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Sanfaçon H, Skern T. AlphaFold modeling of nepovirus 3C-like proteinases provides new insights into their diverse substrate specificities. Virology 2024; 590:109956. [PMID: 38052140 DOI: 10.1016/j.virol.2023.109956] [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: 07/03/2023] [Revised: 11/10/2023] [Accepted: 11/24/2023] [Indexed: 12/07/2023]
Abstract
The majority of picornaviral 3C proteinases (3Cpro) cleavage sites possess glutamine at the P1 position. Plant nepovirus 3C-like proteinases (3CLpro) show however much broader specificity, cleaving not only after glutamine, but also after several basic and hydrophobic residues. To investigate this difference, we employed AlphaFold to generate structural models of twelve selected 3CLpro, representing six substrate specificities. Generally, we observed favorable correlations between the architecture and charge of nepovirus proteinase S1 subsites and their ability to accept or restrict larger residues. The models identified a conserved aspartate residue close to the P1 residue in the S1 subsites of all nepovirus proteinases examined, consistent with the observed strong bias against negatively-charged residues at the P1 position of nepovirus cleavage sites. Finally, a cramped S4 subsite along with the presence of two unique histidine and serine residues explains the strict requirement of the grapevine fanleaf virus proteinase for serine at the P4 position.
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Affiliation(s)
- Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, 4200 Highway 97, V0H 1Z0, Summerland, BC, Canada.
| | - Tim Skern
- Department of Medical Biochemistry, Max Perutz Labs, Vienna Biocenter, Medical University of Vienna, A-1030, Vienna, Austria.
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2
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Miyamoto M, Himeda T, Ishihara K, Okuwa T, Kobayashi D, Nameta M, Karasawa Y, Chunhaphinyokul B, Yoshida Y, Tanaka N, Higuchi M, Komuro A. Theilovirus 3C Protease Cleaves the C-Terminal Domain of the Innate Immune RNA Sensor, Melanoma Differentiation-Associated Gene 5, and Impairs Double-Stranded RNA-Mediated IFN Response. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:335-347. [PMID: 36525065 DOI: 10.4049/jimmunol.2200565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/09/2022] [Indexed: 01/04/2023]
Abstract
Melanoma differentiation-associated gene 5 (MDA5), a member of the retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), has pivotal roles in innate immune responses against many positive-stranded RNA viruses, including picornavirus and coronavirus. Upon engagement with dsRNA derived from viral infection, MDA5 initiates coordinated signal transduction leading to type I IFN induction to restrict viral replication. In this study, we describe a targeted cleavage events of MDA5 by the 3C protease from Theilovirus. Upon ectopic expression of theilovirus 3C protease from Saffold virus or Theiler's murine encephalomyelitis virus but not encephalomyocarditis virus, fragments of cleaved MDA5 were observed in a dose-dependent manner. When enzymatically inactive Theilovirus 3C protease was expressed, MDA5 cleavage was completely abrogated. Mass spectrometric analysis identified two cleavage sites at the C terminus of MDA5, cleaving off one of the RNA-binding domains. The same cleavage pattern was observed during Theilovirus infection. The cleavage of MDA5 by Theilovirus protease impaired ATP hydrolysis, RNA binding, and filament assembly on RNA, resulting in dysfunction of MDA5 as an innate immune RNA sensor for IFN induction. Furthermore, the cleavage-resistant MDA5 mutant against the 3C protease showed an enhanced IFN response during Saffold virus infection, indicating that Theilovirus has a strategy to circumvent the antiviral immune response by cleaving MDA5 using 3C protease. In summary, these data suggest MDA5 cleavage by 3C protease as a novel immune evasive strategy of Theilovirus.
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Affiliation(s)
- Masahiko Miyamoto
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Toshiki Himeda
- Department of Microbiology, Kanazawa Medical University School of Medicine, Ishikawa, Japan
| | - Kazuki Ishihara
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Takako Okuwa
- Department of Microbiology, Kanazawa Medical University School of Medicine, Ishikawa, Japan
| | - Daiki Kobayashi
- Omics Unit, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Masaaki Nameta
- Electron Microscope Core Facility, Niigata University, Niigata, Japan
| | - Yu Karasawa
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Benyapa Chunhaphinyokul
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Yutaka Yoshida
- Department of Structural Pathology, Kidney Research Center, Niigata University, Niigata, Japan; and
| | - Nobuyuki Tanaka
- Division of Tumor Immunology, Miyagi Cancer Center Research Institute, Medeshima-Shiode, Natori, Miyagi, Japan
| | - Masaya Higuchi
- Department of Microbiology, Kanazawa Medical University School of Medicine, Ishikawa, Japan
| | - Akihiko Komuro
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
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3
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Kidera A, Moritsugu K, Ekimoto T, Ikeguchi M. Functional dynamics of SARS-CoV-2 3C-like protease as a member of clan PA. Biophys Rev 2022; 14:1473-1485. [PMID: 36474932 PMCID: PMC9716165 DOI: 10.1007/s12551-022-01020-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
SARS-CoV-2 3C-like protease (3CLpro), a potential therapeutic target for COVID-19, consists of a chymotrypsin fold and a C-terminal α-helical domain (domain III), the latter of which mediates dimerization required for catalytic activation. To gain further understanding of the functional dynamics of SARS-CoV-2 3CLpro, this review extends the scope to the comparative study of many crystal structures of proteases having the chymotrypsin fold (clan PA of the MEROPS database). First, the close correspondence between the zymogen-enzyme transformation in chymotrypsin and the allosteric dimerization activation in SARS-CoV-2 3CLpro is illustrated. Then, it is shown that the 3C-like proteases of family Coronaviridae (the protease family C30), which are closely related to SARS-CoV-2 3CLpro, have the same homodimeric structure and common activation mechanism via domain III mediated dimerization. The survey extended to order Nidovirales reveals that all 3C-like proteases belonging to Nidovirales have domain III, but with various chain lengths, and 3CLpro of family Mesoniviridae (family C107) has the same homodimeric structure as that of C30, even though they have no sequence similarity. As a reference, monomeric 3C proteases belonging to the more distant family Picornaviridae (family C3) lacking domain III are compared with C30, and it is shown that the 3C proteases are rigid enough to maintain their structures in the active state. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-022-01020-x.
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Affiliation(s)
- Akinori Kidera
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi, Yokohama 230-0045 Japan
| | - Kei Moritsugu
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi, Yokohama 230-0045 Japan ,Present Address: Graduate School of Science, Osaka Metropolitan University, 1-1 Gakuen-Cho, Nakaku, Sakai, Osaka 599-8570 Japan
| | - Toru Ekimoto
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi, Yokohama 230-0045 Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-Cho, Tsurumi, Yokohama 230-0045 Japan
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4
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Rius J, Torrelles X. Extending the novel |ρ|-based phasing algorithm to the solution of anomalous scattering substructures from SAD data of protein crystals. ACTA CRYSTALLOGRAPHICA SECTION A FOUNDATIONS AND ADVANCES 2022; 78:473-481. [DOI: 10.1107/s2053273322008622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/29/2022] [Indexed: 11/07/2022]
Abstract
Owing to the importance of the single-wavelength anomalous diffraction (SAD) technique, the recently developed |ρ|-based phasing algorithm (S
M,|ρ|) incorporating the inner-pixel preservation (ipp) procedure [Rius & Torrelles (2021). Acta Cryst A77, 339–347] has been adapted to the determination of anomalous scattering substructures and its applicability tested on a series of 12 representative experimental data sets, mostly retrieved from the Protein Data Bank. To give an idea of the suitability of the data sets, the main indicators measuring their quality are also given. The dominant anomalous scatterers are either SeMet or S atoms, or metals/clusters incorporated by soaking. The resulting SAD-adapted algorithm solves the substructures of the test protein crystals quite efficiently.
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Bafna K, Cioffi CL, Krug RM, Montelione GT. Structural similarities between SARS-CoV2 3CL pro and other viral proteases suggest potential lead molecules for developing broad spectrum antivirals. Front Chem 2022; 10:948553. [PMID: 36353143 PMCID: PMC9638714 DOI: 10.3389/fchem.2022.948553] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/08/2022] [Indexed: 09/01/2023] Open
Abstract
Considering the significant impact of the recent COVID-19 outbreak, development of broad-spectrum antivirals is a high priority goal to prevent future global pandemics. Antiviral development processes generally emphasize targeting a specific protein from a particular virus. However, some antiviral agents developed for specific viral protein targets may exhibit broad spectrum antiviral activity, or at least provide useful lead molecules for broad spectrum drug development. There is significant potential for repurposing a wide range of existing viral protease inhibitors to inhibit the SARS-CoV2 3C-like protease (3CLpro). If effective even as relatively weak inhibitors of 3CLpro, these molecules can provide a diverse and novel set of scaffolds for new drug discovery campaigns. In this study, we compared the sequence- and structure-based similarity of SARS-CoV2 3CLpro with proteases from other viruses, and identified 22 proteases with similar active-site structures. This structural similarity, characterized by secondary-structure topology diagrams, is evolutionarily divergent within taxonomically related viruses, but appears to result from evolutionary convergence of protease enzymes between virus families. Inhibitors of these proteases that are structurally similar to the SARS-CoV2 3CLpro protease were identified and assessed as potential inhibitors of SARS-CoV2 3CLpro protease by virtual docking. Several of these molecules have docking scores that are significantly better than known SARS-CoV2 3CLpro inhibitors, suggesting that these molecules are also potential inhibitors of the SARS-CoV2 3CLpro protease. Some have been previously reported to inhibit SARS-CoV2 3CLpro. The results also suggest that established inhibitors of SARS-CoV2 3CLpro may be considered as potential inhibitors of other viral 3C-like proteases.
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Affiliation(s)
- Khushboo Bafna
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Christopher L. Cioffi
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Robert M. Krug
- Department of Molecular Biosciences, John Ring LaMontagne Center for Infectious Disease, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, United States
| | - Gaetano T. Montelione
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States
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6
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Hu Q, Xiong Y, Zhu GH, Zhang YN, Zhang YW, Huang P, Ge GB. The SARS-CoV-2 main protease (M pro): Structure, function, and emerging therapies for COVID-19. MedComm (Beijing) 2022; 3:e151. [PMID: 35845352 PMCID: PMC9283855 DOI: 10.1002/mco2.151] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 12/21/2022] Open
Abstract
The main proteases (Mpro), also termed 3‐chymotrypsin‐like proteases (3CLpro), are a class of highly conserved cysteine hydrolases in β‐coronaviruses. Increasing evidence has demonstrated that 3CLpros play an indispensable role in viral replication and have been recognized as key targets for preventing and treating coronavirus‐caused infectious diseases, including COVID‐19. This review is focused on the structural features and biological function of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) main protease Mpro (also known as 3CLpro), as well as recent advances in discovering and developing SARS‐CoV‐2 3CLpro inhibitors. To better understand the characteristics of SARS‐CoV‐2 3CLpro inhibitors, the inhibition activities, inhibitory mechanisms, and key structural features of various 3CLpro inhibitors (including marketed drugs, peptidomimetic, and non‐peptidomimetic synthetic compounds, as well as natural compounds and their derivatives) are summarized comprehensively. Meanwhile, the challenges in this field are highlighted, while future directions for designing and developing efficacious 3CLpro inhibitors as novel anti‐coronavirus therapies are also proposed. Collectively, all information and knowledge presented here are very helpful for understanding the structural features and inhibitory mechanisms of SARS‐CoV‐2 3CLpro inhibitors, which offers new insights or inspiration to medicinal chemists for designing and developing more efficacious 3CLpro inhibitors as novel anti‐coronavirus agents.
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Affiliation(s)
- Qing Hu
- Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai China.,Clinical Pharmacy Center Cancer Center Department of Pharmacy Zhejiang Provincial People's Hospital Affiliated People's Hospital Hangzhou Medical College, Hangzhou Zhejiang China
| | - Yuan Xiong
- Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai China
| | - Guang-Hao Zhu
- Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai China
| | - Ya-Ni Zhang
- Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai China
| | - Yi-Wen Zhang
- Clinical Pharmacy Center Cancer Center Department of Pharmacy Zhejiang Provincial People's Hospital Affiliated People's Hospital Hangzhou Medical College, Hangzhou Zhejiang China
| | - Ping Huang
- Clinical Pharmacy Center Cancer Center Department of Pharmacy Zhejiang Provincial People's Hospital Affiliated People's Hospital Hangzhou Medical College, Hangzhou Zhejiang China
| | - Guang-Bo Ge
- Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai China
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7
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Denesyuk AI, Permyakov SE, Johnson MS, Permyakov EA, Uversky VN, Denessiouk K. Structural leitmotif and functional variations of the structural catalytic core in (chymo)trypsin-like serine/cysteine fold proteinases. Int J Biol Macromol 2021; 179:601-609. [PMID: 33713772 DOI: 10.1016/j.ijbiomac.2021.03.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 11/29/2022]
Abstract
Proteinases with the (chymo)trypsin-like serine/cysteine fold comprise a large superfamily performing their function through the Acid - Base - Nucleophile catalytic triad. In our previous work (Denesyuk AI, Johnson MS, Salo-Ahen OMH, Uversky VN, Denessiouk K. Int J Biol Macromol. 2020;153:399-411), we described a universal three-dimensional (3D) structural motif, NBCZone, that contains eleven amino acids: dipeptide 42 T-43 T, pentapeptide 54 T-55 T-56 T-57 T(base)-58 T, tripeptide 195 T(nucleophile)-196 T-197 T and residue 213 T (T - numeration of amino acids in trypsin). The comparison of the NBCZones among the members of the (chymo)trypsin-like protease family suggested the existence of 15 distinct groups. Within each group, the NBCZones incorporate an identical set of conserved interactions and bonds. In the present work, the structural environment of the catalytic acid at the position 102 T and the fourth member of the "catalytic tetrad" at the position 214 T was analyzed in 169 3D structures of proteinases with the (chymo)trypsin-like serine/cysteine fold. We have identified a complete Structural Catalytic Core (SCC) consisting of two classes and four groups. The proteinases belonging to different classes and groups differ from each other by the nature of the interaction between their N- and C-terminal β-barrels. Comparative analysis of the 3CLpro(s) from SARS-CoV-2 and SARS-CoV, used as an example, showed that the amino acids at positions 103 T and 179 T affect the nature of the interaction of the "catalytic acid" core (102 T-Core, N-terminal β-barrel) with the "supplementary" core (S-Core, C-terminal β-barrel), which ultimately results in the modulation of the enzymatic activity. The reported analysis represents an important standalone contribution to the analysis and systematization of the 3D structures of (chymo)trypsin-like serine/cysteine fold proteinases. The use of the developed approach for the comparison of 3D structures will allow, in the event of the appearance of new representatives of a given fold in the PDB, to quickly determine their structural homologues with the identification of possible differences.
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Affiliation(s)
- Alexander I Denesyuk
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region 142290, Russia; Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku 20520, Finland.
| | - Sergei E Permyakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region 142290, Russia
| | - Mark S Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku 20520, Finland
| | - Eugene A Permyakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region 142290, Russia
| | - Vladimir N Uversky
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region 142290, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku 20520, Finland
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Gulyaeva AA, Gorbalenya AE. A nidovirus perspective on SARS-CoV-2. Biochem Biophys Res Commun 2020; 538:24-34. [PMID: 33413979 PMCID: PMC7664520 DOI: 10.1016/j.bbrc.2020.11.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023]
Abstract
Two pandemics of respiratory distress diseases associated with zoonotic introductions of the species Severe acute respiratory syndrome-related coronavirus in the human population during 21st century raised unprecedented interest in coronavirus research and assigned it unseen urgency. The two viruses responsible for the outbreaks, SARS-CoV and SARS-CoV-2, respectively, are in the spotlight, and SARS-CoV-2 is the focus of the current fast-paced research. Its foundation was laid down by studies of many corona- and related viruses that collectively form the vast order Nidovirales. Comparative genomics of nidoviruses played a key role in this advancement over more than 30 years. It facilitated the transfer of knowledge from characterized to newly identified viruses, including SARS-CoV and SARS-CoV-2, as well as contributed to the dissection of the nidovirus proteome and identification of patterns of variations between different taxonomic groups, from species to families. This review revisits selected cases of protein conservation and variation that define nidoviruses, illustrates the remarkable plasticity of the proteome during nidovirus adaptation, and asks questions at the interface of the proteome and processes that are vital for nidovirus reproduction and could inform the ongoing research of SARS-CoV-2.
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Affiliation(s)
- Anastasia A Gulyaeva
- Department of Medical Microbiology, Leiden University Medical Center, 2300 RC, Leiden, the Netherlands
| | - Alexander E Gorbalenya
- Department of Medical Microbiology, Leiden University Medical Center, 2300 RC, Leiden, the Netherlands; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119899, Moscow, Russia.
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Characterization of Self-Processing Activities and Substrate Specificities of Porcine Torovirus 3C-Like Protease. J Virol 2020; 94:JVI.01282-20. [PMID: 32727876 DOI: 10.1128/jvi.01282-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/24/2020] [Indexed: 12/17/2022] Open
Abstract
The 3C-like protease (3CLpro) of nidovirus plays an important role in viral replication and manipulation of host antiviral innate immunity, which makes it an ideal antiviral target. Here, we characterized that porcine torovirus (PToV; family Tobaniviridae, order Nidovirales) 3CLpro autocatalytically releases itself from the viral precursor protein by self-cleavage. Site-directed mutagenesis suggested that PToV 3CLpro, as a serine protease, employed His53 and Ser160 as the active-site residues. Interestingly, unlike most nidovirus 3CLpro, the P1 residue plays a less essential role in N-terminal self-cleavage of PToV 3CLpro Substituting either P1 or P4 residue of substrate alone has little discernible effect on N-terminal cleavage. Notably, replacement of the two residues together completely blocks N-terminal cleavage, suggesting that N-terminal self-cleavage of PToV 3CLpro is synergistically affected by both P1 and P4 residues. Using a cyclized luciferase-based biosensor, we systematically scanned the polyproteins for cleavage sites and identified (FXXQ↓A/S) as the main consensus sequences. Subsequent homology modeling and biochemical experiments suggested that the protease formed putative pockets S1 and S4 between the substrate. Indeed, mutants of both predicted S1 (D159A, H174A) and S4 (P62G/L185G) pockets completely lost the ability of cleavage activity of PToV 3CLpro In conclusion, the characterization of self-processing activities and substrate specificities of PToV 3CLpro will offer helpful information for the mechanism of nidovirus 3C-like proteinase's substrate specificities and the rational development of the antinidovirus drugs.IMPORTANCE Currently, the active-site residues and substrate specificities of 3C-like protease (3CLpro) differ among nidoviruses, and the detailed catalytic mechanism remains largely unknown. Here, porcine torovirus (PToV) 3CLpro cleaves 12 sites in the polyproteins, including its N- and C-terminal self-processing sites. Unlike coronaviruses and arteriviruses, PToV 3CLpro employed His53 and Ser160 as the active-site residues that recognize a glutamine (Gln) at the P1 position. Surprisingly, mutations of P1-Gln impaired the C-terminal self-processing but did not affect N-terminal self-processing. The "noncanonical" substrate specificity for its N-terminal self-processing was attributed to the phenylalanine (Phe) residue at the P4 position in the N-terminal site. Furthermore, a double glycine (neutral) substitution at the putative P4-Phe-binding residues (P62G/L185G) abolished the cleavage activity of PToV 3CLpro suggested the potential hydrophobic force between the PToV 3CLpro and P4-Phe side chains.
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Denesyuk AI, Johnson MS, Salo-Ahen OMH, Uversky VN, Denessiouk K. NBCZone: Universal three-dimensional construction of eleven amino acids near the catalytic nucleophile and base in the superfamily of (chymo)trypsin-like serine fold proteases. Int J Biol Macromol 2020; 153:399-411. [PMID: 32151723 PMCID: PMC7124590 DOI: 10.1016/j.ijbiomac.2020.03.025] [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: 10/25/2019] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 10/25/2022]
Abstract
(Chymo)trypsin-like serine fold proteases belong to the serine/cysteine proteases found in eukaryotes, prokaryotes, and viruses. Their catalytic activity is carried out using a triad of amino acids, a nucleophile, a base, and an acid. For this superfamily of proteases, we propose the existence of a universal 3D structure comprising 11 amino acids near the catalytic nucleophile and base - Nucleophile-Base Catalytic Zone (NBCZone). The comparison of NBCZones among 169 eukaryotic, prokaryotic, and viral (chymo)trypsin-like proteases suggested the existence of 15 distinct groups determined by the combination of amino acids located at two "key" structure-functional positions 54T and 55T near the catalytic base His57T. Most eukaryotic and prokaryotic proteases fell into two major groups, [ST]A and TN. Usually, proteases of [ST]A group contain a disulfide bond between cysteines Cys42T and Cys58T of the NBCZone. In contrast, viral proteases were distributed among seven groups, and lack this disulfide bond. Furthermore, only the [ST]A group of eukaryotic proteases contains glycine at position 43T, which is instrumental for activation of these enzymes. In contrast, due to the side chains of residues at position 43T prokaryotic and viral proteases do not have the ability to carry out the structural transition of the eukaryotic zymogen-zyme type.
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Affiliation(s)
- Alexander I Denesyuk
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Russia; Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland.
| | - Mark S Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - Outi M H Salo-Ahen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland; Pharmaceutical Sciences Laboratory, Pharmacy, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - Vladimir N Uversky
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland; Pharmaceutical Sciences Laboratory, Pharmacy, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
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