1
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Perlinska AP, Sikora M, Sulkowska JI. Everything AlphaFold tells us about protein knots. J Mol Biol 2024; 436:168715. [PMID: 39029890 DOI: 10.1016/j.jmb.2024.168715] [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: 05/06/2024] [Revised: 06/29/2024] [Accepted: 07/14/2024] [Indexed: 07/21/2024]
Abstract
Recent advances in Machine Learning methods in structural biology opened up new perspectives for protein analysis. Utilizing these methods allows us to go beyond the limitations of empirical research, and take advantage of the vast amount of generated data. We use a complete set of potentially knotted protein models identified in all high-quality predictions from the AlphaFold Database to search for any common trends that describe them. We show that the vast majority of knotted proteins have 31 knot and that the presence of knots is preferred in neither Bacteria, Eukaryota, or Archaea domains. On the contrary, the percentage of knotted proteins in any given proteome is around 0.4%, regardless of the taxonomical group. We also verified that the organism's living conditions do not impact the number of knotted proteins in its proteome, as previously expected. We did not encounter an organism without a single knotted protein. What is more, we found four universally present families of knotted proteins in Bacteria, consisting of SAM synthase, and TrmD, TrmH, and RsmE methyltransferases.
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Affiliation(s)
- Agata P Perlinska
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland
| | - Maciej Sikora
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland
| | - Joanna I Sulkowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw 02-097, Poland.
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2
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Ferreira SGF, Sriramoju MK, Hsu STD, Faísca PFN, Machuqueiro M. Is There a Functional Role for the Knotted Topology in Protein UCH-L1? J Chem Inf Model 2024; 64:6827-6837. [PMID: 39045738 PMCID: PMC11388461 DOI: 10.1021/acs.jcim.4c00880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Knotted proteins are present in nature, but there is still an open issue regarding the existence of a universal role for these remarkable structures. To address this question, we used classical molecular dynamics (MD) simulations combined with in vitro experiments to investigate the role of the Gordian knot in the catalytic activity of UCH-L1. To create an unknotted form of UCH-L1, we modified its amino acid sequence by truncating several residues from its N-terminus. Remarkably, we find that deleting the first two N-terminal residues leads to a partial loss of enzyme activity with conservation of secondary structural content and knotted topological state. This happens because the integrity of the N-terminus is critical to ensure the correct alignment of the catalytic triad. However, the removal of five residues from the N-terminus, which significantly disrupts the native structure and the topological state, leads to a complete loss of enzymatic activity. Overall, our findings indicate that UCH-L1's catalytic activity depends critically on the integrity of the N-terminus and the secondary structure content, with the latter being strongly coupled with the knotted topological state.
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Affiliation(s)
- Sara G F Ferreira
- BioISI - Instituto de Biossistemas e Ciências Integrativas, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Manoj K Sriramoju
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Institute of Biochemical Sciences, National Taiwan University, Taipei 11529, Taiwan
| | - Patrícia F N Faísca
- BioISI - Instituto de Biossistemas e Ciências Integrativas, Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Miguel Machuqueiro
- BioISI - Instituto de Biossistemas e Ciências Integrativas, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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3
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Alves Silva JC, Barden Grillo I, A Urquiza-Carvalho G, Bruno Rocha G. Exploring the electronic structure of knotted proteins: the case of two ornithine transcarbamylase family. J Mol Model 2024; 30:265. [PMID: 39008190 DOI: 10.1007/s00894-024-06009-9] [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: 01/31/2024] [Accepted: 06/06/2024] [Indexed: 07/16/2024]
Abstract
CONTEXT Geometrical knots are rare structural arrangements in proteins in which the polypeptide chain ties itself into a knot, which is very intriguing due to the uncertainty of their impact on the protein properties. Presently, classical molecular dynamics is the most employed technique in the few studies found on this topic, so any information on how the presence of knots affects the reactivity and electronic properties of proteins is even scarcer. Using the electronic structure methods and quantum chemical descriptors analysis, we found that the same amino-acid residues in the knot core have statistically larger values for the unknotted protein, for both hard-hard and soft-soft interaction descriptors. In addition, we present a computationally feasible protocol, where we show it is possible to separate the contribution of the geometrical knot to the reactivity and other electronic structure properties. METHODS In order to investigate these systems, we used PRIMoRDiA, a new software developed by our research group, to explore the electronic structure of biological macromolecules. We evaluated several local quantum chemical descriptors to unveil relevant patterns potentially originating from the presence of the geometrical knot in two proteins, belonging to the ornithine transcarbamylase family. We compared several sampled structures from these two enzymes that are highly similar in both tertiary structure and function, but one of them has a knot whereas the other does not. The sampling was carried out through molecular dynamics simulations using ff14SB force field along 50 ns, and the semiempirical convergence was performed with PM7 Hamiltonian.
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Affiliation(s)
- José Cícero Alves Silva
- Department of Chemistry, Federal University of Paraíba, Cid. Universitária, João Pessoa, 58051-900, Paraíba, Brazil
| | - Igor Barden Grillo
- Department of Chemistry, Federal University of Paraíba, Cid. Universitária, João Pessoa, 58051-900, Paraíba, Brazil
| | - Gabriel A Urquiza-Carvalho
- Department of Chemistry, Federal University of Pernambuco, Cid. Universitária, Recife, 50670-901, Pernambuco, Brazil
| | - Gerd Bruno Rocha
- Department of Chemistry, Federal University of Paraíba, Cid. Universitária, João Pessoa, 58051-900, Paraíba, Brazil.
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4
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Sikora M, Klimentova E, Uchal D, Sramkova D, Perlinska AP, Nguyen ML, Korpacz M, Malinowska R, Nowakowski S, Rubach P, Simecek P, Sulkowska JI. Knot or not? Identifying unknotted proteins in knotted families with sequence-based Machine Learning model. Protein Sci 2024; 33:e4998. [PMID: 38888487 PMCID: PMC11184937 DOI: 10.1002/pro.4998] [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: 12/04/2023] [Revised: 03/14/2024] [Accepted: 04/09/2024] [Indexed: 06/20/2024]
Abstract
Knotted proteins, although scarce, are crucial structural components of certain protein families, and their roles continue to be a topic of intense research. Capitalizing on the vast collection of protein structure predictions offered by AlphaFold (AF), this study computationally examines the entire UniProt database to create a robust dataset of knotted and unknotted proteins. Utilizing this dataset, we develop a machine learning (ML) model capable of accurately predicting the presence of knots in protein structures solely from their amino acid sequences. We tested the model's capabilities on 100 proteins whose structures had not yet been predicted by AF and found agreement with our local prediction in 92% cases. From the point of view of structural biology, we found that all potentially knotted proteins predicted by AF can be classified only into 17 families. This allows us to discover the presence of unknotted proteins in families with a highly conserved knot. We found only three new protein families: UCH, DUF4253, and DUF2254, that contain both knotted and unknotted proteins, and demonstrate that deletions within the knot core could potentially account for the observed unknotted (trivial) topology. Finally, we have shown that in the majority of knotted families (11 out of 15), the knotted topology is strictly conserved in functional proteins with very low sequence similarity. We have conclusively demonstrated that proteins AF predicts as unknotted are structurally accurate in their unknotted configurations. However, these proteins often represent nonfunctional fragments, lacking significant portions of the knot core (amino acid sequence).
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Affiliation(s)
- Maciej Sikora
- Centre of New Technologies, University of WarsawWarsawPoland
- Faculty of Mathematics, Informatics and Mechanics, University of WarsawWarsawPoland
| | - Eva Klimentova
- Central European Institute of Technology, Masaryk UniversityBrnoCzech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrnoCzech Republic
| | - Dawid Uchal
- Centre of New Technologies, University of WarsawWarsawPoland
- Faculty of Physics, University of WarsawWarsawPoland
| | - Denisa Sramkova
- Central European Institute of Technology, Masaryk UniversityBrnoCzech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrnoCzech Republic
| | | | - Mai Lan Nguyen
- Centre of New Technologies, University of WarsawWarsawPoland
| | - Marta Korpacz
- Centre of New Technologies, University of WarsawWarsawPoland
- Faculty of Mathematics, Informatics and Mechanics, University of WarsawWarsawPoland
| | - Roksana Malinowska
- Centre of New Technologies, University of WarsawWarsawPoland
- Faculty of Mathematics, Informatics and Mechanics, University of WarsawWarsawPoland
| | - Szymon Nowakowski
- Faculty of Mathematics, Informatics and Mechanics, University of WarsawWarsawPoland
- Faculty of Physics, University of WarsawWarsawPoland
| | - Pawel Rubach
- Centre of New Technologies, University of WarsawWarsawPoland
- Warsaw School of EconomicsWarsawPoland
| | - Petr Simecek
- Central European Institute of Technology, Masaryk UniversityBrnoCzech Republic
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5
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Perlinska AP, Nguyen ML, Pilla SP, Staszor E, Lewandowska I, Bernat A, Purta E, Augustyniak R, Bujnicki JM, Sulkowska JI. Are there double knots in proteins? Prediction and in vitro verification based on TrmD-Tm1570 fusion from C. nitroreducens. Front Mol Biosci 2024; 10:1223830. [PMID: 38903539 PMCID: PMC11187310 DOI: 10.3389/fmolb.2023.1223830] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 10/04/2023] [Indexed: 06/22/2024] Open
Abstract
We have been aware of the existence of knotted proteins for over 30 years-but it is hard to predict what is the most complicated knot that can be formed in proteins. Here, we show new and the most complex knotted topologies recorded to date-double trefoil knots (31 #31). We found five domain arrangements (architectures) that result in a doubly knotted structure in almost a thousand proteins. The double knot topology is found in knotted membrane proteins from the CaCA family, that function as ion transporters, in the group of carbonic anhydrases that catalyze the hydration of carbon dioxide, and in the proteins from the SPOUT superfamily that gathers 31 knotted methyltransferases with the active site-forming knot. For each family, we predict the presence of a double knot using AlphaFold and RoseTTaFold structure prediction. In the case of the TrmD-Tm1570 protein, which is a member of SPOUT superfamily, we show that it folds in vitro and is biologically active. Our results show that this protein forms a homodimeric structure and retains the ability to modify tRNA, which is the function of the single-domain TrmD protein. However, how the protein folds and is degraded remains unknown.
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Affiliation(s)
| | - Mai Lan Nguyen
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Polish-Japanese Academy of Information Technology, Warsaw, Poland
| | - Smita P. Pilla
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Emilia Staszor
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | | | - Agata Bernat
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Elżbieta Purta
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | | | - Janusz M. Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
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6
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Niemyska W, Mukherjee S, Gren BA, Niewieczerzal S, Bujnicki JM, Sulkowska JI. Discovery of a trefoil knot in the RydC RNA: Challenging previous notions of RNA topology. J Mol Biol 2024; 436:168455. [PMID: 38272438 DOI: 10.1016/j.jmb.2024.168455] [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: 10/17/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
Knots are very common in polymers, including DNA and protein molecules. Yet, no genuine knot has been identified in natural RNA molecules to date. Upon re-examining experimentally determined RNA 3D structures, we discovered a trefoil knot 31, the most basic non-trivial knot, in the RydC RNA. This knotted RNA is a member of a small family of short bacterial RNAs, whose secondary structure is characterized by an H-type pseudoknot. Molecular dynamics simulations suggest a folding pathway of the RydC RNA that starts with a native twisted loop. Based on sequence analyses and computational RNA 3D structure predictions, we postulate that this trefoil knot is a conserved feature of all RydC-related RNAs. The first discovery of a knot in a natural RNA molecule introduces a novel perspective on RNA 3D structure formation and on fundamental research on the relationship between function and spatial structure of biopolymers.
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Affiliation(s)
- Wanda Niemyska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Banacha 2, 02-097 Warsaw, Poland.
| | - Sunandan Mukherjee
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Trojdena 4, 02-109 Warsaw, Poland
| | - Bartosz A Gren
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Szymon Niewieczerzal
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Trojdena 4, 02-109 Warsaw, Poland.
| | - Joanna I Sulkowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland.
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7
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Odeyemi I, Douglas TA, Igie NF, Hargrove JA, Hamilton G, Bradley BB, Thai C, Le B, Unjia M, Wicherts D, Ferneyhough Z, Pillai A, Koirala S, Hagge LM, Polara H, Trievel RC, Fick RJ, Stelling AL. An optimized purification protocol for enzymatically synthesized S-adenosyl-L-methionine (SAM) for applications in solution state infrared spectroscopic studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 309:123816. [PMID: 38198991 DOI: 10.1016/j.saa.2023.123816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 11/07/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024]
Abstract
S-adenosyl-L-methionine (SAM) is an abundant biomolecule used by methyltransferases to regulate a wide range of essential cellular processes such as gene expression, cell signaling, protein functions, and metabolism. Despite considerable effort, there remain many specificity challenges associated with designing small molecule inhibitors for methyltransferases, most of which exhibit off-target effects. Interestingly, NMR evidence suggests that SAM undergoes conformeric exchange between several states when free in solution. Infrared spectroscopy can detect different conformers of molecules if present in appreciable populations. When SAM is noncovalently bound within enzyme active sites, the nature and the number of different conformations of the molecule are likely to be altered from when it is free in solution. If there are unique structures or different numbers of conformers between different methyltransferase active sites, solution-state information may provide promising structural leads to increase inhibitor specificity for a particular methyltransferase. Toward this goal, frequencies measured in SAM's infrared spectra must be assigned to the motions of specific atoms via isotope incorporation at discrete positions. The incorporation of isotopes into SAM's structure can be accomplished via an established enzymatic synthesis using isotopically labeled precursors. However, published protocols produced an intense and highly variable IR signal which overlapped with many of the signals from SAM rendering comparison between isotopes challenging. We observed this intense absorption to be from co-purifying salts and the SAM counterion, producing a strong, broad signal at 1100 cm-1. Here, we report a revised SAM purification protocol that mitigates the contaminating salts and present the first IR spectra of isotopically labeled CD3-SAM. These results provide a foundation for isotopic labeling experiments of SAM that will define which atoms participate in individual molecular vibrations, as a means to detect specific molecular conformations.
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Affiliation(s)
- Isaiah Odeyemi
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Teri A Douglas
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Nosakhare F Igie
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - James A Hargrove
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Grace Hamilton
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Brianna B Bradley
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Cathy Thai
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Brendan Le
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Maitri Unjia
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Dylan Wicherts
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Zackery Ferneyhough
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Anjali Pillai
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Shailendra Koirala
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Laurel M Hagge
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Himanshu Polara
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Raymond C Trievel
- University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, 48109, MI, USA
| | - Robert J Fick
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA
| | - Allison L Stelling
- The University of Texas at Dallas, 800 W. Campbell Rd., Richardson, 75080, TX, USA.
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8
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Zayats V, Sikora M, Perlinska AP, Stasiulewicz A, Gren BA, Sulkowska JI. Conservation of knotted and slipknotted topology in transmembrane transporters. Biophys J 2023; 122:4528-4541. [PMID: 37919904 PMCID: PMC10719070 DOI: 10.1016/j.bpj.2023.10.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 08/25/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023] Open
Abstract
The existence of nontrivial topology is well accepted in globular proteins but not in membrane proteins. Our comprehensive topological analysis of the Protein Data Bank structures reveals 18 families of transmembrane proteins with nontrivial topology, showing that they constitute a significant number of membrane proteins. Moreover, we found that they comprise one of the largest groups of secondary active transporters. We classified them based on their knotted fingerprint into four groups: three slipknotted and one knotted. Unexpectedly, we found that the same protein can possess two distinct slipknot motifs that correspond to its outward- and inward-open conformational state. Based on the analysis of structures and knotted fingerprints, we show that slipknot topology is directly involved in the conformational transition and substrate transfer. Therefore, entanglement can be used to classify proteins and to find their structure-function relationship. Furthermore, based on the topological analysis of the transmembrane protein structures predicted by AlphaFold, we identified new potentially slipknotted protein families.
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Affiliation(s)
- Vasilina Zayats
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Maciej Sikora
- Centre of New Technologies, University of Warsaw, Warsaw, Poland; Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Warsaw, Poland
| | | | - Adam Stasiulewicz
- Centre of New Technologies, University of Warsaw, Warsaw, Poland; Department of Drug Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland
| | - Bartosz A Gren
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
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9
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Jedrzejewski M, Belza B, Lewandowska I, Sadlej M, Perlinska AP, Augustyniak R, Christian T, Hou YM, Kalek M, Sulkowska JI. Nucleolar Essential Protein 1 (Nep1): Elucidation of enzymatic catalysis mechanism by molecular dynamics simulation and quantum mechanics study. Comput Struct Biotechnol J 2023; 21:3999-4008. [PMID: 37649713 PMCID: PMC10462857 DOI: 10.1016/j.csbj.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 09/01/2023] Open
Abstract
The Nep1 protein is essential for the formation of eukaryotic and archaeal small ribosomal subunits, and it catalyzes the site-directed SAM-dependent methylation of pseudouridine (Ψ) during pre-rRNA processing. It possesses a non-trivial topology, namely, a 31 knot in the active site. Here, we address the issue of seemingly unfeasible deprotonation of Ψ in Nep1 active site by a distant aspartate residue (D101 in S. cerevisiae), using a combination of bioinformatics, computational, and experimental methods. We identified a conserved hydroxyl-containing amino acid (S233 in S. cerevisiae, T198 in A. fulgidus) that may act as a proton-transfer mediator. Molecular dynamics simulations, based on the crystal structure of S. cerevisiae, and on a complex generated by molecular docking in A. fulgidus, confirmed that this amino acid can shuttle protons, however, a water molecule in the active site may also serve this role. Quantum-chemical calculations based on density functional theory and the cluster approach showed that the water-mediated pathway is the most favorable for catalysis. Experimental kinetic and mutational studies reinforce the requirement for the aspartate D101, but not S233. These findings provide insight into the catalytic mechanisms underlying proton transfer over extended distances and comprehensively elucidate the mode of action of Nep1.
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Affiliation(s)
- Mateusz Jedrzejewski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Barbara Belza
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Iwona Lewandowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Marta Sadlej
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Agata P. Perlinska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Rafal Augustyniak
- Department of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093, Warsaw, Poland
| | - Thomas Christian
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 4201 Henry Ave, Philadelphia, PA 19144, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 4201 Henry Ave, Philadelphia, PA 19144, USA
| | - Marcin Kalek
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Joanna I. Sulkowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
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10
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Investigation of the structural dynamics of a knotted protein and its unknotted analog using molecular dynamics. J Mol Model 2022; 28:108. [PMID: 35357594 DOI: 10.1007/s00894-022-05094-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/12/2022] [Indexed: 10/18/2022]
Abstract
The role of knots in proteins remains elusive. Some studies suggest an impact on stability; the difficulty in comparing systems to assess this effect, however, has been a significant challenge. In this study, we produced and analyzed molecular dynamic trajectories considering three different temperatures of two variants of ornithine transcarbamylase (OTC), only one of which has a 31 knot, in order to evaluate the relative stability of the two molecules. RMSD showed equilibrated structures for the produced trajectories, and RMSF showed subtle differences in flexibility. In the knot moiety, the knotted protein did not show a great deal of fluctuation at any temperature. For the unknotted protein, the residue GLY243 showed a high fluctuation in the corresponding moiety. The fraction of native contacts (Q) showed a similar profile at all temperatures, with the greatest decrease by 436 K. The investigation of conformational behavior with principal component analysis (PCA) and dynamic cross-correlation map (DCCM) showed that knotted protein is less likely to undergo changes in its conformation under the conditions employed compared to unknotted. PCA data showed that the unknotted protein had greater dispersion in its conformations, which suggests that it has a greater capacity for conformation transitions in response to thermal changes. DCCM graphs comparing the 310 K and 436 K temperatures showed that the knotted protein had less change in its correlation and anti-correlation movements, indicating stability compared to the unknotted.
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11
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Wang J, Peng X. In silico method for identifying the key residues in a knotted protein: with MJ0366 as an example. Phys Chem Chem Phys 2022; 24:27495-27504. [DOI: 10.1039/d2cp03589h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A simple in silico method for predicting the key residues for knotting and unknotting a knotted protein is put forward, with the residues ranked by the relevance to knotting and unknotting in the annealing molecular dynamics simulations.
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Affiliation(s)
- Jianmei Wang
- Center for Quantum Technology Research, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Xubiao Peng
- Center for Quantum Technology Research, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
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12
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Slipknotted and unknotted monovalent cation-proton antiporters evolved from a common ancestor. PLoS Comput Biol 2021; 17:e1009502. [PMID: 34648493 PMCID: PMC8562792 DOI: 10.1371/journal.pcbi.1009502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/02/2021] [Accepted: 09/28/2021] [Indexed: 11/20/2022] Open
Abstract
While the slipknot topology in proteins has been known for over a decade, its evolutionary origin is still a mystery. We have identified a previously overlooked slipknot motif in a family of two-domain membrane transporters. Moreover, we found that these proteins are homologous to several families of unknotted membrane proteins. This allows us to directly investigate the evolution of the slipknot motif. Based on our comprehensive analysis of 17 distantly related protein families, we have found that slipknotted and unknotted proteins share a common structural motif. Furthermore, this motif is conserved on the sequential level as well. Our results suggest that, regardless of topology, the proteins we studied evolved from a common unknotted ancestor single domain protein. Our phylogenetic analysis suggests the presence of at least seven parallel evolutionary scenarios that led to the current diversity of proteins in question. The tools we have developed in the process can now be used to investigate the evolution of other repeated-domain proteins. In proteins with the slipknot topology, the polypeptide chain forms a slipknot—a structure that is not necessarily manifest to a naked eye, but it can be detected using mathematical methods. Slipknots are conserved motifs often found at catalytic sites and are directly involved in molecular transport. Although the first proteins with slipknots were found in 2007, many questions remain unanswered, e.g. how these proteins appeared, or whether the slipknotted proteins evolved from unknotted ones or vice versa. Here we provide the first analysis of homologous slipknotted and unknotted transmembrane proteins in order to elucidate their evolutionary relationship. We show that two-domain slipknotted and unknotted membrane transporters share the same one-domain unknotted protein as an ancestor. The ancestor gene duplicated and underwent various diversification and fusion events during the evolution, which have led to the appearance of a large superfamily of secondary active transporters. The slipknot motif seems to have been created by chance after a fusion of two single domain genes. Therefore, we show here that the slipknotted transporter evolved from an unknotted one-domain protein and that there are at least seven different evolutionary scenarios that gave rise to this large superfamily of transporters.
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Qiao J, Zhao C. Therapeutic effect of adenosylmethionine on viral hepatitis and related factors inducing diseas. Am J Transl Res 2021; 13:9485-9494. [PMID: 34540070 PMCID: PMC8430085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 02/01/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVE To analyze the therapeutic efficacy of adenosylmethionine on viral hepatitis and the related factors inducing disease. METHODS From May 2018 to April 2019, 137 patients with viral hepatitis who received treatment in our hospital were selected and assigned to two groups according to different treatment methods. In the control group (CG), 61 cases were treated with routine liver protection and enzyme reduction. In the research group, 76 cases were treated with adenosylmethionine on the basis of the CG. After therapy, the total response rate was analyzed in both groups, and the adverse reactions were observed during the treatment. The liver function indexes [albumin (ALB), alanine aminotransferase (ALT), glutamic acid transaminase (AST) and total bilirubin (TBIL)], liver fiber indicators [hyaluronic acid (HA), laminin (LN), type III procollagen (PCIII), type IV collagen (IV-C)], inflammatory factors [interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] were compared in both groups before and after therapy. ELISA was applied to detect inflammatory factors in both groups before and after treatment. Logistic analysis was applied to analyze the independent risk factors affecting the curative effect of patients with viral hepatitis. RESULTS After therapy, the total response rate of patients in RG was obviously higher than that in CG; The total incidence of adverse effects in RG was obviously lower than that in CG; The improvement of liver function indexes and liver fiber indicators in RG was better than that in CG; The expression of inflammatory factors in RG was obviously lower than that in CG. Logistic analysis revealed that patients' age (>40 years old), drinking history, family history, low improvement of hepatic function and hepatic fibrosis, high level of inflammatory cytokines and routine treatment were independent prognostic factors affecting patients with viral hepatitis. CONCLUSION Adenosylmethionine intervention can promote disease recovery, reduce inflammation level and improve liver function damage for patients with viral hepatitis.
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Affiliation(s)
- Jinggui Qiao
- Department of Gastroenterology, Xi'an Gaoxing Hospital Xi'an 710000, Shaanxi Province, China
| | - Congya Zhao
- Department of Gastroenterology, Xi'an Gaoxing Hospital Xi'an 710000, Shaanxi Province, China
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Perlinska AP, Kalek M, Christian T, Hou YM, Sulkowska JI. Mg 2+-Dependent Methyl Transfer by a Knotted Protein: A Molecular Dynamics Simulation and Quantum Mechanics Study. ACS Catal 2020; 10:8058-8068. [PMID: 32904895 PMCID: PMC7462349 DOI: 10.1021/acscatal.0c00059] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 06/18/2020] [Indexed: 11/27/2022]
Abstract
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Mg2+ is required for the catalytic activity of TrmD,
a bacteria-specific methyltransferase that is made up of a protein
topological knot-fold, to synthesize methylated m1G37-tRNA
to support life. However, neither the location of Mg2+ in
the structure of TrmD nor its role in the catalytic mechanism is known.
Using molecular dynamics (MD) simulations, we identify a plausible
Mg2+ binding pocket within the active site of the enzyme,
wherein the ion is coordinated by two aspartates and a glutamate.
In this position, Mg2+ additionally interacts with the
carboxylate of a methyl donor cofactor S-adenosylmethionine (SAM).
The computational results are validated by experimental mutation studies,
which demonstrate the importance of the Mg2+-binding residues
for the catalytic activity. The presence of Mg2+ in the
binding pocket induces SAM to adopt a unique bent shape required for
the methyl transfer activity and causes a structural reorganization
of the active site. Quantum mechanical calculations show that the
methyl transfer is energetically feasible only when Mg2+ is bound in the position revealed by the MD simulations, demonstrating
that its function is to align the active site residues within the
topological knot-fold in a geometry optimal for catalysis. The obtained
insights provide the opportunity for developing a strategy of antibacterial
drug discovery based on targeting of Mg2+-binding to TrmD.
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Affiliation(s)
- Agata P. Perlinska
- Centre of New Technologies, University of Warsaw, Warsaw 02-097, Poland
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw 02-097, Poland
| | - Marcin Kalek
- Centre of New Technologies, University of Warsaw, Warsaw 02-097, Poland
| | - Thomas Christian
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - Joanna I. Sulkowska
- Centre of New Technologies, University of Warsaw, Warsaw 02-097, Poland
- Faculty of Chemistry, University of Warsaw, Warsaw 02-097, Poland
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