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An Y, Chatterjee P, Naik P, Banerjee S, Huang W, Slowing II, Venditti V. Hydrogen spillover and substrate-support hydrogen bonding mediate hydrogenation of phenol catalyzed by palladium on reducible metal oxides. Chem Sci 2023; 14:14166-14175. [PMID: 38098721 PMCID: PMC10717535 DOI: 10.1039/d3sc02913a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/09/2023] [Indexed: 12/17/2023] Open
Abstract
Substrate-support interactions play an important role in the catalytic hydrogenation of phenolic compounds by ceria-supported palladium (Pd/CeO2). Here, we combine surface contrast solution NMR methods and reaction kinetic assays to investigate the role of substrate-support interactions in phenol (PhOH) hydrogenation catalyzed by titania-supported palladium (Pd/TiO2). We show that PhOH adsorbs on the catalyst via a weak hydrogen-bonding interaction between the -OH group of the substrate and one oxygen atom on the support. Interestingly, we observe that the addition of 20 mM inorganic phosphate results in a ∼2-fold destabilization of the PhOH-support interaction and a corresponding ∼2-fold inhibition of the catalytic reaction, suggesting an active role of the PhOH-TiO2 hydrogen bond in catalysis. A comparison of the data measured here with the results previously reported for a Pd/CeO2 catalyst indicates that the efficiency of the Pd-supported catalysts is correlated to the amount of PhOH hydrogen bonded to the metal oxide support. Since CeO2 and TiO2 have similar ability to uptake activated hydrogen from a noble metal site, these data suggest that hydrogen spillover is the main mechanism by which Pd-activated hydrogens are shuttled to the PhOH adsorbed on the surface of the support. Consistent with this hypothesis, Pd supported on a non-reducible metal oxide (silica) displays negligible hydrogenation activity. Therefore, we conclude that basic and reducible metal oxides are active supports for the efficient hydrogenation of phenolic compounds due to their ability to hydrogen bond to the substrate and mediate the addition of the activated hydrogens to the adsorbed aromatic ring.
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Affiliation(s)
- Yeongseo An
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Puranjan Chatterjee
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Pranjali Naik
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Sayak Banerjee
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Wenyu Huang
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Igor I Slowing
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Department of Energy, Ames Laboratory Ames Iowa 50011 USA
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University Ames Iowa 50011 USA
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Pegram L, Riccardi D, Ahn N. Activation Loop Plasticity and Active Site Coupling in the MAP Kinase, ERK2. J Mol Biol 2023; 435:168309. [PMID: 37806554 PMCID: PMC10676806 DOI: 10.1016/j.jmb.2023.168309] [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: 04/15/2023] [Revised: 09/03/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
Previous studies of the protein kinase, ERK2, using NMR and hydrogen-exchange measurements have shown changes in dynamics accompanying its activation by phosphorylation. However, knowledge about the conformational motions involved is incomplete. Here, we examined ERK2 using long conventional molecular dynamics (MD) simulations starting from crystal structures of phosphorylated (2P) and unphosphorylated (0P) forms. Individual trajectories were run for (5 to 25) μs, totaling 727 μs. The results show unexpected flexibility of the A-loop, with multiple long-lived (>5 μs) conformational states in both 2P- and 0P-ERK2. Differential contact network and principal component analyses reveal coupling between the A-loop fold and active site dynamics, with evidence for conformational selection in the kinase core of 2P-ERK2 but not 0P-ERK2. Simulations of 2P-ERK2 show A-loop states corresponding to restrained dynamics within the N-lobe, including regions around catalytic residues. One A-loop conformer forms lasting interactions with the L16 segment, leading to reduced RMSF and greater compaction in the active site. By contrast, simulations of 0P-ERK2 reveal excursions of A-loop residues away from the C-lobe, leading to greater active site mobility. Thus, the A-loop in ERK2 switches between distinct conformations that reflect coupling with the active site, possibly via the L16 segment. Crystal packing interactions suggest that lattice contacts with the A-loop may restrain its structural variation in X-ray structures of ERK2. The novel conformational states identified by MD expand our understanding of ERK2 regulation, by linking the activated state of the kinase to reduced dynamics and greater compaction surrounding the catalytic site.
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Affiliation(s)
- Laurel Pegram
- Department of Biochemistry, University of Colorado, Boulder, CO 80305, USA
| | - Demian Riccardi
- Thermodynamics Research Center, Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, CO, USA
| | - Natalie Ahn
- Department of Biochemistry, University of Colorado, Boulder, CO 80305, USA.
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Pegram L, Riccardi D, Ahn N. Activation loop plasticity and active site coupling in the MAP kinase, ERK2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.15.537040. [PMID: 37090603 PMCID: PMC10120733 DOI: 10.1101/2023.04.15.537040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Changes in the dynamics of the protein kinase, ERK2, have been shown to accompany its activation by dual phosphorylation. However, our knowledge about the conformational changes represented by these motions is incomplete. Previous NMR relaxation dispersion studies showed that active, dual-phosphorylated ERK2 undergoes global exchange between at least two energetically similar conformations. These findings, combined with measurements by hydrogen exchange mass spectrometry (HX-MS), suggested that the global conformational exchange involves motions of the activation loop (A-loop) that are coupled to regions surrounding the kinase active site. In order to better understand the contribution of dynamics to the activation of ERK2, we applied long conventional molecular dynamics (MD) simulations starting from crystal structures of active, phosphorylated (2P), and inactive, unphosphorylated (0P) ERK2. Individual trajectories were run for (5 to 25) µ s and totaled 727 µ s. The results showed that the A-loop is unexpectedly flexible in both 2P- and 0P-ERK2, and able to adopt multiple long-lived (>5 µ s) conformational states. Simulations starting from the X-ray structure of 2P-ERK2 (2ERK) revealed A-loop states corresponding to restrained dynamics within the N-lobe, including regions surrounding catalytic residues. One A-loop conformer forms lasting interactions with the C-terminal L16 segment and shows reduced RMSF and greater compaction in the active site. By contrast, simulations starting from the most common X-ray conformation of 0P-ERK2 (5UMO) reveal frequent excursions of A-loop residues away from a C-lobe docking site pocket and towards a new state that shows greater dynamics in the N-lobe and disorganization around the active site. Thus, the A-loop in ERK2 appears to switch between distinct conformational states that reflect allosteric coupling with the active site, likely occurring via the L16 segment. Analyses of crystal packing interactions across many structural datasets suggest that the A-loop observed in X-ray structures of ERK2 may be driven by lattice contacts and less representative of the solution structure. The novel conformational states identified by MD expand our understanding of ERK2 regulation, by linking the activated state of the kinase to reduced dynamics and greater compaction surrounding the catalytic site.
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4
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Tartaglia M, Aoki Y, Gelb BD. The molecular genetics of RASopathies: An update on novel disease genes and new disorders. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:425-439. [PMID: 36394128 PMCID: PMC10100036 DOI: 10.1002/ajmg.c.32012] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/31/2022] [Accepted: 11/05/2022] [Indexed: 11/18/2022]
Abstract
Enhanced signaling through RAS and the mitogen-associated protein kinase (MAPK) cascade underlies the RASopathies, a family of clinically related disorders affecting development and growth. In RASopathies, increased RAS-MAPK signaling can result from the upregulated activity of various RAS GTPases, enhanced function of proteins positively controlling RAS function or favoring the efficient transmission of RAS signaling to downstream transducers, functional upregulation of RAS effectors belonging to the MAPK cascade, or inefficient signaling switch-off operated by feedback mechanisms acting at different levels. The massive effort in RASopathy gene discovery performed in the last 20 years has identified more than 20 genes implicated in these disorders. It has also facilitated the characterization of several molecular activating mechanisms that had remained unappreciated due to their minor impact in oncogenesis. Here, we provide an overview on the discoveries collected during the last 5 years that have delivered unexpected insights (e.g., Noonan syndrome as a recessive disease) and allowed to profile new RASopathies, novel disease genes and new molecular circuits contributing to the control of RAS-MAPK signaling.
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Affiliation(s)
- Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Japan
| | - Bruce D Gelb
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Pediatrics and Genetics, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Cognitive Deficits Found in a Pro-inflammatory State are Independent of ERK1/2 Signaling in the Murine Brain Hippocampus Treated with Shiga Toxin 2 from Enterohemorrhagic Escherichia coli. Cell Mol Neurobiol 2022:10.1007/s10571-022-01298-1. [PMID: 36227397 DOI: 10.1007/s10571-022-01298-1] [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: 03/14/2022] [Accepted: 10/05/2022] [Indexed: 11/03/2022]
Abstract
Shiga toxin 2 (Stx2) from enterohemorrhagic Escherichia coli (EHEC) produces hemorrhagic colitis, hemolytic uremic syndrome (HUS), and acute encephalopathy. The mortality rate in HUS increases significantly when the central nervous system (CNS) is involved. Besides, EHEC also releases lipopolysaccharide (LPS). Many reports have described cognitive dysfunctions in HUS patients, the hippocampus being one of the brain areas targeted by EHEC infection. In this context, a translational murine model of encephalopathy was employed to establish the deleterious effects of Stx2 and the contribution of LPS in the hippocampus. The purpose of this work is to elucidate the signaling pathways that may activate the inflammatory processes triggered by Stx2, which produces cognitive alterations at the level of the hippocampus. Results demonstrate that Stx2 produced depression-like behavior, pro-inflammatory cytokine release, and NF-kB activation independent of the ERK1/2 signaling pathway, while co-administration of Stx2 and LPS reduced memory index. On the other hand, LPS activated NF-kB dependent on ERK1/2 signaling pathway. Cotreatment of Stx2 with LPS aggravated the pathologic state, while dexamethasone treatment succeeded in preventing behavioral alterations. Our present work suggests that the use of drugs such as corticosteroids or NF-kB signaling inhibitors may serve as neuroprotectors from EHEC infection.
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Ndathe R, Dale R, Kato N. Dynamic modeling of ABA-dependent expression of the Arabidopsis RD29A gene. FRONTIERS IN PLANT SCIENCE 2022; 13:928718. [PMID: 36092424 PMCID: PMC9458874 DOI: 10.3389/fpls.2022.928718] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/02/2022] [Indexed: 06/01/2023]
Abstract
The abscisic acid (ABA) signaling pathway is the key defense mechanism against drought stress in plants. In the pathway, signal transduction among four core proteins, pyrabactin resistance (PYR), protein phosphatase 2C (PP2C), sucrose-non-fermenting-1-related protein kinase 2 (SnRK2), and ABRE binding factor (ABF) leads to altered gene expression kinetics that is driven by an ABA-responsive element (ABRE). A most recent and comprehensive study provided data suggesting that ABA alters the expression kinetics in over 6,500 genes through the ABF-ABRE associations in Arabidopsis. Of these genes, termed ABA gene regulatory network (GRN), over 50% contain a single ABRE within 4 kb of the gene body, despite previous findings suggesting that a single copy of ABRE is not sufficient to drive the gene expression. To understand the expression system of the ABA GRN by the single ABRE, a dynamic model of the gene expression for the desiccation 29A (RD29A) gene was constructed with ordinary differential equations. Parameter values of molecular-molecular interactions and enzymatic reactions in the model were implemented from the data obtained by previously conducted in vitro experiments. On the other hand, parameter values of gene expression and translation were determined by comparing the kinetics of gene expression in the model to the expression kinetics of RD29A in real plants. The optimized model recapitulated the trend of gene expression kinetics of RD29A in ABA dose-response that were previously investigated. Further analysis of the model suggested that a single ABRE controls the time scale and dynamic range of the ABA-dependent gene expression through the PP2C feedback regulation even though an additional cis-element is required to drive the expression. The model construed in this study underpins the importance of a single ABRE in the ABA GRN.
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Affiliation(s)
- Ruth Ndathe
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Renee Dale
- Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Naohiro Kato
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
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Olivieri C, Li GC, Wang Y, V.S. M, Walker C, Kim J, Camilloni C, De Simone A, Vendruscolo M, Bernlohr DA, Taylor SS, Veglia G. ATP-competitive inhibitors modulate the substrate binding cooperativity of a kinase by altering its conformational entropy. SCIENCE ADVANCES 2022; 8:eabo0696. [PMID: 35905186 PMCID: PMC9337769 DOI: 10.1126/sciadv.abo0696] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
ATP-competitive inhibitors are currently the largest class of clinically approved drugs for protein kinases. By targeting the ATP-binding pocket, these compounds block the catalytic activity, preventing substrate phosphorylation. A problem with these drugs, however, is that inhibited kinases may still recognize and bind downstream substrates, acting as scaffolds or binding hubs for signaling partners. Here, using protein kinase A as a model system, we show that chemically different ATP-competitive inhibitors modulate the substrate binding cooperativity by tuning the conformational entropy of the kinase and shifting the populations of its conformationally excited states. Since we found that binding cooperativity and conformational entropy of the enzyme are correlated, we propose a new paradigm for the discovery of ATP-competitive inhibitors, which is based on their ability to modulate the allosteric coupling between nucleotide and substrate-binding sites.
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Affiliation(s)
- Cristina Olivieri
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Geoffrey C. Li
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yingjie Wang
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Manu V.S.
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Caitlin Walker
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jonggul Kim
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano 20133, Italy
| | - Alfonso De Simone
- Department of Pharmacy, Università degli Studi di Napoli Federico II, Napoli 80131, Italy
| | | | - David A. Bernlohr
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Susan S. Taylor
- Department of Chemistry and Biochemistry, and Pharmacology, University of California at San Diego, CA 92093, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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8
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Purslow JA, Nguyen TT, Khatiwada B, Singh A, Venditti V. N 6-methyladenosine binding induces a metal-centered rearrangement that activates the human RNA demethylase Alkbh5. SCIENCE ADVANCES 2021; 7:7/34/eabi8215. [PMID: 34407931 PMCID: PMC8373141 DOI: 10.1126/sciadv.abi8215] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/29/2021] [Indexed: 05/13/2023]
Abstract
Alkbh5 catalyzes demethylation of the N 6-methyladenosine (m6A), an epigenetic mark that controls several physiological processes including carcinogenesis and stem cell differentiation. The activity of Alkbh5 comprises two coupled reactions. The first reaction involves decarboxylation of α-ketoglutarate (αKG) and formation of a Fe4+═O species. This oxyferryl intermediate oxidizes the m6A to reestablish the canonical base. Despite coupling between the two reactions being required for the correct Alkbh5 functioning, the mechanisms linking dioxygen activation to m6A binding are not fully understood. Here, we use solution NMR to investigate the structure and dynamics of apo and holo Alkbh5. We show that binding of m6A to Alkbh5 induces a metal-centered rearrangement of αKG that increases the exposed area of the metal, making it available for binding O2 Our study reveals the molecular mechanisms underlying activation of Alkbh5, therefore opening new perspectives for the design of novel strategies to control gene expression and cancer progression.
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Affiliation(s)
| | - Trang T Nguyen
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | | | - Aayushi Singh
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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Sok P, Gógl G, Kumar GS, Alexa A, Singh N, Kirsch K, Sebő A, Drahos L, Gáspári Z, Peti W, Reményi A. MAP Kinase-Mediated Activation of RSK1 and MK2 Substrate Kinases. Structure 2020; 28:1101-1113.e5. [PMID: 32649858 DOI: 10.1016/j.str.2020.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/03/2020] [Accepted: 06/22/2020] [Indexed: 11/17/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) control essential eukaryotic signaling pathways. While much has been learned about MAPK activation, much less is known about substrate recruitment and specificity. MAPK substrates may be other kinases that are crucial to promote a further diversification of the signaling outcomes. Here, we used a variety of molecular and cellular tools to investigate the recruitment of two substrate kinases, RSK1 and MK2, to three MAPKs (ERK2, p38α, and ERK5). Unexpectedly, we identified that kinase heterodimers form structurally and functionally distinct complexes depending on the activation state of the MAPK. These may be incompatible with downstream signaling, but naturally they may also form structures that are compatible with the phosphorylation of the downstream kinase at the activation loop, or alternatively at other allosteric sites. Furthermore, we show that small-molecule inhibitors may affect the quaternary arrangement of kinase heterodimers and thus influence downstream signaling in a specific manner.
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Affiliation(s)
- Péter Sok
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | - Gergő Gógl
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | | | - Anita Alexa
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | - Neha Singh
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | - Klára Kirsch
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | - Anna Sebő
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary
| | - László Drahos
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Budapest, Hungary
| | - Zoltán Gáspári
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Wolfgang Peti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, USA
| | - Attila Reményi
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, Magyar Tudósok körútja 2., 1117 Budapest, Hungary.
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Dotas RR, Nguyen TT, Stewart CE, Ghirlando R, Potoyan DA, Venditti V. Hybrid Thermophilic/Mesophilic Enzymes Reveal a Role for Conformational Disorder in Regulation of Bacterial Enzyme I. J Mol Biol 2020; 432:4481-4498. [PMID: 32504625 DOI: 10.1016/j.jmb.2020.05.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/23/2020] [Accepted: 05/29/2020] [Indexed: 02/08/2023]
Abstract
Conformational disorder is emerging as an important feature of biopolymers, regulating a vast array of cellular functions, including signaling, phase separation, and enzyme catalysis. Here we combine NMR, crystallography, computer simulations, protein engineering, and functional assays to investigate the role played by conformational heterogeneity in determining the activity of the C-terminal domain of bacterial Enzyme I (EIC). In particular, we design chimeric proteins by hybridizing EIC from thermophilic and mesophilic organisms, and we characterize the resulting constructs for structure, dynamics, and biological function. We show that EIC exists as a mixture of active and inactive conformations and that functional regulation is achieved by tuning the thermodynamic balance between active and inactive states. Interestingly, we also present a hybrid thermophilic/mesophilic enzyme that is thermostable and more active than the wild-type thermophilic enzyme, suggesting that hybridizing thermophilic and mesophilic proteins is a valid strategy to engineer thermostable enzymes with significant low-temperature activity.
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Affiliation(s)
- Rochelle R Dotas
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Trang T Nguyen
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Charles E Stewart
- Macromolecular X-ray Crystallography Facility, Office of Biotechnology, Iowa State University, Ames, IA 50011, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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