1
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Buda K, Miton CM, Fan XC, Tokuriki N. Molecular determinants of protein evolvability. Trends Biochem Sci 2023; 48:751-760. [PMID: 37330341 DOI: 10.1016/j.tibs.2023.05.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/18/2023] [Accepted: 05/23/2023] [Indexed: 06/19/2023]
Abstract
The plethora of biological functions that sustain life is rooted in the remarkable evolvability of proteins. An emerging view highlights the importance of a protein's initial state in dictating evolutionary success. A deeper comprehension of the mechanisms that govern the evolvability of these initial states can provide invaluable insights into protein evolution. In this review, we describe several molecular determinants of protein evolvability, unveiled by experimental evolution and ancestral sequence reconstruction studies. We further discuss how genetic variation and epistasis can promote or constrain functional innovation and suggest putative underlying mechanisms. By establishing a clear framework for these determinants, we provide potential indicators enabling the forecast of suitable evolutionary starting points and delineate molecular mechanisms in need of deeper exploration.
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Affiliation(s)
- Karol Buda
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Charlotte M Miton
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Xingyu Cara Fan
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, Canada.
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2
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Alejaldre L, Lemay-St-Denis C, Pelletier JN, Quaglia D. Tuning Selectivity in CalA Lipase: Beyond Tunnel Engineering. Biochemistry 2023; 62:396-409. [PMID: 36580299 PMCID: PMC9851156 DOI: 10.1021/acs.biochem.2c00513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/15/2022] [Indexed: 12/30/2022]
Abstract
Engineering studies of Candida (Pseudozyma) antarctica lipase A (CalA) have demonstrated the potential of this enzyme in the selective hydrolysis of fatty acid esters of different chain lengths. CalA has been shown to bind substrates preferentially through an acyl-chain binding tunnel accessed via the hydrolytic active site; it has also been shown that selectivity for substrates of longer or shorter chain length can be tuned, for instance by modulating steric hindrance within the tunnel. Here we demonstrate that, whereas the tunnel region is certainly of paramount importance for substrate recognition, residues in distal regions of the enzyme can also modulate substrate selectivity. To this end, we investigate variants that carry one or more substitutions within the substrate tunnel as well as in distal regions. Combining experimental determination of the substrate selectivity using natural and synthetic substrates with computational characterization of protein dynamics and of tunnels, we deconvolute the effect of key substitutions and demonstrate that epistatic interactions contribute to procuring selectivity toward either long-chain or short/medium-chain fatty acid esters. We demonstrate that various mechanisms contribute to the diverse selectivity profiles, ranging from reshaping tunnel morphology and tunnel stabilization to obstructing the main substrate-binding tunnel, highlighting the dynamic nature of the substrate-binding region. This work provides important insights into the versatility of this robust lipase toward diverse applications.
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Affiliation(s)
- Lorea Alejaldre
- PROTEO,
The Québec Network for Research on Protein, Function, Engineering
and Applications, https://proteo.ca/en/
- CGCC, Center
in Green Chemistry and Catalysis, Montréal, QC, CanadaG1V 0A6
- Department
of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, CanadaH3T 1J4
| | - Claudèle Lemay-St-Denis
- PROTEO,
The Québec Network for Research on Protein, Function, Engineering
and Applications, https://proteo.ca/en/
- CGCC, Center
in Green Chemistry and Catalysis, Montréal, QC, CanadaG1V 0A6
- Department
of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, CanadaH3T 1J4
| | - Joelle N. Pelletier
- PROTEO,
The Québec Network for Research on Protein, Function, Engineering
and Applications, https://proteo.ca/en/
- CGCC, Center
in Green Chemistry and Catalysis, Montréal, QC, CanadaG1V 0A6
- Department
of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, CanadaH3T 1J4
- Department
of Chemistry, Université de Montréal, Montréal, QC, CanadaH2V 0B3
| | - Daniela Quaglia
- PROTEO,
The Québec Network for Research on Protein, Function, Engineering
and Applications, https://proteo.ca/en/
- CGCC, Center
in Green Chemistry and Catalysis, Montréal, QC, CanadaG1V 0A6
- Department
of Chemistry, Université de Montréal, Montréal, QC, CanadaH2V 0B3
- Department
of Chemistry, Carleton University, Ottawa, ON, CanadaK1S 5B6
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3
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Galenkamp NS, Maglia G. Single-Molecule Sampling of Dihydrofolate Reductase Shows Kinetic Pauses and an Endosteric Effect Linked to Catalysis. ACS Catal 2022; 12:1228-1236. [PMID: 35096468 PMCID: PMC8787752 DOI: 10.1021/acscatal.1c04388] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/13/2021] [Indexed: 12/21/2022]
Abstract
![]()
The ability to sample multiple reactions
on the same single enzyme
is important to link rare intermediates with catalysis and to unravel
the role of conformational changes. Despite decades of efforts, however,
the single-molecule characterization of nonfluorogenic enzymes during
multiple catalytic turnovers has been elusive. Here, we show that
nanopore currents allow sampling the dynamic exchange between five
structural intermediates during E. coli dihydrofolate reductase (DHFR) catalysis. We found that an endosteric
effect promotes the binding of the substrate to the enzyme with a
specific hierarchy. The chemical step then switched the enzyme from
the closed to the occluded conformation, which in turn promotes the
release of the reduced cofactor NADP+. Unexpectedly, only
a few reactive complexes lead to catalysis. Furthermore, second-long
catalytic pauses were observed, possibly reflecting an off-path conformation
generated during the reaction. Finally, the free energy from multiple
cofactor binding events were required to release the product and switch
DHFR back to the reactive conformer. This catalytic fueled concerted
mechanism is likely to have evolved to improve the catalytic efficiency
of DHFR under the high concentrations of NADP+ in E. coli and might be a general feature for complex
enzymatic reactions where the binding and release of the products
must be tightly controlled.
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Affiliation(s)
- Nicole Stéphanie Galenkamp
- Groningen Biomolecular Sciences and Biotechnology (GBB) Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Giovanni Maglia
- Groningen Biomolecular Sciences and Biotechnology (GBB) Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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4
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Elings W, Chikunova A, van Zanten DB, Drenth R, Ahmad MUD, Blok AJ, Timmer M, Perrakis A, Ubbink M. Two β-Lactamase Variants with Reduced Clavulanic Acid Inhibition Display Different Millisecond Dynamics. Antimicrob Agents Chemother 2021; 65:e0262820. [PMID: 34031049 PMCID: PMC8284444 DOI: 10.1128/aac.02628-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 05/07/2021] [Indexed: 11/20/2022] Open
Abstract
The β-lactamase of Mycobacterium tuberculosis, BlaC, is susceptible to inhibition by clavulanic acid. The ability of this enzyme to escape inhibition through mutation was probed using error-prone PCR combined with functional screening in Escherichia coli. The variant that was found to confer the most inhibitor resistance, K234R, as well as variant G132N that was found previously were characterized using X-ray crystallography and nuclear magnetic resonance (NMR) relaxation experiments to probe structural and dynamic properties. The G132N mutant exists in solution in two almost equally populated conformations that exchange with a rate of ca. 88 s-1. The conformational change affects a broad region of the enzyme. The crystal structure reveals that the Asn132 side chain forces the peptide bond between Ser104 and Ile105 in a cis-conformation. The crystal structure suggests multiple conformations for several side chains (e.g., Ser104 and Ser130) and a short loop (positions 214 to 216). In the K234R mutant, the active-site dynamics are significantly diminished with respect to the wild-type enzyme. These results show that multiple evolutionary routes are available to increase inhibitor resistance in BlaC and that active-site dynamics on the millisecond time scale are not required for catalytic function.
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Affiliation(s)
- Wouter Elings
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | | | | | - Ralphe Drenth
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Misbha Ud Din Ahmad
- Division of Biochemistry, the Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, Amsterdam, The Netherlands
| | - Anneloes J. Blok
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Monika Timmer
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Anastassis Perrakis
- Division of Biochemistry, the Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, Amsterdam, The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
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5
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Paquet-Côté PA, Alejaldre L, Lapointe Verreault C, Gobeil SMC, Lamoureux R, Bédard L, Normandeau CO, Lemay-St-Denis C, Pelletier JN, Voyer N. Development of sulfahydantoin derivatives as β-lactamase inhibitors. Bioorg Med Chem Lett 2021; 35:127781. [PMID: 33422604 DOI: 10.1016/j.bmcl.2021.127781] [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: 12/07/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 11/16/2022]
Abstract
Sulfahydantoin-based molecules may provide a means to counteract antibiotic resistance, which is on the rise. These molecules may act as inhibitors of β-lactamase enzymes, which are key in some resistance mechanisms. In this paper, we report on the synthesis of 6 novel sulfahydantoin derivatives by the key reaction of chlorosulfonyl isocyanate to form α-amino acid derived sulfamides, and their cyclization into sulfahydantoins. The synthesis is rapid and provides the target compounds in 8 steps. We investigated their potential as β-lactamase inhibitors using two common Class A β-lactamases, TEM-1 and the prevalent extended-spectrum TEM-15. Two compounds, 3 and 6, show substantial inhibition of the β-lactamases with IC50 values between 130 and 510 μM and inferred Ki values between 32 and 55 μM.
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Affiliation(s)
| | - Lorea Alejaldre
- Département de biochimie and PROTEO, Université de Montréal, Montréal H3C 3J7, Canada
| | | | - Sophie M C Gobeil
- Département de biochimie and PROTEO, Université de Montréal, Montréal H3C 3J7, Canada
| | - Rosalie Lamoureux
- Département de Chimie and PROTEO, Université Laval, 1045 avenue de la Médecine, Québec G1V 0A6, Canada
| | - Laurie Bédard
- Département de Chimie and PROTEO, Université Laval, 1045 avenue de la Médecine, Québec G1V 0A6, Canada
| | | | | | - Joelle N Pelletier
- Département de biochimie and PROTEO, Université de Montréal, Montréal H3C 3J7, Canada; Département de chimie, Université de Montréal, Montréal H3C 3J7, Canada
| | - Normand Voyer
- Département de Chimie and PROTEO, Université Laval, 1045 avenue de la Médecine, Québec G1V 0A6, Canada.
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6
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Alejaldre L, Lemay-St-Denis C, Perez Lopez C, Sancho Jodar F, Guallar V, Pelletier JN. Known Evolutionary Paths Are Accessible to Engineered ß-Lactamases Having Altered Protein Motions at the Timescale of Catalytic Turnover. Front Mol Biosci 2020; 7:599298. [PMID: 33330628 PMCID: PMC7716773 DOI: 10.3389/fmolb.2020.599298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/23/2020] [Indexed: 11/26/2022] Open
Abstract
The evolution of new protein functions is dependent upon inherent biophysical features of proteins. Whereas, it has been shown that changes in protein dynamics can occur in the course of directed molecular evolution trajectories and contribute to new function, it is not known whether varying protein dynamics modify the course of evolution. We investigate this question using three related ß-lactamases displaying dynamics that differ broadly at the slow timescale that corresponds to catalytic turnover yet have similar fast dynamics, thermal stability, catalytic, and substrate recognition profiles. Introduction of substitutions E104K and G238S, that are known to have a synergistic effect on function in the parent ß-lactamase, showed similar increases in catalytic efficiency toward cefotaxime in the related ß-lactamases. Molecular simulations using Protein Energy Landscape Exploration reveal that this results from stabilizing the catalytically-productive conformations, demonstrating the dominance of the synergistic effect of the E014K and G238S substitutions in vitro in contexts that vary in terms of sequence and dynamics. Furthermore, three rounds of directed molecular evolution demonstrated that known cefotaximase-enhancing mutations were accessible regardless of the differences in dynamics. Interestingly, specific sequence differences between the related ß-lactamases were shown to have a higher effect in evolutionary outcomes than did differences in dynamics. Overall, these ß-lactamase models show tolerance to protein dynamics at the timescale of catalytic turnover in the evolution of a new function.
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Affiliation(s)
- Lorea Alejaldre
- Biochemistry Department, Université de Montréal, Montréal, QC, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Quebec City, QC, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC, Canada
| | - Claudèle Lemay-St-Denis
- Biochemistry Department, Université de Montréal, Montréal, QC, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Quebec City, QC, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC, Canada
| | | | | | - Victor Guallar
- Barcelona Supercomputing Center, Barcelona, Spain
- ICREA: Institució Catalana de Recerca i Estudis Avancats, Barcelona, Spain
| | - Joelle N. Pelletier
- Biochemistry Department, Université de Montréal, Montréal, QC, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Quebec City, QC, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC, Canada
- Chemistry Department, Université de Montréal, Montréal, QC, Canada
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7
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Osuna S. The challenge of predicting distal active site mutations in computational enzyme design. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2020. [DOI: 10.1002/wcms.1502] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Sílvia Osuna
- CompBioLab group, Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química Universitat de Girona Girona Spain
- ICREA Barcelona Spain
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8
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Yang G, Miton CM, Tokuriki N. A mechanistic view of enzyme evolution. Protein Sci 2020; 29:1724-1747. [PMID: 32557882 PMCID: PMC7380680 DOI: 10.1002/pro.3901] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 12/15/2022]
Abstract
New enzyme functions often evolve through the recruitment and optimization of latent promiscuous activities. How do mutations alter the molecular architecture of enzymes to enhance their activities? Can we infer general mechanisms that are common to most enzymes, or does each enzyme require a unique optimization process? The ability to predict the location and type of mutations necessary to enhance an enzyme's activity is critical to protein engineering and rational design. In this review, via the detailed examination of recent studies that have shed new light on the molecular changes underlying the optimization of enzyme function, we provide a mechanistic perspective of enzyme evolution. We first present a global survey of the prevalence of activity-enhancing mutations and their distribution within protein structures. We then delve into the molecular solutions that mediate functional optimization, specifically highlighting several common mechanisms that have been observed across multiple examples. As distinct protein sequences encounter different evolutionary bottlenecks, different mechanisms are likely to emerge along evolutionary trajectories toward improved function. Identifying the specific mechanism(s) that need to be improved upon, and tailoring our engineering efforts to each sequence, may considerably improve our chances to succeed in generating highly efficient catalysts in the future.
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Affiliation(s)
- Gloria Yang
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Charlotte M. Miton
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Nobuhiko Tokuriki
- Michael Smith LaboratoriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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9
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Crean RM, Gardner JM, Kamerlin SCL. Harnessing Conformational Plasticity to Generate Designer Enzymes. J Am Chem Soc 2020; 142:11324-11342. [PMID: 32496764 PMCID: PMC7467679 DOI: 10.1021/jacs.0c04924] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Indexed: 02/08/2023]
Abstract
Recent years have witnessed an explosion of interest in understanding the role of conformational dynamics both in the evolution of new enzymatic activities from existing enzymes and in facilitating the emergence of enzymatic activity de novo on scaffolds that were previously non-catalytic. There are also an increasing number of examples in the literature of targeted engineering of conformational dynamics being successfully used to alter enzyme selectivity and activity. Despite the obvious importance of conformational dynamics to both enzyme function and evolvability, many (although not all) computational design approaches still focus either on pure sequence-based approaches or on using structures with limited flexibility to guide the design. However, there exist a wide variety of computational approaches that can be (re)purposed to introduce conformational dynamics as a key consideration in the design process. Coupled with laboratory evolution and more conventional existing sequence- and structure-based approaches, these techniques provide powerful tools for greatly expanding the protein engineering toolkit. This Perspective provides an overview of evolutionary studies that have dissected the role of conformational dynamics in facilitating the emergence of novel enzymes, as well as advances in computational approaches that allow one to target conformational dynamics as part of enzyme design. Harnessing conformational dynamics in engineering studies is a powerful paradigm with which to engineer the next generation of designer biocatalysts.
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Affiliation(s)
- Rory M. Crean
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Jasmine M. Gardner
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Shina C. L. Kamerlin
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
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10
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β-Lactamase of Mycobacterium tuberculosis Shows Dynamics in the Active Site That Increase upon Inhibitor Binding. Antimicrob Agents Chemother 2020; 64:AAC.02025-19. [PMID: 31871087 DOI: 10.1128/aac.02025-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022] Open
Abstract
The Mycobacterium tuberculosis β-lactamase BlaC is a broad-spectrum β-lactamase that can convert a range of β-lactam antibiotics. Enzymes with low specificity are expected to exhibit active-site flexibility. To probe the motions in BlaC, we studied the dynamic behavior in solution using nuclear magnetic resonance (NMR) spectroscopy. 15N relaxation experiments show that BlaC is mostly rigid on the pico- to nanosecond timescale. Saturation transfer experiments indicate that also on the high-millisecond timescale BlaC is not dynamic. Using relaxation dispersion experiments, clear evidence was obtained for dynamics in the low-millisecond range, with an exchange rate of ca. 860 s-1 The dynamic amide groups are localized in the active site. Upon formation of an adduct with the inhibitor avibactam, extensive line broadening occurs, indicating an increase in magnitude of the active-site dynamics. Furthermore, the rate of the motions increases significantly. Upon reaction with the inhibitor clavulanic acid, similar line broadening is accompanied by duplication of NMR signals, indicative of at least one additional, slower exchange process (exchange rate, k ex, of <100 s-1), while for this inhibitor also loss of pico- to nanosecond timescale rigidity is observed for some amides in the α domain. Possible sources of the observed dynamics, such as motions in the omega loop and rearrangements of active-site residues, are discussed. The increase in dynamics upon ligand binding argues against a model of inhibitor binding through conformational selection. Rather, the induced dynamics may serve to maximize the likelihood of sampling the optimal conformation for hydrolysis of the bound ligand.
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11
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Mayorov A, Dal Peraro M, Abriata LA. Active Site-Induced Evolutionary Constraints Follow Fold Polarity Principles in Soluble Globular Enzymes. Mol Biol Evol 2020; 36:1728-1733. [PMID: 31004173 DOI: 10.1093/molbev/msz096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A recent analysis of evolutionary rates in >500 globular soluble enzymes revealed pervasive conservation gradients toward catalytic residues. By looking at amino acid preference profiles rather than evolutionary rates in the same data set, we quantified the effects of active sites on site-specific constraints for physicochemical traits. We found that conservation gradients respond to constraints for polarity, hydrophobicity, flexibility, rigidity and structure in ways consistent with fold polarity principles; while sites far from active sites seem to experience no physicochemical constraint, rather being highly variable and favoring amino acids of low metabolic cost. Globally, our results highlight that amino acid variation contains finer information about protein structure than usually regarded in evolutionary models, and that this information is retrievable automatically with simple fits. We propose that analyses of the kind presented here incorporated into models of protein evolution should allow for better description of the physical chemistry that underlies molecular evolution.
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Affiliation(s)
- Alexander Mayorov
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Matteo Dal Peraro
- Laboratory for Biomolecular Modeling, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Luciano A Abriata
- Laboratory for Biomolecular Modeling, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland.,Protein Production and Structure Core Facility, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland
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12
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The Structural Dynamics of Engineered β-Lactamases Vary Broadly on Three Timescales yet Sustain Native Function. Sci Rep 2019; 9:6656. [PMID: 31040324 PMCID: PMC6491436 DOI: 10.1038/s41598-019-42866-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/10/2019] [Indexed: 12/20/2022] Open
Abstract
Understanding the principles of protein dynamics will help guide engineering of protein function: altering protein motions may be a barrier to success or may be an enabling tool for protein engineering. The impact of dynamics on protein function is typically reported over a fraction of the full scope of motional timescales. If motional patterns vary significantly at different timescales, then only by monitoring motions broadly will we understand the impact of protein dynamics on engineering functional proteins. Using an integrative approach combining experimental and in silico methodologies, we elucidate protein dynamics over the entire span of fast to slow timescales (ps to ms) for a laboratory-engineered system composed of five interrelated β-lactamases: two natural homologs and three laboratory-recombined variants. Fast (ps-ns) and intermediate (ns-µs) dynamics were mostly conserved. However, slow motions (µs-ms) were few and conserved in the natural homologs yet were numerous and widely dispersed in their recombinants. Nonetheless, modified slow dynamics were functionally tolerated. Crystallographic B-factors from high-resolution X-ray structures were partly predictive of the conserved motions but not of the new slow motions captured in our solution studies. Our inspection of protein dynamics over a continuous range of timescales vividly illustrates the complexity of dynamic impacts of protein engineering as well as the functional tolerance of an engineered enzyme system to new slow motions.
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13
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Abstract
The catalytic activities of enzymes are typically associated with their unique structures. However, structural dynamics may also play a functional role in enzyme catalysis. In support of this idea, Narayanan et al. (2018) show in this issue of Structure that enzymes are characterized by the presence of evolutionarily conserved dynamic traits.
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14
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Molecular modeling of conformational dynamics and its role in enzyme evolution. Curr Opin Struct Biol 2018; 52:50-57. [PMID: 30205262 DOI: 10.1016/j.sbi.2018.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/20/2018] [Indexed: 12/19/2022]
Abstract
With increasing computational power, biomolecular simulations have become an invaluable tool for understanding enzyme mechanisms and the origins of enzyme catalysis. More recently, computational studies have started to focus on understanding how enzyme activity itself evolves, both in terms of enhancing the native or new activities on existing enzyme scaffolds, or completely de novo on previously non-catalytic scaffolds. In this context, both experiment and molecular modeling provided strong evidence for an important role of conformational dynamics in the evolution of enzyme functions. This contribution will present a brief overview of the current state of the art for computationally exploring enzyme conformational dynamics in enzyme evolution, and, using several showcase studies, illustrate the ways molecular modeling can be used to shed light on how enzyme function evolves, at the most fundamental molecular level.
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15
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Maria-Solano MA, Serrano-Hervás E, Romero-Rivera A, Iglesias-Fernández J, Osuna S. Role of conformational dynamics in the evolution of novel enzyme function. Chem Commun (Camb) 2018; 54:6622-6634. [PMID: 29780987 PMCID: PMC6009289 DOI: 10.1039/c8cc02426j] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/10/2018] [Indexed: 12/26/2022]
Abstract
The free energy landscape concept that describes enzymes as an ensemble of differently populated conformational sub-states in dynamic equilibrium is key for evaluating enzyme activity, enantioselectivity, and specificity. Mutations introduced in the enzyme sequence can alter the populations of the pre-existing conformational states, thus strongly modifying the enzyme ability to accommodate alternative substrates, revert its enantiopreferences, and even increase the activity for some residual promiscuous reactions. In this feature article, we present an overview of the current experimental and computational strategies to explore the conformational free energy landscape of enzymes. We provide a series of recent publications that highlight the key role of conformational dynamics for the enzyme evolution towards new functions and substrates, and provide some perspectives on how conformational dynamism should be considered in future computational enzyme design protocols.
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Affiliation(s)
- Miguel A. Maria-Solano
- CompBioLab Group
, Institut de Química Computacional i Catàlisi and Departament de Química
, Universitat de Girona
,
Carrer Maria Aurèlia Capmany, 69
, 17003 Girona
, Catalonia
, Spain
.
| | - Eila Serrano-Hervás
- CompBioLab Group
, Institut de Química Computacional i Catàlisi and Departament de Química
, Universitat de Girona
,
Carrer Maria Aurèlia Capmany, 69
, 17003 Girona
, Catalonia
, Spain
.
| | - Adrian Romero-Rivera
- CompBioLab Group
, Institut de Química Computacional i Catàlisi and Departament de Química
, Universitat de Girona
,
Carrer Maria Aurèlia Capmany, 69
, 17003 Girona
, Catalonia
, Spain
.
| | - Javier Iglesias-Fernández
- CompBioLab Group
, Institut de Química Computacional i Catàlisi and Departament de Química
, Universitat de Girona
,
Carrer Maria Aurèlia Capmany, 69
, 17003 Girona
, Catalonia
, Spain
.
| | - Sílvia Osuna
- CompBioLab Group
, Institut de Química Computacional i Catàlisi and Departament de Química
, Universitat de Girona
,
Carrer Maria Aurèlia Capmany, 69
, 17003 Girona
, Catalonia
, Spain
.
- ICREA
,
Pg. Lluís Companys 23
, 08010 Barcelona
, Spain
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16
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Campbell EC, Correy GJ, Mabbitt PD, Buckle AM, Tokuriki N, Jackson CJ. Laboratory evolution of protein conformational dynamics. Curr Opin Struct Biol 2018; 50:49-57. [DOI: 10.1016/j.sbi.2017.09.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
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17
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Conservation of Dynamics Associated with Biological Function in an Enzyme Superfamily. Structure 2018; 26:426-436.e3. [PMID: 29478822 DOI: 10.1016/j.str.2018.01.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/06/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022]
Abstract
Enzyme superfamily members that share common chemical and/or biological functions also share common features. While the role of structure is well characterized, the link between enzyme function and dynamics is not well understood. We present a systematic characterization of intrinsic dynamics of over 20 members of the pancreatic-type RNase superfamily, which share a common structural fold. This study is motivated by the fact that the range of chemical activity as well as molecular motions of RNase homologs spans over 105 folds. Dynamics was characterized using a combination of nuclear magnetic resonance experiments and computer simulations. Phylogenetic clustering led to the grouping of sequences into functionally distinct subfamilies. Detailed characterization of the diverse RNases showed conserved dynamical traits for enzymes within subfamilies. These results suggest that selective pressure for the conservation of dynamical behavior, among other factors, may be linked to the distinct chemical and biological functions in an enzyme superfamily.
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18
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Romero-Rivera A, Garcia-Borràs M, Osuna S. Role of Conformational Dynamics in the Evolution of Retro-Aldolase Activity. ACS Catal 2017; 7:8524-8532. [PMID: 29226011 PMCID: PMC5716449 DOI: 10.1021/acscatal.7b02954] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/19/2017] [Indexed: 12/19/2022]
Abstract
![]()
Enzymes exist as
ensembles of conformations that are important
for function. Tuning these populations of conformational states through
mutation enables evolution toward additional activities. Here we computationally
evaluate the population shifts induced by distal and active site mutations
in a family of computationally designed and experimentally optimized
retro-aldolases. The conformational landscape of these enzymes was
significantly altered during evolution, as pre-existing catalytically
active conformational substates became major states in the most evolved
variants. We further demonstrate that key residues responsible for
these substate conversions can be predicted computationally. Significantly,
the identified residues coincide with those positions mutated in the
laboratory evolution experiments. This study establishes that distal
mutations that affect enzyme catalytic activity can be predicted computationally
and thus provides the enzyme (re)design field with a rational strategy
to determine promising sites for enhancing activity through mutation.
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Affiliation(s)
- Adrian Romero-Rivera
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, 17003 Girona, Spain
| | - Marc Garcia-Borràs
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, 17003 Girona, Spain
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), 607 Charles E. Young Drive, Los Angeles, California 90095, United States
| | - Sílvia Osuna
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, 17003 Girona, Spain
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19
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Warshel A, Bora RP. Perspective: Defining and quantifying the role of dynamics in enzyme catalysis. J Chem Phys 2017; 144:180901. [PMID: 27179464 DOI: 10.1063/1.4947037] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Enzymes control chemical reactions that are key to life processes, and allow them to take place on the time scale needed for synchronization between the relevant reaction cycles. In addition to general interest in their biological roles, these proteins present a fundamental scientific puzzle, since the origin of their tremendous catalytic power is still unclear. While many different hypotheses have been put forward to rationalize this, one of the proposals that has become particularly popular in recent years is the idea that dynamical effects contribute to catalysis. Here, we present a critical review of the dynamical idea, considering all reasonable definitions of what does and does not qualify as a dynamical effect. We demonstrate that no dynamical effect (according to these definitions) has ever been experimentally shown to contribute to catalysis. Furthermore, the existence of non-negligible dynamical contributions to catalysis is not supported by consistent theoretical studies. Our review is aimed, in part, at readers with a background in chemical physics and biophysics, and illustrates that despite a substantial body of experimental effort, there has not yet been any study that consistently established a connection between an enzyme's conformational dynamics and a significant increase in the catalytic contribution of the chemical step. We also make the point that the dynamical proposal is not a semantic issue but a well-defined scientific hypothesis with well-defined conclusions.
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Affiliation(s)
- Arieh Warshel
- Department of Chemistry, University of Southern California, SGM 418, 3620 McClintock Avenue, Los Angeles, California 90089, USA
| | - Ram Prasad Bora
- Department of Chemistry, University of Southern California, SGM 418, 3620 McClintock Avenue, Los Angeles, California 90089, USA
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20
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Campbell E, Kaltenbach M, Correy GJ, Carr PD, Porebski BT, Livingstone EK, Afriat-Jurnou L, Buckle AM, Weik M, Hollfelder F, Tokuriki N, Jackson CJ. The role of protein dynamics in the evolution of new enzyme function. Nat Chem Biol 2016; 12:944-950. [PMID: 27618189 DOI: 10.1038/nchembio.2175] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/17/2016] [Indexed: 11/09/2022]
Abstract
Enzymes must be ordered to allow the stabilization of transition states by their active sites, yet dynamic enough to adopt alternative conformations suited to other steps in their catalytic cycles. The biophysical principles that determine how specific protein dynamics evolve and how remote mutations affect catalytic activity are poorly understood. Here we examine a 'molecular fossil record' that was recently obtained during the laboratory evolution of a phosphotriesterase from Pseudomonas diminuta to an arylesterase. Analysis of the structures and dynamics of nine protein variants along this trajectory, and three rationally designed variants, reveals cycles of structural destabilization and repair, evolutionary pressure to 'freeze out' unproductive motions and sampling of distinct conformations with specific catalytic properties in bi-functional intermediates. This work establishes that changes to the conformational landscapes of proteins are an essential aspect of molecular evolution and that change in function can be achieved through enrichment of preexisting conformational sub-states.
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Affiliation(s)
- Eleanor Campbell
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Miriam Kaltenbach
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Galen J Correy
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Paul D Carr
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Benjamin T Porebski
- Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Emma K Livingstone
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Livnat Afriat-Jurnou
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Ashley M Buckle
- Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Martin Weik
- Institut de Biologie Structurale, University Grenoble Alpes, Commissariat à l'Energie Atomique and Centre National de la Recherche Scientifique, Grenoble, France
| | | | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, Australia
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21
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Luk LYP, Loveridge EJ, Allemann RK. Protein motions and dynamic effects in enzyme catalysis. Phys Chem Chem Phys 2016; 17:30817-27. [PMID: 25854702 DOI: 10.1039/c5cp00794a] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The role of protein motions in promoting the chemical step of enzyme catalysed reactions remains a subject of considerable debate. Here, a unified view of the role of protein dynamics in dihydrofolate reductase catalysis is described. Recently the role of such motions has been investigated by characterising the biophysical properties of isotopically substituted enzymes through a combination of experimental and computational analyses. Together with previous work, these results suggest that dynamic coupling to the chemical coordinate is detrimental to catalysis and may have been selected against during DHFR evolution. The full catalytic power of Nature's catalysts appears to depend on finely tuning protein motions in each step of the catalytic cycle.
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Affiliation(s)
- Louis Y P Luk
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
| | - E Joel Loveridge
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
| | - Rudolf K Allemann
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
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22
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Using natural sequences and modularity to design common and novel protein topologies. Curr Opin Struct Biol 2016; 38:26-36. [PMID: 27270240 DOI: 10.1016/j.sbi.2016.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/13/2016] [Accepted: 05/18/2016] [Indexed: 02/07/2023]
Abstract
Protein design is still a challenging undertaking, often requiring multiple attempts or iterations for success. Typically, the source of failure is unclear, and scoring metrics appear similar between successful and failed cases. Nevertheless, the use of sequence statistics, modularity and symmetry from natural proteins, combined with computational design both at the coarse-grained and atomistic levels is propelling a new wave of design efforts to success. Here we highlight recent examples of design, showing how the wealth of natural protein sequence and topology data may be leveraged to reduce the search space and increase the likelihood of achieving desired outcomes.
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23
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Pabis A, Duarte F, Kamerlin SCL. Promiscuity in the Enzymatic Catalysis of Phosphate and Sulfate Transfer. Biochemistry 2016; 55:3061-81. [PMID: 27187273 PMCID: PMC4899807 DOI: 10.1021/acs.biochem.6b00297] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
The
enzymes that facilitate phosphate and sulfate hydrolysis are
among the most proficient natural catalysts known to date. Interestingly,
a large number of these enzymes are promiscuous catalysts that exhibit
both phosphatase and sulfatase activities in the same active site
and, on top of that, have also been demonstrated to efficiently catalyze
the hydrolysis of other additional substrates with varying degrees
of efficiency. Understanding the factors that underlie such multifunctionality
is crucial both for understanding functional evolution in enzyme superfamilies
and for the development of artificial enzymes. In this Current Topic,
we have primarily focused on the structural and mechanistic basis
for catalytic promiscuity among enzymes that facilitate both phosphoryl
and sulfuryl transfer in the same active site, while comparing this
to how catalytic promiscuity manifests in other promiscuous phosphatases.
We have also drawn on the large number of experimental and computational
studies of selected model systems in the literature to explore the
different features driving the catalytic promiscuity of such enzymes.
Finally, on the basis of this comparative analysis, we probe the plausible
origins and determinants of catalytic promiscuity in enzymes that
catalyze phosphoryl and sulfuryl transfer.
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Affiliation(s)
- Anna Pabis
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University , BMC Box 596, S-751 24 Uppsala, Sweden
| | - Fernanda Duarte
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, U.K.,Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, U.K
| | - Shina C L Kamerlin
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University , BMC Box 596, S-751 24 Uppsala, Sweden
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24
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Gobeil SMC, Gagné D, Doucet N, Pelletier JN. 15N, 13C and 1H backbone resonance assignments of an artificially engineered TEM-1/PSE-4 class A β-lactamase chimera and its deconvoluted mutant. BIOMOLECULAR NMR ASSIGNMENTS 2016; 10:93-99. [PMID: 26386961 PMCID: PMC5419827 DOI: 10.1007/s12104-015-9645-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
The widespread use of β-lactam antibiotics has given rise to a dramatic increase in clinically-relevant β-lactamases. Understanding the structure/function relation in these variants is essential to better address the ever-growing incidence of antibiotic resistance. We previously reported the backbone resonance assignments of a chimeric protein constituted of segments of the class A β-lactamases TEM-1 and PSE-4 (Morin et al. in Biomol NMR Assign 4:127-130, 2010. doi: 10.1007/s12104-010-9227-8 ). That chimera, cTEM17m, held 17 amino acid substitutions relative to TEM-1 β-lactamase, resulting in a well-folded and fully functional protein with increased dynamics. Here we report the (1)H, (13)C and (15)N backbone resonance assignments of chimera cTEM-19m, which includes 19 substitutions and exhibits increased active-site perturbation, as well as one of its deconvoluted variants, as the first step in the analysis of their dynamic behaviours.
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Affiliation(s)
- Sophie M C Gobeil
- Department of Biochemistry, Université de Montréal, Montréal, QC, Canada
- PROTEO, The Québec Network for Research on Protein Function, Engineering and Applications, Québec, QC, Canada
| | - Donald Gagné
- PROTEO, The Québec Network for Research on Protein Function, Engineering and Applications, Québec, QC, Canada
- INRS-Institut Armand-Frappier, Université du Québec, Québec, QC, Canada
- GRASP, Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montréal, QC, Canada
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY, USA
| | - Nicolas Doucet
- PROTEO, The Québec Network for Research on Protein Function, Engineering and Applications, Québec, QC, Canada
- INRS-Institut Armand-Frappier, Université du Québec, Québec, QC, Canada
- GRASP, Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montréal, QC, Canada
| | - Joelle N Pelletier
- Department of Biochemistry, Université de Montréal, Montréal, QC, Canada.
- PROTEO, The Québec Network for Research on Protein Function, Engineering and Applications, Québec, QC, Canada.
- Department of Chemistry, Université de Montréal, Montréal, Canada.
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25
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Doyle CM, Rumfeldt JA, Broom HR, Sekhar A, Kay LE, Meiering EM. Concurrent Increases and Decreases in Local Stability and Conformational Heterogeneity in Cu, Zn Superoxide Dismutase Variants Revealed by Temperature-Dependence of Amide Chemical Shifts. Biochemistry 2016; 55:1346-61. [PMID: 26849066 DOI: 10.1021/acs.biochem.5b01133] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The chemical shifts of backbone amide protons in proteins are sensitive reporters of local structural stability and conformational heterogeneity, which can be determined from their readily measured linear and nonlinear temperature-dependences, respectively. Here we report analyses of amide proton temperature-dependences for native dimeric Cu, Zn superoxide dismutase (holo pWT SOD1) and structurally diverse mutant SOD1s associated with amyotrophic lateral sclerosis (ALS). Holo pWT SOD1 loses structure with temperature first at its periphery and, while having extremely high global stability, nevertheless exhibits extensive conformational heterogeneity, with ∼1 in 5 residues showing evidence for population of low energy alternative states. The holo G93A and E100G ALS mutants have moderately decreased global stability, whereas V148I is slightly stabilized. Comparison of the holo mutants as well as the marginally stable immature monomeric unmetalated and disulfide-reduced (apo(2SH)) pWT with holo pWT shows that changes in the local structural stability of individual amides vary greatly, with average changes corresponding to differences in global protein stability measured by differential scanning calorimetry. Mutants also exhibit altered conformational heterogeneity compared to pWT. Strikingly, substantial increases as well as decreases in local stability and conformational heterogeneity occur, in particular upon maturation and for G93A. Thus, the temperature-dependence of amide shifts for SOD1 variants is a rich source of information on the location and extent of perturbation of structure upon covalent changes and ligand binding. The implications for potential mechanisms of toxic misfolding of SOD1 in disease and for general aspects of protein energetics, including entropy-enthalpy compensation, are discussed.
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Affiliation(s)
| | | | | | | | - Lewis E Kay
- Program in Molecular Structure and Function, Hospital for Sick Children , Toronto, Canada
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26
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Abstract
Although protein dynamics are accepted as being essential for enzyme function, their effects are not fully understood. In this issue of Chemistry and Biology, Gobeil and coworkers describe how engineered changes in the millisecond motions of a mutant TEM-1 β-lactamase do not significantly affect substrate turnover. This mutational robustness has implications for protein engineering and design strategies.
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Affiliation(s)
- Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
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27
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Dellus-Gur E, Elias M, Caselli E, Prati F, Salverda MLM, de Visser JAGM, Fraser JS, Tawfik DS. Negative Epistasis and Evolvability in TEM-1 β-Lactamase--The Thin Line between an Enzyme's Conformational Freedom and Disorder. J Mol Biol 2015; 427:2396-409. [PMID: 26004540 DOI: 10.1016/j.jmb.2015.05.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/08/2015] [Accepted: 05/12/2015] [Indexed: 12/28/2022]
Abstract
Epistasis is a key factor in evolution since it determines which combinations of mutations provide adaptive solutions and which mutational pathways toward these solutions are accessible by natural selection. There is growing evidence for the pervasiveness of sign epistasis--a complete reversion of mutational effects, particularly in protein evolution--yet its molecular basis remains poorly understood. We describe the structural basis of sign epistasis between G238S and R164S, two adaptive mutations in TEM-1 β-lactamase--an enzyme that endows antibiotics resistance. Separated by 10 Å, these mutations initiate two separate trajectories toward increased hydrolysis rates and resistance toward second and third-generation cephalosporins antibiotics. Both mutations allow the enzyme's active site to adopt alternative conformations and accommodate the new antibiotics. By solving the corresponding set of crystal structures, we found that R164S causes local disorder whereas G238S induces discrete conformations. When combined, the mutations in 238 and 164 induce local disorder whereby nonproductive conformations that perturb the enzyme's catalytic preorganization dominate. Specifically, Asn170 that coordinates the deacylating water molecule is misaligned, in both the free form and the inhibitor-bound double mutant. This local disorder is not restored by stabilizing global suppressor mutations and thus leads to an evolutionary cul-de-sac. Conformational dynamism therefore underlines the reshaping potential of protein's structures and functions but also limits protein evolvability because of the fragility of the interactions networks that maintain protein structures.
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Affiliation(s)
- Eynat Dellus-Gur
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mikael Elias
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Emilia Caselli
- Department of Chemistry, University of Modena, Modena 41100, Italy
| | - Fabio Prati
- Department of Chemistry, University of Modena, Modena 41100, Italy
| | - Merijn L M Salverda
- Institute for Translational Vaccinology (Intravacc), Bilthoven 3720 AL, The Netherlands
| | - J Arjan G M de Visser
- Laboratory of Genetics, Department of Plant Sciences, Wageningen University, Wageningen 6700 AH, The Netherlands
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA.
| | - Dan S Tawfik
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
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28
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Bora RP, Mills MJL, Frushicheva MP, Warshel A. On the challenge of exploring the evolutionary trajectory from phosphotriesterase to arylesterase using computer simulations. J Phys Chem B 2015; 119:3434-45. [PMID: 25620270 PMCID: PMC11343073 DOI: 10.1021/jp5124025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The ability to design effective enzymes presents a fundamental challenge in biotechnology and also in biochemistry. Unfortunately, most of the progress on this field has been accomplished by bringing the reactants to a reasonable orientation relative to each other, rather than by rational optimization of the polar preorganization of the environment, which is the most important catalytic factor. True computer based enzyme design would require the ability to evaluate the catalytic power of designed active sites. This work considers the evolution from a phosphotriesterase (with the paraoxon substrate) to arylesterase (with the 2-naphthylhexanoate (2NH) substrate) catalysis. Both the original and the evolved enzymes involve two zinc ions and their ligands, making it hard to obtain a reliable quantum mechanical description and then to obtain an effective free energy sampling. Furthermore, the options for the reaction path are quite complicated. To progress in this direction we started with DFT calculations of the energetics of different mechanistic options of cluster models and then used the results to calibrate empirical valence bond (EVB) models and to generate properly sampled free energy surfaces for different mechanisms in the enzyme. Interestingly, it is found that the catalytic effect depends on the Zn-Zn distance making the mechanistic analysis somewhat complicated. Comparing the activation barriers of paraoxon and the 2NH ester at the beginning and end of the evolutionary path reproduced the observed evolutionary trend. However, although our findings provide an advance in exploring the nature of promiscuous enzymes, they also indicate that modeling the reaction mechanism in the case of enzymes with a binuclear zinc center is far from trivial and presents a challenge for computer-aided enzyme design.
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Affiliation(s)
- Ram Prasad Bora
- Department of Chemistry, University of Southern California, 3620 McClintock Avenue, Los Angeles, California 90089, United States
| | - Matthew J. L. Mills
- Deconstruction Division, Joint BioEnergy Institute, Emeryville, California, United States & Biomass Science and Conversion Technology Department, Sandia National Laboratories, Livermore, California 94550, United States
| | - Maria P. Frushicheva
- Department of Chemical Engineering, Massachusetts Institute of Technology, 25 Ames Street, Cambridge, Massachusetts 02142, United States
| | - Arieh Warshel
- Department of Chemistry, University of Southern California, 3620 McClintock Avenue, Los Angeles, California 90089, United States
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