic of Reproductive Medicine, Blahovishchenska st.25, 61052, Kharkiv, Ukraine
| | - Zuzana Bečárová
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Marco E Weber
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Martin A Schärer
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Guido Capitani
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, 8093, Zurich, Switzerland
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3
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Stocker C, Khatanbaatar T, Bressan L, Würth-Roderer K, Cordara G, Krengel U, Kast P. Novel exported fusion enzymes with chorismate mutase and cyclohexadienyl dehydratase activity: Shikimate pathway enzymes teamed up in no man's land. J Biol Chem 2023; 299:105161. [PMID: 37586588 PMCID: PMC10520331 DOI: 10.1016/j.jbc.2023.105161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/29/2023] [Accepted: 08/11/2023] [Indexed: 08/18/2023] Open
Abstract
Chorismate mutase (CM) and cyclohexadienyl dehydratase (CDT) catalyze two subsequent reactions in the intracellular biosynthesis of l-phenylalanine (Phe). Here, we report the discovery of novel and extremely rare bifunctional fusion enzymes, consisting of fused CM and CDT domains, which are exported from the cytoplasm. Such enzymes were found in only nine bacterial species belonging to non-pathogenic γ- or β-Proteobacteria. In γ-proteobacterial fusion enzymes, the CM domain is N-terminal to the CDT domain, whereas the order is inverted in β-Proteobacteria. The CM domains share 15% to 20% sequence identity with the AroQγ class CM holotype of Mycobacterium tuberculosis (∗MtCM), and the CDT domains 40% to 60% identity with the exported monofunctional enzyme of Pseudomonas aeruginosa (PheC). In vitro kinetics revealed a Km <7 μM, much lower than for ∗MtCM, whereas kinetic parameters are similar for CDT domains and PheC. There is no feedback inhibition of CM or CDT by the pathway's end product Phe, and no catalytic benefit of the domain fusion compared with engineered single-domain constructs. The fusion enzymes of Aequoribacter fuscus, Janthinobacterium sp. HH01, and Duganella sacchari were crystallized and their structures refined to 1.6, 1.7, and 2.4 Å resolution, respectively. Neither the crystal structures nor the size-exclusion chromatography show evidence for substrate channeling or higher oligomeric structure that could account for the cooperation of CM and CDT active sites. The genetic neighborhood with genes encoding transporter and substrate binding proteins suggests that these exported bifunctional fusion enzymes may participate in signaling systems rather than in the biosynthesis of Phe.
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Affiliation(s)
- Christian Stocker
- Laboratory of Organic Chemistry, D-CHAB, ETH Zurich, Zurich, Switzerland
| | | | - Luca Bressan
- Laboratory of Organic Chemistry, D-CHAB, ETH Zurich, Zurich, Switzerland
| | | | | | - Ute Krengel
- Department of Chemistry, University of Oslo, Oslo, Norway.
| | - Peter Kast
- Laboratory of Organic Chemistry, D-CHAB, ETH Zurich, Zurich, Switzerland.
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4
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Kleeorin Y, Russ WP, Rivoire O, Ranganathan R. Undersampling and the inference of coevolution in proteins. Cell Syst 2023; 14:210-219.e7. [PMID: 36693377 PMCID: PMC10911952 DOI: 10.1016/j.cels.2022.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 01/02/2022] [Accepted: 12/23/2022] [Indexed: 01/24/2023]
Abstract
Protein structure, function, and evolution depend on local and collective epistatic interactions between amino acids. A powerful approach to defining these interactions is to construct models of couplings between amino acids that reproduce the empirical statistics (frequencies and correlations) observed in sequences comprising a protein family. The top couplings are then interpreted. Here, we show that as currently implemented, this inference unequally represents epistatic interactions, a problem that fundamentally arises from limited sampling of sequences in the context of distinct scales at which epistasis occurs in proteins. We show that these issues explain the ability of current approaches to predict tertiary contacts between amino acids and the inability to obviously expose larger networks of functionally relevant, collectively evolving residues called sectors. This work provides a necessary foundation for more deeply understanding and improving evolution-based models of proteins.
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Affiliation(s)
- Yaakov Kleeorin
- Center for Physics of Evolving Systems, Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - William P Russ
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Olivier Rivoire
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, 75005 Paris, France.
| | - Rama Ranganathan
- Center for Physics of Evolving Systems, Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60637, USA; The Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
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5
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Thorbjørnsrud H, Bressan L, Khatanbaatar T, Carrer M, Würth-Roderer K, Cordara G, Kast P, Cascella M, Krengel U. What Drives Chorismate Mutase to Top Performance? Insights from a Combined In Silico and In Vitro Study. Biochemistry 2023; 62:782-796. [PMID: 36705397 PMCID: PMC9910054 DOI: 10.1021/acs.biochem.2c00635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Unlike typical chorismate mutases, the enzyme from Mycobacterium tuberculosis (MtCM) has only low activity on its own. Remarkably, its catalytic efficiency kcat/Km can be boosted more than 100-fold by complex formation with a partner enzyme. Recently, an autonomously fully active MtCM variant was generated using directed evolution, and its structure was solved by X-ray crystallography. However, key residues were involved in crystal contacts, challenging the functional interpretation of the structural changes. Here, we address these challenges by microsecond molecular dynamics simulations, followed up by additional kinetic and structural analyses of selected sets of specifically engineered enzyme variants. A comparison of wild-type MtCM with naturally and artificially activated MtCMs revealed the overall dynamic profiles of these enzymes as well as key interactions between the C-terminus and the active site loop. In the artificially evolved variant of this model enzyme, this loop is preorganized and stabilized by Pro52 and Asp55, two highly conserved residues in typical, highly active chorismate mutases. Asp55 stretches across the active site and helps to appropriately position active site residues Arg18 and Arg46 for catalysis. The role of Asp55 can be taken over by another acidic residue, if introduced at position 88 close to the C-terminus of MtCM, as suggested by molecular dynamics simulations and confirmed by kinetic investigations of engineered variants.
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Affiliation(s)
- Helen
V. Thorbjørnsrud
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway
| | - Luca Bressan
- Laboratory
of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Tamjidmaa Khatanbaatar
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway
| | - Manuel Carrer
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway
| | | | - Gabriele Cordara
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway
| | - Peter Kast
- Laboratory
of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland,
| | - Michele Cascella
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway,
| | - Ute Krengel
- Department
of Chemistry, University of Oslo, Oslo 0315, NO, Norway,Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Oslo 0315, NO, Norway,
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6
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Fahrig-Kamarauskait J, Würth-Roderer K, Thorbjørnsrud HV, Mailand S, Krengel U, Kast P. Evolving the naturally compromised chorismate mutase from Mycobacterium tuberculosis to top performance. J Biol Chem 2020; 295:17514-17534. [PMID: 33453995 PMCID: PMC7762937 DOI: 10.1074/jbc.ra120.014924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/08/2020] [Indexed: 11/06/2022] Open
Abstract
Chorismate mutase (CM), an essential enzyme at the branch-point of the shikimate pathway, is required for the biosynthesis of phenylalanine and tyrosine in bacteria, archaea, plants, and fungi. MtCM, the CM from Mycobacterium tuberculosis, has less than 1% of the catalytic efficiency of a typical natural CM and requires complex formation with 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase for high activity. To explore the full potential of MtCM for catalyzing its native reaction, we applied diverse iterative cycles of mutagenesis and selection, thereby raising kcat/Km 270-fold to 5 × 105m−1s−1, which is even higher than for the complex. Moreover, the evolutionarily optimized autonomous MtCM, which had 11 of its 90 amino acids exchanged, was stabilized compared with its progenitor, as indicated by a 9 °C increase in melting temperature. The 1.5 Å crystal structure of the top-evolved MtCM variant reveals the molecular underpinnings of this activity boost. Some acquired residues (e.g. Pro52 and Asp55) are conserved in naturally efficient CMs, but most of them lie beyond the active site. Our evolutionary trajectories reached a plateau at the level of the best natural enzymes, suggesting that we have exhausted the potential of MtCM. Taken together, these findings show that the scaffold of MtCM, which naturally evolved for mediocrity to enable inter-enzyme allosteric regulation of the shikimate pathway, is inherently capable of high activity.
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Affiliation(s)
| | | | | | - Susanne Mailand
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland
| | - Ute Krengel
- Department of Chemistry, University of Oslo, Oslo, Norway.
| | - Peter Kast
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland.
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7
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Russ WP, Figliuzzi M, Stocker C, Barrat-Charlaix P, Socolich M, Kast P, Hilvert D, Monasson R, Cocco S, Weigt M, Ranganathan R. An evolution-based model for designing chorismate mutase enzymes. Science 2020; 369:440-445. [PMID: 32703877 DOI: 10.1126/science.aba3304] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 05/13/2020] [Indexed: 02/02/2023]
Abstract
The rational design of enzymes is an important goal for both fundamental and practical reasons. Here, we describe a process to learn the constraints for specifying proteins purely from evolutionary sequence data, design and build libraries of synthetic genes, and test them for activity in vivo using a quantitative complementation assay. For chorismate mutase, a key enzyme in the biosynthesis of aromatic amino acids, we demonstrate the design of natural-like catalytic function with substantial sequence diversity. Further optimization focuses the generative model toward function in a specific genomic context. The data show that sequence-based statistical models suffice to specify proteins and provide access to an enormous space of functional sequences. This result provides a foundation for a general process for evolution-based design of artificial proteins.
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Affiliation(s)
- William P Russ
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Matteo Figliuzzi
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie Computationnelle and Quantitative, Paris, France
| | | | - Pierre Barrat-Charlaix
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie Computationnelle and Quantitative, Paris, France.,Biozentrum, University of Basel, Basel, Switzerland
| | - Michael Socolich
- Center for Physics of Evolving Systems, Biochemistry and Molecular Biology and the Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Peter Kast
- Laboratory of Organic Chemistry, ETH Zurich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zurich, Switzerland
| | - Remi Monasson
- Laboratoire de Physique de l'Ecole Normale Supérieure, PSL and CNRS, Paris, France
| | - Simona Cocco
- Laboratoire de Physique de l'Ecole Normale Supérieure, PSL and CNRS, Paris, France
| | - Martin Weigt
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Laboratoire de Biologie Computationnelle and Quantitative, Paris, France.
| | - Rama Ranganathan
- Center for Physics of Evolving Systems, Biochemistry and Molecular Biology and the Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA.
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8
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Debon A, Pott M, Obexer R, Green AP, Friedrich L, Griffiths AD, Hilvert D. Ultrahigh-throughput screening enables efficient single-round oxidase remodelling. Nat Catal 2019. [DOI: 10.1038/s41929-019-0340-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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9
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Burschowsky D, Thorbjørnsrud HV, Heim JB, Fahrig-Kamarauskaitė JR, Würth-Roderer K, Kast P, Krengel U. Inter-Enzyme Allosteric Regulation of Chorismate Mutase in Corynebacterium glutamicum: Structural Basis of Feedback Activation by Trp. Biochemistry 2017; 57:557-573. [PMID: 29178787 DOI: 10.1021/acs.biochem.7b01018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Corynebacterium glutamicum is widely used for the industrial production of amino acids, nucleotides, and vitamins. The shikimate pathway enzymes DAHP synthase (CgDS, Cg2391) and chorismate mutase (CgCM, Cgl0853) play a key role in the biosynthesis of aromatic compounds. Here we show that CgCM requires the formation of a complex with CgDS to achieve full activity, and that both CgCM and CgDS are feedback regulated by aromatic amino acids binding to CgDS. Kinetic analysis showed that Phe and Tyr inhibit CgCM activity by inter-enzyme allostery, whereas binding of Trp to CgDS strongly activates CgCM. Mechanistic insights were gained from crystal structures of the CgCM homodimer, tetrameric CgDS, and the heterooctameric CgCM-CgDS complex, refined to 1.1, 2.5, and 2.2 Å resolution, respectively. Structural details from the allosteric binding sites reveal that DAHP synthase is recruited as the dominant regulatory platform to control the shikimate pathway, similar to the corresponding enzyme complex from Mycobacterium tuberculosis.
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Affiliation(s)
| | | | - Joel B Heim
- Department of Chemistry, University of Oslo , NO-0315 Oslo, Norway
| | | | | | - Peter Kast
- Laboratory of Organic Chemistry, ETH Zurich , CH-8093 Zurich, Switzerland
| | - Ute Krengel
- Department of Chemistry, University of Oslo , NO-0315 Oslo, Norway
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10
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Obexer R, Pott M, Zeymer C, Griffiths AD, Hilvert D. Efficient laboratory evolution of computationally designed enzymes with low starting activities using fluorescence-activated droplet sorting. Protein Eng Des Sel 2016; 29:355-66. [DOI: 10.1093/protein/gzw032] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 06/21/2016] [Indexed: 11/14/2022] Open
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11
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Remote Control by Inter-Enzyme Allostery: A Novel Paradigm for Regulation of the Shikimate Pathway. J Mol Biol 2016; 428:1237-1255. [DOI: 10.1016/j.jmb.2016.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 12/22/2015] [Accepted: 01/02/2016] [Indexed: 11/16/2022]
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12
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Blackmore NJ, Nazmi AR, Hutton RD, Webby MN, Baker EN, Jameson GB, Parker EJ. Complex Formation between Two Biosynthetic Enzymes Modifies the Allosteric Regulatory Properties of Both: AN EXAMPLE OF MOLECULAR SYMBIOSIS. J Biol Chem 2015; 290:18187-18198. [PMID: 26032422 DOI: 10.1074/jbc.m115.638700] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 11/06/2022] Open
Abstract
Allostery, where remote ligand binding alters protein function, is essential for the control of metabolism. Here, we have identified a highly sophisticated allosteric response that allows complex control of the pathway for aromatic amino acid biosynthesis in the pathogen Mycobacterium tuberculosis. This response is mediated by an enzyme complex formed by two pathway enzymes: chorismate mutase (CM) and 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS). Whereas both enzymes are active in isolation, the catalytic activity of both enzymes is enhanced, and in particular that of the much smaller CM is greatly enhanced (by 120-fold), by formation of a hetero-octameric complex between CM and DAH7PS. Moreover, on complex formation M. tuberculosis CM, which has no allosteric response on its own, acquires allosteric behavior to facilitate its own regulatory needs by directly appropriating and partly reconfiguring the allosteric machinery that provides a synergistic allosteric response in DAH7PS. Kinetic and analytical ultracentrifugation experiments demonstrate that allosteric binding of phenylalanine specifically promotes hetero-octameric complex dissociation, with concomitant reduction of CM activity. Together, DAH7PS and CM from M. tuberculosis provide exquisite control of aromatic amino acid biosynthesis, not only controlling flux into the start of the pathway, but also directing the pathway intermediate chorismate into either Phe/Tyr or Trp biosynthesis.
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Affiliation(s)
- Nicola J Blackmore
- Maurice Wilkins Centre and Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Ali Reza Nazmi
- Maurice Wilkins Centre and Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Richard D Hutton
- Maurice Wilkins Centre and Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Melissa N Webby
- Maurice Wilkins Centre and Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Edward N Baker
- Maurice Wilkins Centre and School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Geoffrey B Jameson
- Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand.
| | - Emily J Parker
- Maurice Wilkins Centre and Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand.
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