1
|
Pokorná P, Mlýnský V, Bussi G, Šponer J, Stadlbauer P. Molecular dynamics simulations reveal the parallel stranded d(GGGA) 3GGG DNA quadruplex folds via multiple paths from a coil-like ensemble. Int J Biol Macromol 2024; 261:129712. [PMID: 38286387 DOI: 10.1016/j.ijbiomac.2024.129712] [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: 09/21/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/31/2024]
Abstract
G-quadruplexes (G4s) are non-canonical nucleic acid structures that fold through complex processes. Characterization of the G4 folding landscape may help to elucidate biological roles of G4s but is challenging both experimentally and computationally. Here, we achieved complete folding of a three-quartet parallel DNA G4 with (GGGA)3GGG sequence using all-atom explicit-solvent enhanced-sampling molecular dynamics (MD) simulations. The simulations suggested early formation of guanine stacks in the G-tracts, which behave as semi-rigid blocks in the folding process. The folding continues via the formation of a collapsed compact coil-like ensemble. Structuring of the G4 from the coil then proceeds via various cross-like, hairpin, slip-stranded and two-quartet ensembles and can bypass the G-triplex structure. Folding of the parallel G4 does not appear to involve any salient intermediates and is a multi-pathway process. We also carried out an extended set of simulations of parallel G-hairpins. While parallel G-hairpins are extremely unstable when isolated, they are more stable inside the coil structure. On the methodology side, we show that the AMBER DNA force field predicts the folded G4 to be less stable than the unfolded ensemble, uncovering substantial force-field issues. Overall, we provide unique atomistic insights into the folding landscape of parallel-stranded G4 but also reveal limitations of current state-of-the-art MD techniques.
Collapse
Affiliation(s)
- Pavlína Pokorná
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, Trieste 34136, Italy
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic.
| |
Collapse
|
2
|
Stadlbauer P, Mlýnský V, Krepl M, Šponer J. Complexity of Guanine Quadruplex Unfolding Pathways Revealed by Atomistic Pulling Simulations. J Chem Inf Model 2023; 63:4716-4731. [PMID: 37458574 PMCID: PMC10428220 DOI: 10.1021/acs.jcim.3c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Indexed: 08/15/2023]
Abstract
Guanine quadruplexes (GQs) are non-canonical nucleic acid structures involved in many biological processes. GQs formed in single-stranded regions often need to be unwound by cellular machinery, so their mechanochemical properties are important. Here, we performed steered molecular dynamics simulations of human telomeric GQs to study their unfolding. We examined four pulling regimes, including a very slow setup with pulling velocity and force load accessible to high-speed atomic force microscopy. We identified multiple factors affecting the unfolding mechanism, i.e.,: (i) the more the direction of force was perpendicular to the GQ channel axis (determined by GQ topology), the more the base unzipping mechanism happened, (ii) the more parallel the direction of force was, GQ opening and cross-like GQs were more likely to occur, (iii) strand slippage mechanism was possible for GQs with an all-anti pattern in a strand, and (iv) slower pulling velocity led to richer structural dynamics with sampling of more intermediates and partial refolding events. We also identified that a GQ may eventually unfold after a force drop under forces smaller than those that the GQ withstood before the drop. Finally, we found out that different unfolding intermediates could have very similar chain end-to-end distances, which reveals some limitations of structural interpretations of single-molecule spectroscopic data.
Collapse
Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| |
Collapse
|
3
|
Panczyk T, Nieszporek K, Wolski P. Stability and Existence of Noncanonical I-motif DNA Structures in Computer Simulations Based on Atomistic and Coarse-Grained Force Fields. Molecules 2022; 27:molecules27154915. [PMID: 35956863 PMCID: PMC9370271 DOI: 10.3390/molecules27154915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/13/2022] [Accepted: 07/26/2022] [Indexed: 11/24/2022] Open
Abstract
Cytosine-rich DNA sequences are able to fold into noncanonical structures, in which semi-protonated cytosine pairs develop extra hydrogen bonds, and these bonds are responsible for the overall stability of a structure called the i-motif. The i-motif can be formed in many regions of the genome, but the most representative is the telomeric region in which the CCCTAA sequences are repeated thousands of times. The ability to reverse folding/unfolding in response to pH change makes the above sequence and i-motif very promising components of nanomachines, extended DNA structures, and drug carriers. Molecular dynamics analysis of such structures is highly beneficial due to direct insights into the microscopic structure of the considered systems. We show that Amber force fields for DNA predict the stability of the i-motif over a long timescale; however, these force fields are not able to predict folding of the cytosine-rich sequences into the i-motif. The reason is the kinetic partitioning of the folding process, which makes the transitions between various intermediates too time-consuming in atomistic force field representation. Application of coarse-grained force fields usually highly accelerates complex structural transitions. We, however, found that three of the most popular coarse-grained force fields for DNA (oxDNA, 3SPN, and Martini) were not able to predict the stability of the i-motif structure. Obviously, they were not able to accelerate the folding of unfolded states into an i-motif. This observation must be strongly highlighted, and the need to develop suitable extensions of coarse-grained force fields for DNA is pointed out. However, it will take a great deal of effort to successfully solve these problems.
Collapse
Affiliation(s)
- Tomasz Panczyk
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland;
- Correspondence:
| | - Krzysztof Nieszporek
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University in Lublin pl. Maria Curie-Sklodowska 3, 20031 Lublin, Poland;
| | - Pawel Wolski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland;
| |
Collapse
|
4
|
Bian Y, Song F, Zhang J, Yu J, Wang J, Wang W. Insights into the Kinetic Partitioning Folding Dynamics of the Human Telomeric G-Quadruplex from Molecular Simulations and Machine Learning. J Chem Theory Comput 2020; 16:5936-5947. [PMID: 32794754 DOI: 10.1021/acs.jctc.0c00340] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human telomeric DNA G-quadruplex follows a kinetic partitioning folding mechanism. The underlying folding landscape potentially has many minima separated by high free-energy barriers. However, using current theoretical models to characterize this complex folding landscape has remained a challenging problem. In this study, by developing a hybrid atomistic structure-based model that merges structural information on the hybrid-1, hybrid-2, and chair-type G-quadruplex topologies, we investigated a kinetic partitioning folding process of human telomeric DNA involving three native folds. The model was validated as it reproduced the experimental observation that the hybrid-1 conformation is the major fold and the hybrid-2 conformation is kinetically more accessible. A three-step mechanism was revealed for the formation of the hybrid-1 conformation, while a two-step mechanism was demonstrated for the formation of hybrid-2 and chair-type conformations. Likewise, a class of state in which structures adopted inappropriate combinations of syn/anti guanine nucleotides was found to greatly slow down the folding process. In addition, by employing the XGBoost machine learning algorithm, three interatom distances and six dihedral angles were identified as essential internal coordinates to represent the low-dimensional folding landscape. The strategy of coupling the multibasin model and the machine learning algorithm may be useful to investigate the conformational dynamics of other multistate biomolecules.
Collapse
Affiliation(s)
- Yunqiang Bian
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.,National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Feng Song
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Jian Zhang
- National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jiafeng Yu
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Jihua Wang
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Wei Wang
- National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| |
Collapse
|
5
|
Molecular dynamics simulations of G-quadruplexes: The basic principles and their application to folding and ligand binding. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2020. [DOI: 10.1016/bs.armc.2020.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
6
|
Stadlbauer P, Kührová P, Vicherek L, Banáš P, Otyepka M, Trantírek L, Šponer J. Parallel G-triplexes and G-hairpins as potential transitory ensembles in the folding of parallel-stranded DNA G-Quadruplexes. Nucleic Acids Res 2019; 47:7276-7293. [PMID: 31318975 PMCID: PMC6698752 DOI: 10.1093/nar/gkz610] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/26/2019] [Accepted: 07/03/2019] [Indexed: 12/29/2022] Open
Abstract
Guanine quadruplexes (G4s) are non-canonical nucleic acids structures common in important genomic regions. Parallel-stranded G4 folds are the most abundant, but their folding mechanism is not fully understood. Recent research highlighted that G4 DNA molecules fold via kinetic partitioning mechanism dominated by competition amongst diverse long-living G4 folds. The role of other intermediate species such as parallel G-triplexes and G-hairpins in the folding process has been a matter of debate. Here, we use standard and enhanced-sampling molecular dynamics simulations (total length of ∼0.9 ms) to study these potential folding intermediates. We suggest that parallel G-triplex per se is rather an unstable species that is in local equilibrium with a broad ensemble of triplex-like structures. The equilibrium is shifted to well-structured G-triplex by stacked aromatic ligand and to a lesser extent by flanking duplexes or nucleotides. Next, we study propeller loop formation in GGGAGGGAGGG, GGGAGGG and GGGTTAGGG sequences. We identify multiple folding pathways from different unfolded and misfolded structures leading towards an ensemble of intermediates called cross-like structures (cross-hairpins), thus providing atomistic level of description of the single-molecule folding events. In summary, the parallel G-triplex is a possible, but not mandatory short-living (transitory) intermediate in the folding of parallel-stranded G4.
Collapse
Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, 771 46 Olomouc, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacky University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Lukáš Vicherek
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Pavel Banáš
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacky University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacky University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Lukáš Trantírek
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, 612 65 Brno, Czech Republic.,Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, 771 46 Olomouc, Czech Republic.,Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| |
Collapse
|
7
|
Panczyk T, Wojton P, Wolski P. Mechanism of unfolding and relative stabilities of G-quadruplex and I-motif noncanonical DNA structures analyzed in biased molecular dynamics simulations. Biophys Chem 2019; 250:106173. [DOI: 10.1016/j.bpc.2019.106173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/01/2022]
|
8
|
Nussinov R, Tsai CJ, Shehu A, Jang H. Computational Structural Biology: Successes, Future Directions, and Challenges. Molecules 2019; 24:molecules24030637. [PMID: 30759724 PMCID: PMC6384756 DOI: 10.3390/molecules24030637] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/05/2019] [Accepted: 02/10/2019] [Indexed: 02/06/2023] Open
Abstract
Computational biology has made powerful advances. Among these, trends in human health have been uncovered through heterogeneous 'big data' integration, and disease-associated genes were identified and classified. Along a different front, the dynamic organization of chromatin is being elucidated to gain insight into the fundamental question of genome regulation. Powerful conformational sampling methods have also been developed to yield a detailed molecular view of cellular processes. when combining these methods with the advancements in the modeling of supramolecular assemblies, including those at the membrane, we are finally able to get a glimpse into how cells' actions are regulated. Perhaps most intriguingly, a major thrust is on to decipher the mystery of how the brain is coded. Here, we aim to provide a broad, yet concise, sketch of modern aspects of computational biology, with a special focus on computational structural biology. We attempt to forecast the areas that computational structural biology will embrace in the future and the challenges that it may face. We skirt details, highlight successes, note failures, and map directions.
Collapse
Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
| | - Amarda Shehu
- Departments of Computer Science, Department of Bioengineering, and School of Systems Biology, George Mason University, Fairfax, VA 22030, USA.
| | - Hyunbum Jang
- Computational Structural Biology Section, Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
| |
Collapse
|
9
|
Wolski P, Nieszporek K, Panczyk T. G-Quadruplex and I-Motif Structures within the Telomeric DNA Duplex. A Molecular Dynamics Analysis of Protonation States as Factors Affecting Their Stability. J Phys Chem B 2018; 123:468-479. [DOI: 10.1021/acs.jpcb.8b11547] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pawel Wolski
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland
| | - Krzysztof Nieszporek
- Department of Chemistry, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 3, 20031 Lublin, Poland
| | - Tomasz Panczyk
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland
| |
Collapse
|
10
|
Pal S, Paul S. Conformational deviation of Thrombin binding G-quadruplex aptamer (TBA) in presence of divalent cation Sr 2+: A classical molecular dynamics simulation study. Int J Biol Macromol 2018; 121:350-363. [PMID: 30308284 DOI: 10.1016/j.ijbiomac.2018.09.102] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 08/27/2018] [Accepted: 09/17/2018] [Indexed: 11/28/2022]
Abstract
Thrombin binding TBA-G-quadruplex aptamer (TBA) plays a major role in blood coagulation cascade. The 15-mer TBA sequence tends to form four-stranded TBA-G-quadruplex structure. In this research work, a series of explicit solvent classical MD simulations of the TBA is carried out using different salt (SrCl2) concentrations (0, 50, 100 and 200 mM). Here we have also testified the effect of salt concentration of divalent cation Sr2+ on the conformational change of quadruplex DNA. The structural deviations, fluctuations, torsional angles and the affinity of the ion are explored at different salt concentrations. It is found that the conformation of TBA-G-quadruplex at 0 mM and 50 mM salt concentrations, is very much different than the other salt concentrations (100 mM and 200 mM). Also observed are as follows: (i) no exchange of Sr2+ ion between inside and outside of the channel, (ii) an enhancement in the Sr2+ ion density around the phosphate region of the loop residues as salt concentration increases and (iii) the stacking of T3 and T4 residues of loop-1 that appears up to 50 mM concentration, vanishes as the salt concentration is increased further.
Collapse
Affiliation(s)
- Saikat Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India.
| |
Collapse
|