1
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Karamitros CS, Murray K, Kumada Y, Johnson KA, D'Arcy S, Georgiou G. Mechanistic conformational and substrate selectivity profiles emerging in the evolution of enzymes via parallel trajectories. Nat Commun 2024; 15:7068. [PMID: 39152129 PMCID: PMC11329768 DOI: 10.1038/s41467-024-51133-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: 07/08/2023] [Accepted: 07/30/2024] [Indexed: 08/19/2024] Open
Abstract
Laboratory evolution studies have demonstrated that parallel evolutionary trajectories can lead to genetically distinct enzymes with high activity towards a non-preferred substrate. However, it is unknown whether such enzymes have convergent conformational dynamics and mechanistic features. To address this question, we use as a model the wild-type Homo sapiens kynureninase (HsKYNase), which is of great interest for cancer immunotherapy. Earlier, we isolated HsKYNase_66 through an unusual evolutionary trajectory, having a 410-fold increase in the kcat/KM for kynurenine (KYN) and reverse substrate selectivity relative to HsKYNase. Here, by following a different evolutionary trajectory we generate a genetically distinct variant, HsKYNase_93D9, that exhibits KYN catalytic activity comparable to that of HsKYNase_66, but instead it is a "generalist" that accepts 3'-hydroxykynurenine (OH-KYN) with the same proficiency. Pre-steady-state kinetic analysis reveals that while the evolution of HsKYNase_66 is accompanied by a change in the rate-determining step of the reactions, HsKYNase_93D9 retains the same catalytic mechanism as HsKYNase. HDX-MS shows that the conformational dynamics of the two enzymes are markedly different and distinct from ortholog prokaryotic enzymes with high KYN activity. Our work provides a mechanistic framework for understanding the relationship between evolutionary mechanisms and phenotypic traits of evolved generalist and specialist enzyme species.
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Affiliation(s)
- Christos S Karamitros
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, TX, USA
- Research and Clinical Development, Nestlé Health Science, Lausanne, 1000, Switzerland
| | - Kyle Murray
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
- Trajan Scientific America's, Inc. Boston, Massachusetts, MA, USA
| | - Yoichi Kumada
- Department of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Kyoto, Japan
| | - Kenneth A Johnson
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, TX, USA
| | - Sheena D'Arcy
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - George Georgiou
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, TX, USA.
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, TX, USA.
- Department of Biomedical Engineering, University of Texas at Austin (UT Austin), Austin, TX, USA.
- Institute for Cellular and Molecular Biology, The University of Texas at Austin (UT Austin), Austin, TX, USA.
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2
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Shanbhag AP, Bhowmik P. Cancer to Cataracts: The Mechanistic Impact of Aldo-Keto Reductases in Chronic Diseases. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2024; 97:179-204. [PMID: 38947111 PMCID: PMC11202113 DOI: 10.59249/vtbv6559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Aldo-keto reductases (AKRs) are a superfamily of promiscuous enzymes that have been chiseled by evolution to act as catalysts for numerous regulatory pathways in humans. However, they have not lost their promiscuity in the process, essentially making them a double-edged sword. The superfamily is involved in multiple metabolic pathways and are linked to chronic diseases such as cataracts, diabetes, and various cancers. Unlike other detoxifying enzymes such as cytochrome P450s (CYP450s), short-chain dehydrogenases (SDRs), and medium-chain dehydrogenases (MDRs), that participate in essential pathways, AKRs are more widely distributed and have members with interchangeable functions. Moreover, their promiscuity is ubiquitous across all species and participates in the resistance of pathogenic microbes. Moreover, the introduction of synthetic substrates, such as synthetic molecules and processed foods, results in unwanted "toxification" due to enzyme promiscuity, leading to chronic diseases.
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Affiliation(s)
- Anirudh P. Shanbhag
- Bugworks Research India Pvt. Ltd., Bengaluru,
Karnataka, India
- Novartis Healthcare Pvt. Ltd., Hyderabad, Telangana,
India
| | - Purnendu Bhowmik
- Bugworks Research India Pvt. Ltd., Bengaluru,
Karnataka, India
- Centre for Cellular and Molecular Platforms (C-CAMP),
National Centre for Biological Sciences (NCBS), Bengaluru, Karnataka,
India
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3
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Hashemi S, Laitinen R, Nikoloski Z. Models and molecular mechanisms for trade-offs in the context of metabolism. Mol Ecol 2024; 33:e16879. [PMID: 36773330 DOI: 10.1111/mec.16879] [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: 08/10/2022] [Revised: 01/19/2023] [Accepted: 02/07/2023] [Indexed: 02/13/2023]
Abstract
Accumulating evidence for trade-offs involving metabolic traits has demonstrated their importance in the evolution of organisms. Metabolic models with different levels of complexity have already been considered when investigating mechanisms that explain various metabolic trade-offs. Here we provide a systematic review of modelling approaches that have been used to study and explain trade-offs between: (i) the kinetic properties of individual enzymes, (ii) rates of metabolic reactions, (iii) the rate and yield of metabolic pathways and networks, (iv) different metabolic objectives in single organisms and in metabolic communities, and (v) metabolic concentrations. In providing insights into the mechanisms underlying these five types of metabolic trade-offs obtained from constraint-based metabolic modelling, we emphasize the relationship of metabolic trade-offs to the classical black box Y-model that provides a conceptual explanation for resource acquisition-allocation trade-offs. In addition, we identify several pressing concerns and offer a perspective for future research in the identification and manipulation of metabolic trade-offs by relying on the toolbox provided by constraint-based metabolic modelling for single organisms and microbial communities.
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Affiliation(s)
- Seirana Hashemi
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Systems Biology and Mathematical Modelling, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - Roosa Laitinen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Zoran Nikoloski
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Systems Biology and Mathematical Modelling, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
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4
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Kozome D, Sljoka A, Laurino P. Remote loop evolution reveals a complex biological function for chitinase enzymes beyond the active site. Nat Commun 2024; 15:3227. [PMID: 38622119 PMCID: PMC11018821 DOI: 10.1038/s41467-024-47588-8] [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: 01/29/2024] [Accepted: 04/08/2024] [Indexed: 04/17/2024] Open
Abstract
Loops are small secondary structural elements that play a crucial role in the emergence of new enzyme functions. However, the evolutionary molecular mechanisms how proteins acquire these loop elements and obtain new function is poorly understood. To address this question, we study glycoside hydrolase family 19 (GH19) chitinase-an essential enzyme family for pathogen degradation in plants. By revealing the evolutionary history and loops appearance of GH19 chitinase, we discover that one loop which is remote from the catalytic site, is necessary to acquire the new antifungal activity. We demonstrate that this remote loop directly accesses the fungal cell wall, and surprisingly, it needs to adopt a defined structure supported by long-range intramolecular interactions to perform its function. Our findings prove that nature applies this strategy at the molecular level to achieve a complex biological function while maintaining the original activity in the catalytic pocket, suggesting an alternative way to design new enzyme function.
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Affiliation(s)
- Dan Kozome
- Protein Engineering and Evolution Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, 904-0495, Japan
| | - Adnan Sljoka
- Center for Advanced Intelligence Project, RIKEN, Tokyo, 103-0027, Japan
- Department of Chemistry, York University, Toronto, ON, M3J 1P3, Canada
| | - Paola Laurino
- Protein Engineering and Evolution Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, 904-0495, Japan.
- Institute for Protein Research, Osaka University, Suita, Japan.
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5
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Schmutzer M, Dasmeh P, Wagner A. Frustration can Limit the Adaptation of Promiscuous Enzymes Through Gene Duplication and Specialisation. J Mol Evol 2024; 92:104-120. [PMID: 38470504 PMCID: PMC10978624 DOI: 10.1007/s00239-024-10161-4] [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: 10/07/2023] [Accepted: 02/16/2024] [Indexed: 03/14/2024]
Abstract
Virtually all enzymes catalyse more than one reaction, a phenomenon known as enzyme promiscuity. It is unclear whether promiscuous enzymes are more often generalists that catalyse multiple reactions at similar rates or specialists that catalyse one reaction much more efficiently than other reactions. In addition, the factors that shape whether an enzyme evolves to be a generalist or a specialist are poorly understood. To address these questions, we follow a three-pronged approach. First, we examine the distribution of promiscuity in empirical enzymes reported in the BRENDA database. We find that the promiscuity distribution of empirical enzymes is bimodal. In other words, a large fraction of promiscuous enzymes are either generalists or specialists, with few intermediates. Second, we demonstrate that enzyme biophysics is not sufficient to explain this bimodal distribution. Third, we devise a constraint-based model of promiscuous enzymes undergoing duplication and facing selection pressures favouring subfunctionalization. The model posits the existence of constraints between the catalytic efficiencies of an enzyme for different reactions and is inspired by empirical case studies. The promiscuity distribution predicted by our constraint-based model is consistent with the empirical bimodal distribution. Our results suggest that subfunctionalization is possible and beneficial only in certain enzymes. Furthermore, the model predicts that conflicting constraints and selection pressures can cause promiscuous enzymes to enter a 'frustrated' state, in which competing interactions limit the specialisation of enzymes. We find that frustration can be both a driver and an inhibitor of enzyme evolution by duplication and subfunctionalization. In addition, our model predicts that frustration becomes more likely as enzymes catalyse more reactions, implying that natural selection may prefer catalytically simple enzymes. In sum, our results suggest that frustration may play an important role in enzyme evolution.
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Affiliation(s)
- Michael Schmutzer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Pouria Dasmeh
- Center for Human Genetics, Philipps University of Marburg, Marburg, Germany
| | - Andreas Wagner
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
- Santa Fe Institute, Santa Fe, NM, USA.
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6
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Matsumura I, Patrick WM. Dan Tawfik's Lessons for Protein Engineers about Enzymes Adapting to New Substrates. Biochemistry 2022; 62:158-162. [PMID: 35820168 PMCID: PMC9851151 DOI: 10.1021/acs.biochem.2c00230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Natural evolution has been creating new complex systems for billions of years. The process is spontaneous and requires neither intelligence nor moral purpose but is nevertheless difficult to understand. The late Dan Tawfik spent years studying enzymes as they adapted to recognize new substrates. Much of his work focused on gaining fundamental insights, so the practical utility of his experiments may not be obvious even to accomplished protein engineers. Here we focus on two questions fundamental to any directed evolution experiment. Which proteins are the best starting points for such experiments? Which trait(s) of the chosen parental protein should be evolved to achieve the desired outcome? We summarize Tawfik's contributions to our understanding of these problems, to honor his memory and encourage those unfamiliar with his ideas to read his publications.
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Affiliation(s)
- Ichiro Matsumura
- O.
Wayne Rollins Research Center, 1510 Clifton Road NE, Room 4001, Atlanta, Georgia 30322, United States,E-mail:
| | - Wayne M. Patrick
- Centre
for Biodiscovery, School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand,E-mail:
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7
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Heyne M, Shirian J, Cohen I, Peleg Y, Radisky ES, Papo N, Shifman JM. Climbing Up and Down Binding Landscapes through Deep Mutational Scanning of Three Homologous Protein-Protein Complexes. J Am Chem Soc 2021; 143:17261-17275. [PMID: 34609866 PMCID: PMC8532158 DOI: 10.1021/jacs.1c08707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 12/18/2022]
Abstract
Protein-protein interactions (PPIs) have evolved to display binding affinities that can support their function. As such, cognate and noncognate PPIs could be highly similar structurally but exhibit huge differences in binding affinities. To understand this phenomenon, we study three homologous protease-inhibitor PPIs that span 9 orders of magnitude in binding affinity. Using state-of-the-art methodology that combines protein randomization, affinity sorting, deep sequencing, and data normalization, we report quantitative binding landscapes consisting of ΔΔGbind values for the three PPIs, gleaned from tens of thousands of single and double mutations. We show that binding landscapes of the three complexes are strikingly different and depend on the PPI evolutionary optimality. We observe different patterns of couplings between mutations for the three PPIs with negative and positive epistasis appearing most frequently at hot-spot and cold-spot positions, respectively. The evolutionary trends observed here are likely to be universal to other biological complexes in the cell.
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Affiliation(s)
- Michael Heyne
- Department
of Biological Chemistry, The Alexander Silberman Institute of Life
Sciences, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Avram
and Stella Goldstein-Goren Department of Biotechnology Engineering
and the National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Jason Shirian
- Department
of Biological Chemistry, The Alexander Silberman Institute of Life
Sciences, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Itay Cohen
- Avram
and Stella Goldstein-Goren Department of Biotechnology Engineering
and the National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Yoav Peleg
- Life
Sciences Core Facilities (LSCF) Structural Proteomics Unit (SPU), Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Evette S. Radisky
- Department
of Cancer Biology, Mayo Clinic Comprehensive
Cancer Center, Jacksonville, Florida 32224, United States
| | - Niv Papo
- Avram
and Stella Goldstein-Goren Department of Biotechnology Engineering
and the National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Julia M. Shifman
- Department
of Biological Chemistry, The Alexander Silberman Institute of Life
Sciences, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
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8
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Alex Wong CF, van Vliet L, Bhujbal SV, Guo C, Sletmoen M, Stokke BT, Hollfelder F, Lale R. A Titratable Cell Lysis-on-Demand System for Droplet-Compartmentalized Ultrahigh-Throughput Screening in Functional Metagenomics and Directed Evolution. ACS Synth Biol 2021; 10:1882-1894. [PMID: 34260196 PMCID: PMC8383311 DOI: 10.1021/acssynbio.1c00084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Water-in-oil emulsion
droplets are an attractive format for ultrahigh-throughput
screening in functional metagenomics and directed evolution applications
that allow libraries with more than 107 members to be characterized
in a day. Single library members are compartmentalized in droplets
that are generated in microfluidic devices and tested for the presence
of target biocatalysts. The target proteins can be produced intracellularly,
for example, in bacterial hosts in-droplet cell lysis is therefore
necessary to allow the enzymes to encounter the substrate to initiate
an activity assay. Here, we present a titratable lysis-on-demand (LoD)
system enabling the control of the cell lysis rate in Escherichia
coli. We demonstrate that the rate of cell lysis can be controlled
by adjusting the externally added inducer concentration. This LoD
system is evaluated both at the population level (by optical density
measurements) and at the single-cell level (on single-cell arrays
and in alginate microbeads). Additionally, we validate the LoD system
by droplet screening of a phosphotriesterase expressed from E. coli, with cell lysis triggered by inducer concentrations
in the μM range. The LoD system yields sufficient release of
the intracellularly produced enzymes to bring about a detectable quantity
of product (measured by fluorescence in flow cytometry of double emulsions),
while leaving viable cells for the downstream recovery of the genetic
material.
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Affiliation(s)
- Che Fai Alex Wong
- Department of Biotechnology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Liisa van Vliet
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, United Kingdom
| | - Swapnil Vilas Bhujbal
- Department of Biotechnology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Chengzhi Guo
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, United Kingdom
| | - Marit Sletmoen
- Department of Biotechnology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Bjørn Torger Stokke
- Department of Physics, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, United Kingdom
| | - Rahmi Lale
- Department of Biotechnology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
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9
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Hall KR, Robins KJ, Williams EM, Rich MH, Calcott MJ, Copp JN, Little RF, Schwörer R, Evans GB, Patrick WM, Ackerley DF. Intracellular complexities of acquiring a new enzymatic function revealed by mass-randomisation of active-site residues. eLife 2020; 9:59081. [PMID: 33185191 PMCID: PMC7738182 DOI: 10.7554/elife.59081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/12/2020] [Indexed: 11/17/2022] Open
Abstract
Selection for a promiscuous enzyme activity provides substantial opportunity for competition between endogenous and newly-encountered substrates to influence the evolutionary trajectory, an aspect that is often overlooked in laboratory directed evolution studies. We selected the Escherichia coli nitro/quinone reductase NfsA for chloramphenicol detoxification by simultaneously randomising eight active-site residues and interrogating ~250,000,000 reconfigured variants. Analysis of every possible intermediate of the two best chloramphenicol reductases revealed complex epistatic interactions. In both cases, improved chloramphenicol detoxification was only observed after an R225 substitution that largely eliminated activity with endogenous quinones. Error-prone PCR mutagenesis reinforced the importance of R225 substitutions, found in 100% of selected variants. This strong activity trade-off demonstrates that endogenous cellular metabolites hold considerable potential to shape evolutionary outcomes. Unselected prodrug-converting activities were mostly unaffected, emphasising the importance of negative selection to effect enzyme specialisation, and offering an application for the evolved genes as dual-purpose selectable/counter-selectable markers. In the cell, most tasks are performed by big molecules called proteins, which behave like molecular machines. Although proteins are often described as having one job each, this is not always true, and many proteins can perform different roles. Enzymes are a type of protein that facilitate chemical reactions. They are often specialised to one reaction, but they can also accelerate other side-reactions. During evolution, these side-reactions can become more useful and, as a result, the role of the enzyme may change over time. The main role of the enzyme called NfsA in Escherichia coli bacteria is thought to be to convert molecules called quinones into hydroquinones, which can protect the cell from toxic molecules produced in oxidation reactions. As a side-reaction, NfsA has the potential to protect bacteria from an antibiotic called chloramphenicol, but it generally does this with such low efficacy that the effects are negligible. Producing hydroquinones is helpful to the cell in some situations, but if bacteria are regularly exposed to chloramphenicol, NfsA’s role aiding antibiotic resistance could become more important. Over time, the enzyme could evolve to become better at neutralising chloramphenicol. Therefore, NfsA provides an opportunity to study the evolution of proteins and how bacteria adapt to antibiotics. To see how evolution might affect the activity of NfsA, Hall et al. generated 250 million E. coli with either random or targeted changes to the gene that codes for the NfsA enzyme. The resulting variants of NfsA that were most effective against chloramphenicol all had a change that eliminated the enzyme’s ability to convert quinones. This result demonstrates a key trade-off between roles for NfsA, where one must be lost for the other to improve. These results demonstrate the interplay between a protein’s different roles and provide insight into bacterial drug resistance. Additionally, the experiments showed that the bacteria with improved resistance to chloramphenicol also became more sensitive to another antibiotic, metronidazole. These findings could inform the fight against drug-resistant bacterial infections and may also be helpful in guiding the design of proteins with different roles.
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Affiliation(s)
- Kelsi R Hall
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Katherine J Robins
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Elsie M Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Michelle H Rich
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Mark J Calcott
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Janine N Copp
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Rory F Little
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Ralf Schwörer
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand.,Ferrier Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Gary B Evans
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand.,Ferrier Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Wayne M Patrick
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
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10
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Lundin E, Näsvall J, Andersson DI. Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence. Front Microbiol 2020; 11:588235. [PMID: 33154742 PMCID: PMC7591586 DOI: 10.3389/fmicb.2020.588235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
When a new activity evolves by changes in a pre-existing enzyme this is likely to reduce the original activity, generating a functional trade-off. The properties of this trade-off will affect the continued evolution of both functions. If the trade-off is strong, gene duplication and subsequent divergence would be favored whereas if the trade-off is weak a bi-functional enzyme could evolve that performs both functions. We previously showed that when a bi-functional HisA enzyme was evolved under selection for both HisA and TrpF functions, evolution mainly proceeded via duplication-divergence and specialization, implying that the trade-off is strong between these two functions. Here, we examined this hypothesis by identifying the mutational pathways (i.e., the mutational landscape) in the Salmonella enterica HisA enzyme that conferred a TrpF-like activity, and examining the trade-offs between the original and new activity. For the HisA enzyme there are many different paths toward the new TrpF function, each with its own unique trade-off. A total of 16 single mutations resulted in HisA enzyme variants that acquired TrpF activity and only three of them maintained HisA activity. Twelve mutants were evolved further toward increased TrpF activity and during evolution toward improved TrpF activity the original HisA activity was completely lost in all lineages. We propose that, aside from various relevant ecological factors, two main genetic factors influence whether evolution of a new function proceeds via duplication – divergence (specialization) or by evolution of a generalist: (i) the relative mutation supply of the two pathways and (ii) the shape of the trade-off curve between the native and new function.
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Affiliation(s)
- Erik Lundin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Joakim Näsvall
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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11
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Noda-Garcia L, Tawfik DS. Enzyme evolution in natural products biosynthesis: target- or diversity-oriented? Curr Opin Chem Biol 2020; 59:147-154. [PMID: 32771972 DOI: 10.1016/j.cbpa.2020.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022]
Abstract
Natural product biosynthesis (NPB) is the Panda's Thumb of evolutionary biochemistry. Arm races between organisms, and ever-changing environments, result in relentless innovation. This review focusses on enzyme evolution in NPB. First, we review cases of de novo emergence, whereby a completely new enzymatic activity arose in a ligand-binding protein, or a new enzyme emerged including a completely new scaffold. Second, we briefly review the current models for enzyme evolution, and how they explain the inherent promiscuity of NPB enzymes and their tendency to produce multiple related products. We thus suggest that NPB enzymes a priori evolved to generate a specific product; they are, however, trapped in a multifunctional, generalist evolutionary state and thereby produce a diversity of products.
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Affiliation(s)
- Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Dan S Tawfik
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100, Israel.
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12
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Emond S, Petek M, Kay EJ, Heames B, Devenish SRA, Tokuriki N, Hollfelder F. Accessing unexplored regions of sequence space in directed enzyme evolution via insertion/deletion mutagenesis. Nat Commun 2020; 11:3469. [PMID: 32651386 PMCID: PMC7351745 DOI: 10.1038/s41467-020-17061-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 06/01/2020] [Indexed: 11/22/2022] Open
Abstract
Insertions and deletions (InDels) are frequently observed in natural protein evolution, yet their potential remains untapped in laboratory evolution. Here we introduce a transposon-based mutagenesis approach (TRIAD) to generate libraries of random variants with short in-frame InDels, and screen TRIAD libraries to evolve a promiscuous arylesterase activity in a phosphotriesterase. The evolution exhibits features that differ from previous point mutagenesis campaigns: while the average activity of TRIAD variants is more compromised, a larger proportion has successfully adapted for the activity. Different functional profiles emerge: (i) both strong and weak trade-off between activities are observed; (ii) trade-off is more severe (20- to 35-fold increased kcat/KM in arylesterase with 60-400-fold decreases in phosphotriesterase activity) and (iii) improvements are present in kcat rather than just in KM, suggesting adaptive solutions. These distinct features make TRIAD an alternative to widely used point mutagenesis, accessing functional innovations and traversing unexplored fitness landscape regions.
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Affiliation(s)
- Stephane Emond
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK.
- Evonetix Ltd, Coldhams Business Park, Norman Way, Cambridge, CB1 3LH, UK.
| | - Maya Petek
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - Emily J Kay
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
- Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK
| | - Brennen Heames
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
- Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität, Hüfferstrasse 1, 48149, Münster, Germany
| | - Sean R A Devenish
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
- Fluidic Analytics, The Paddocks Business Centre, Cherry Hinton Road, Cambridge, CB1 8DH, UK
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK.
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13
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Khan MS, Gargiulo S, Soumillion P. Promiscuous activity of 3-isopropylmalate dehydrogenase produced at physiological level affords Escherichia coli growth on d-malate. FEBS Lett 2020; 594:2421-2430. [PMID: 32412093 DOI: 10.1002/1873-3468.13814] [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: 02/05/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 11/08/2022]
Abstract
Promiscuous activities of enzymes may serve as starting points for the evolution of new functions. However, most experimental examples of promiscuity affording an observable phenotype necessitate the artificial overexpression of the target enzyme. Here, we show that 3-isopropylmalate dehydrogenase (IPMDH), an enzyme involved in leucine biosynthesis, has a secondary activity on d-malate, which is sufficient for d-malate assimilation under physiological conditions where the enzyme is upregulated. In vitro, the turnover constant (kcat ) of IPMDH for d-malate is about 30-fold lower than the kcat for 3-isopropylmalate, yet sufficiently high to support the growth on d-malate. From an evolutionary perspective, our results highlight the possibility of phenotype emergence triggered by arbitrary changes in environmental conditions and prior to any mutational event.
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Affiliation(s)
- Mohammad Shahneawz Khan
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium.,University of Dhaka, Bangladesh
| | - Serena Gargiulo
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Patrice Soumillion
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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14
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Structural and Functional Characterization of New SsoPox Variant Points to the Dimer Interface as a Driver for the Increase in Promiscuous Paraoxonase Activity. Int J Mol Sci 2020; 21:ijms21051683. [PMID: 32121487 PMCID: PMC7084321 DOI: 10.3390/ijms21051683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/02/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022] Open
Abstract
Increasing attention is more and more directed toward the thermostable Phosphotriesterase-Like-Lactonase (PLL) family of enzymes, for the efficient and reliable decontamination of toxic nerve agents. In the present study, the DNA Staggered Extension Process (StEP) technique was utilized to obtain new variants of PLL enzymes. Divergent homologous genes encoding PLL enzymes were utilized as templates for gene recombination and yielded a new variant of SsoPox from Saccharolobus solfataricus. The new mutant, V82L/C258L/I261F/W263A (4Mut) exhibited catalytic efficiency of 1.6 × 105 M−1 s−1 against paraoxon hydrolysis at 70°C, which is more than 3.5-fold and 42-fold improved in comparison with C258L/I261F/W263A (3Mut) and wild type SsoPox, respectively. 4Mut was also tested with chemical warfare nerve agents including tabun, sarin, soman, cyclosarin and VX. In particular, 4Mut showed about 10-fold enhancement in the hydrolysis of tabun and soman with respect to 3Mut. The crystal structure of 4Mut has been solved at the resolution of 2.8 Å. We propose that, reorganization of dimer conformation that led to increased central groove volume and dimer flexibility could be the major determinant for the improvement in hydrolytic activity in the 4Mut.
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15
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Glasner ME, Truong DP, Morse BC. How enzyme promiscuity and horizontal gene transfer contribute to metabolic innovation. FEBS J 2020; 287:1323-1342. [PMID: 31858709 DOI: 10.1111/febs.15185] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/22/2019] [Accepted: 12/18/2019] [Indexed: 01/12/2023]
Abstract
Promiscuity is the coincidental ability of an enzyme to catalyze its native reaction and additional reactions that are not biological functions in the same active site. Promiscuity plays a central role in enzyme evolution and is thus a useful property for protein and metabolic engineering. This review examines enzyme evolution holistically, beginning with evaluating biochemical support for four enzyme evolution models. As expected, there is strong biochemical support for the subfunctionalization and innovation-amplification-divergence models, in which promiscuity is a central feature. In many cases, however, enzyme evolution is more complex than the models indicate, suggesting much is yet to be learned about selective pressures on enzyme function. A complete understanding of enzyme evolution must also explain the ability of metabolic networks to integrate new enzyme activities. Hidden within metabolic networks are underground metabolic pathways constructed from promiscuous activities. We discuss efforts to determine the diversity and pervasiveness of underground metabolism. Remarkably, several studies have discovered that some metabolic defects can be repaired via multiple underground routes. In prokaryotes, metabolic innovation is driven by connecting enzymes acquired by horizontal gene transfer (HGT) into the metabolic network. Thus, we end the review by discussing how the combination of promiscuity and HGT contribute to evolution of metabolism in prokaryotes. Future studies investigating the contribution of promiscuity to enzyme and metabolic evolution will need to integrate deeper probes into the influence of evolution on protein biophysics, enzymology, and metabolism with more complex and realistic evolutionary models. ENZYMES: lactate dehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.37), OSBS (EC 4.2.1.113), HisA (EC 5.3.1.16), TrpF, PriA (EC 5.3.1.24), R-mandelonitrile lyase (EC 4.1.2.10), Maleylacetate reductase (EC 1.3.1.32).
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Affiliation(s)
- Margaret E Glasner
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Dat P Truong
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Benjamin C Morse
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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16
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Werner N, Ramirez-Sarmiento CA, Agosin E. Protein engineering of carotenoid cleavage dioxygenases to optimize β-ionone biosynthesis in yeast cell factories. Food Chem 2019; 299:125089. [PMID: 31319343 DOI: 10.1016/j.foodchem.2019.125089] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
Abstract
Synthesis of β-ionone in recombinant Saccharomyces cerevisiae is limited by the efficiency of Carotenoid Cleavage Dioxygenases (CCD), membrane-tethered enzymes catalyzing the last step in the pathway. We performed in silico design and membrane affinity analysis, focused on single-point mutations of PhCCD1 to improve membrane anchoring. The resulting constructs were tested in a β-carotene hyper-producing strain by comparing colony pigmentation against colonies transformed with native PhCCD1 and further analyzed by β-ionone quantification via RP-HPLC. Two single-point mutants increased β-ionone yields almost 3-fold when compared to native PhCCD1. We also aimed to improve substrate accessibility of PhCCD1 through the amino-terminal addition of membrane destination peptides directed towards the endoplasmic reticulum or plasma membrane. Yeast strains expressing peptide-PhCCD1 constructs showed β-ionone yields up to 4-fold higher than the strain carrying the native enzyme. Our results demonstrate that protein engineering of CCDs significantly increases the yield of β-ionone synthesized by metabolically engineered yeast.
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Affiliation(s)
- Nicole Werner
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
| | - César A Ramirez-Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
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17
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Zhong Z, Liu CC. Probing pathways of adaptation with continuous evolution. CURRENT OPINION IN SYSTEMS BIOLOGY 2019; 14:18-24. [PMID: 31608311 PMCID: PMC6788780 DOI: 10.1016/j.coisb.2019.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ziwei Zhong
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - Chang C. Liu
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697, USA
- Lead Contact
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18
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Abstract
Infections due to carbapenemase-producing Gram-negative pathogens are associated with limited treatment options and consequently lead to increased mortality and morbidity. In response, combinations of existing β-lactams and novel β-lactamase inhibitors, such as ceftazidime-avibactam (CAZ-AVI), have been developed as alternative treatment options. To understand the development of resistance and evolutionary trajectories under CAZ-AVI exposure, we studied the effects of ceftazidime (CAZ) and CAZ-AVI on the carbapenemase OXA-48 and the epidemic OXA-48 plasmid in Escherichia coli Exposure of CAZ and CAZ-AVI resulted in single (P68A) and double (P68A,Y211S) amino acid substitutions in OXA-48, respectively. The antimicrobial susceptibility data and enzyme kinetics showed that the P68A substitution was responsible for an increased activity toward CAZ, whereas P68A,Y211S led to a decrease in the inhibitory activity of AVI. X-ray crystallography and molecular modeling of the mutants demonstrated increased flexibility within the active site, which could explain the elevated CAZ hydrolysis and reduced inhibitory activity of AVI. Interestingly, these substitutions resulted in collateral effects compromising the activity of OXA-48 toward carbapenems and penicillins. Moreover, exposure to CAZ-AVI selected for mutations within the OXA-48-encoding plasmid that severely reduced fitness in the absence of antimicrobial selection. These evolutionary trade-offs may contribute to limit the evolution of OXA-48-mediated CAZ and CAZ-AVI resistance, as well as potentially resensitize isolates toward other therapeutic alternatives.IMPORTANCE The recent introduction of novel β-lactam/β-lactamase inhibitor combinations like ceftazidime-avibactam has increased our ability to treat infections caused by multidrug-resistant Gram-negative bacteria, including carbapenemase-producing Enterobacterales However, the increasing number of cases of reported resistance to ceftazidime-avibactam is a concern. OXA-48 is a carbapenemase that has no significant effect on ceftazidime, but is inhibited by avibactam. Since isolates with OXA-48 frequently harbor extended-spectrum β-lactamases that are inhibited by avibactam, it is likely that ceftazidime-avibactam will be used to treat infections caused by OXA-48-producing Enterobacterales. Our data show that exposure to ceftazidime-avibactam can lead to changes in OXA-48, resulting in increased ability to hydrolyze ceftazidime and withstand the inhibitory effect of avibactam. Thus, resistance toward ceftazidime-avibactam among OXA-48-producing Enterobacterales should be monitored. Interestingly, the compromising effect of the amino acid substitutions in OXA-48 on other β-lactams and the effect of ceftazidime-avibactam exposure on the epidemic OXA-48 plasmid indicate that the evolution of ceftazidime-avibactam resistance comes with collateral effects.
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19
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van Loo B, Bayer CD, Fischer G, Jonas S, Valkov E, Mohamed MF, Vorobieva A, Dutruel C, Hyvönen M, Hollfelder F. Balancing Specificity and Promiscuity in Enzyme Evolution: Multidimensional Activity Transitions in the Alkaline Phosphatase Superfamily. J Am Chem Soc 2018; 141:370-387. [PMID: 30497259 DOI: 10.1021/jacs.8b10290] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Highly proficient, promiscuous enzymes can be springboards for functional evolution, able to avoid loss of function during adaptation by their capacity to promote multiple reactions. We employ a systematic comparative study of structure, sequence, and substrate specificity to track the evolution of specificity and reactivity between promiscuous members of clades of the alkaline phosphatase (AP) superfamily. Construction of a phylogenetic tree of protein sequences maps out the likely transition zone between arylsulfatases (ASs) and phosphonate monoester hydrolases (PMHs). Kinetic analysis shows that all enzymes characterized have four chemically distinct phospho- and sulfoesterase activities, with rate accelerations ranging from 1011- to 1017-fold for their primary and 109- to 1012-fold for their promiscuous reactions, suggesting that catalytic promiscuity is widespread in the AP-superfamily. This functional characterization and crystallography reveal a novel class of ASs that is so similar in sequence to known PMHs that it had not been recognized as having diverged in function. Based on analysis of snapshots of catalytic promiscuity "in transition", we develop possible models that would allow functional evolution and determine scenarios for trade-off between multiple activities. For the new ASs, we observe largely invariant substrate specificity that would facilitate the transition from ASs to PMHs via trade-off-free molecular exaptation, that is, evolution without initial loss of primary activity and specificity toward the original substrate. This ability to bypass low activity generalists provides a molecular solution to avoid adaptive conflict.
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Affiliation(s)
- Bert van Loo
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Christopher D Bayer
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Gerhard Fischer
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Stefanie Jonas
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Eugene Valkov
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Mark F Mohamed
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Anastassia Vorobieva
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Celine Dutruel
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Marko Hyvönen
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
| | - Florian Hollfelder
- Department of Biochemistry , University of Cambridge , Cambridge CB2 1GA , United Kingdom
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20
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Evolutionary repurposing of a sulfatase: A new Michaelis complex leads to efficient transition state charge offset. Proc Natl Acad Sci U S A 2018; 115:E7293-E7302. [PMID: 30012610 DOI: 10.1073/pnas.1607817115] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The recruitment and evolutionary optimization of promiscuous enzymes is key to the rapid adaptation of organisms to changing environments. Our understanding of the precise mechanisms underlying enzyme repurposing is, however, limited: What are the active-site features that enable the molecular recognition of multiple substrates with contrasting catalytic requirements? To gain insights into the molecular determinants of adaptation in promiscuous enzymes, we performed the laboratory evolution of an arylsulfatase to improve its initially weak phenylphosphonate hydrolase activity. The evolutionary trajectory led to a 100,000-fold enhancement of phenylphosphonate hydrolysis, while the native sulfate and promiscuous phosphate mono- and diester hydrolyses were only marginally affected (≤50-fold). Structural, kinetic, and in silico characterizations of the evolutionary intermediates revealed that two key mutations, T50A and M72V, locally reshaped the active site, improving access to the catalytic machinery for the phosphonate. Measured transition state (TS) charge changes along the trajectory suggest the creation of a new Michaelis complex (E•S, enzyme-substrate), with enhanced leaving group stabilization in the TS for the promiscuous phosphonate (βleavinggroup from -1.08 to -0.42). Rather than altering the catalytic machinery, evolutionary repurposing was achieved by fine-tuning the molecular recognition of the phosphonate in the Michaelis complex, and by extension, also in the TS. This molecular scenario constitutes a mechanistic alternative to adaptation solely based on enzyme flexibility and conformational selection. Instead, rapid functional transitions between distinct chemical reactions rely on the high reactivity of permissive active-site architectures that allow multiple substrate binding modes.
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21
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Trade-offs with stability modulate innate and mutationally acquired drug resistance in bacterial dihydrofolate reductase enzymes. Biochem J 2018; 475:2107-2125. [PMID: 29871875 DOI: 10.1042/bcj20180249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/04/2018] [Accepted: 06/05/2018] [Indexed: 01/30/2023]
Abstract
Structural stability is a major constraint on the evolution of protein sequences. However, under strong directional selection, mutations that confer novel phenotypes but compromise structural stability of proteins may be permissible. During the evolution of antibiotic resistance, mutations that confer drug resistance often have pleiotropic effects on the structure and function of antibiotic-target proteins, usually essential metabolic enzymes. In the present study, we show that trimethoprim (TMP)-resistant alleles of dihydrofolate reductase from Escherichia coli (EcDHFR) harboring the Trp30Gly, Trp30Arg or Trp30Cys mutations are significantly less stable than the wild-type, making them prone to aggregation and proteolysis. This destabilization is associated with a lower expression level, resulting in a fitness cost and negative epistasis with other TMP-resistant mutations in EcDHFR. Using structure-based mutational analysis, we show that perturbation of critical stabilizing hydrophobic interactions in wild-type EcDHFR enzyme explains the phenotypes of Trp30 mutants. Surprisingly, though crucial for the stability of EcDHFR, significant sequence variation is found at this site among bacterial dihydrofolate reductases (DHFRs). Mutational and computational analyses in EcDHFR and in DHFR enzymes from Staphylococcus aureus and Mycobacterium tuberculosis demonstrate that natural variation at this site and its interacting hydrophobic residues modulates TMP resistance in other bacterial DHFRs as well, and may explain the different susceptibilities of bacterial pathogens to TMP. Our study demonstrates that trade-offs between structural stability and function can influence innate drug resistance as well as the potential for mutationally acquired drug resistance of an enzyme.
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22
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Sharma P, Guptasarma P. Endoglucanase activity at a second site in Pyrococcus furiosus triosephosphate isomerase-Promiscuity or compensation for a metabolic handicap? FEBS Open Bio 2017; 7:1126-1143. [PMID: 28781953 PMCID: PMC5537068 DOI: 10.1002/2211-5463.12249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 03/05/2017] [Accepted: 05/23/2017] [Indexed: 01/16/2023] Open
Abstract
The eight‐stranded (β/α)8 barrel fold known as the Triosephosphate isomerase (TIM) barrel is the most commonly observed fold in enzymes, displaying an eightfold structural symmetry. The sequences and structures of different TIM barrel enzymes suggest that nature exploits the modularity inherent in the eightfold symmetry to generate enzymes with diverse enzymatic activities and, in certain cases, more than one catalytic activity per enzyme. Here, we report the discovery, verification, and characterization of such an additional activity, a novel endoglucanase/cellulase activity in what is otherwise a triosephosphate isomerase from the hyperthermophile archaeon Pyrococcus furiosus (PfuTIM). The activity is seen in two different ranges of temperatures, with one maximum at 40 °C and a second maximum close to 100 °C. The endoglucanase/cellulase activity is inhibited by norharman, a TIM inhibitor, which is suspected to bind at a site different to that of the regular substrate, glyceraldehyde‐3‐phosphate (G3P). However, endoglucanase/cellulose activity is not inhibited either by G3P analogs or by glycine‐scanning mutations involving residues in loops 1, 4, and 6 of PfuTIM, which are known to be important for TIM activity. It appears, therefore, that two different sites on PfuTIM are responsible for the observed TIM and endoglucanase activities. We discuss possible correlations between this discovery and certain unusual features of the glycolytic pathway in P. furiosus. Enzyme Pyrococcus furiosus Triosephosphate isomerase (EC:5.3.1.1)
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Affiliation(s)
- Prerna Sharma
- Department of Biological Sciences Centre for Protein Science Design and Engineering (CPSDE) Indian Institute of Science Education and Research (IISER) Mohali Punjab.,Division of Protein Science and Engineering CSIR- Institute of Microbial Technology Chandigarh India
| | - Purnananda Guptasarma
- Department of Biological Sciences Centre for Protein Science Design and Engineering (CPSDE) Indian Institute of Science Education and Research (IISER) Mohali Punjab.,Division of Protein Science and Engineering CSIR- Institute of Microbial Technology Chandigarh India
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23
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Blaha-Nelson D, Krüger DM, Szeler K, Ben-David M, Kamerlin SCL. Active Site Hydrophobicity and the Convergent Evolution of Paraoxonase Activity in Structurally Divergent Enzymes: The Case of Serum Paraoxonase 1. J Am Chem Soc 2017; 139:1155-1167. [PMID: 28026940 PMCID: PMC5269640 DOI: 10.1021/jacs.6b10801] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
![]()
Serum
paraoxonase 1 (PON1) is a native lactonase capable of promiscuously
hydrolyzing a broad range of substrates, including organophosphates,
esters, and carbonates. Structurally, PON1 is a six-bladed β-propeller
with a flexible loop (residues 70–81) covering the active site.
This loop contains a functionally critical Tyr at position 71. We
have performed detailed experimental and computational analyses of
the role of selected Y71 variants in the active site stability and
catalytic activity in order to probe the role of Y71 in PON1’s
lactonase and organophosphatase activities. We demonstrate that the
impact of Y71 substitutions on PON1’s lactonase activity is
minimal, whereas the kcat for the paraoxonase
activity is negatively perturbed by up to 100-fold, suggesting greater
mutational robustness of the native activity. Additionally, while
these substitutions modulate PON1’s active site shape, volume,
and loop flexibility, their largest effect is in altering the solvent
accessibility of the active site by expanding the active site volume,
allowing additional water molecules to enter. This effect is markedly
more pronounced in the organophosphatase activity than the lactonase
activity. Finally, a detailed comparison of PON1 to other organophosphatases
demonstrates that either a similar “gating loop” or
a highly buried solvent-excluding active site is a common feature
of these enzymes. We therefore posit that modulating the active site
hydrophobicity is a key element in facilitating the evolution of organophosphatase
activity. This provides a concrete feature that can be utilized in
the rational design of next-generation organophosphate hydrolases
that are capable of selecting a specific reaction from a pool of viable
substrates.
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Affiliation(s)
- David Blaha-Nelson
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University , S-751 24 Uppsala, Sweden
| | - Dennis M Krüger
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University , S-751 24 Uppsala, Sweden
| | - Klaudia Szeler
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University , S-751 24 Uppsala, Sweden
| | - Moshe Ben-David
- Department of Biological Chemistry, Weizmann Institute of Science , Rehovot 76100, Israel
| | - Shina Caroline Lynn Kamerlin
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University , S-751 24 Uppsala, Sweden
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