1
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Sangeeta, Mishra SK, Bhattacherjee A. Role of Shape Deformation of DNA-Binding Sites in Regulating the Efficiency and Specificity in Their Recognition by DNA-Binding Proteins. JACS AU 2024; 4:2640-2655. [PMID: 39055163 PMCID: PMC11267559 DOI: 10.1021/jacsau.4c00393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 07/27/2024]
Abstract
Accurate transcription of genetic information is crucial, involving precise recognition of the binding motifs by DNA-binding proteins. While some proteins rely on short-range hydrophobic and hydrogen bonding interactions at binding sites, others employ a DNA shape readout mechanism for specific recognition. In this mechanism, variations in DNA shape at the binding motif resulted from either inherent flexibility or binding of proteins at adjacent sites are sensed and capitalized by the searching proteins to locate them specifically. Through extensive computer simulations, we investigate both scenarios to uncover the underlying mechanism and origin of specificity in the DNA shape readout mechanism. Our findings reveal that deformation in shape at the binding motif creates an entropy funnel, allowing information about altered shapes to manifest as fluctuations in minor groove widths. This signal enhances the efficiency of nonspecific search of nearby proteins by directing their movement toward the binding site, primarily driven by a gain in entropy. We propose this as a generic mechanism for DNA shape readout, where specificity arises from the alignment between the molecular frustration of the searching protein and the ruggedness of the entropic funnel governed by molecular features of the protein and arrangement of the DNA bases at the binding site, respectively.
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Affiliation(s)
- Sangeeta
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sujeet Kumar Mishra
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Arnab Bhattacherjee
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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2
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Mathur D, Thakur M, Díaz SA, Susumu K, Stewart MH, Oh E, Walper SA, Medintz IL. Hybrid Nucleic Acid-Quantum Dot Assemblies as Multiplexed Reporter Platforms for Cell-Free Transcription Translation-Based Biosensors. ACS Synth Biol 2022; 11:4089-4102. [PMID: 36441919 PMCID: PMC9829448 DOI: 10.1021/acssynbio.2c00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-free synthetic biology has emerged as a valuable tool for the development of rapid, portable biosensors that can be readily transported in the freeze-dried form to the point of need eliminating cold chain requirements. One of the challenges associated with cell-free sensors is the ability to simultaneously detect multiple analytes within a single reaction due to the availability of a limited set of fluorescent and colorimetric reporters. To potentially provide multiplexing capabilities to cell-free biosensors, we designed a modular semiconductor quantum dot (QD)-based reporter platform that is plugged in downstream of the transcription-translation functionality in the cell-free reaction and which converts enzymatic activity in the reaction into distinct optical signals. We demonstrate proof of concept by converting restriction enzyme activity, utilized as our prototypical sensing output, into optical changes across several distinct spectral output channels that all use a common excitation wavelength. These hybrid Förster resonance energy transfer (FRET)-based QD peptide PNA-DNA-Dye reporters (QD-PDDs) are completely self-assembled and consist of differentially emissive QD donors paired to a dye-acceptor displayed on a unique DNA encoding a given enzyme's cleavage site. Three QD-based PDDs, independently activated by the enzymes BamHI, EcoRI, and NcoI, were prototyped in mixed enzyme assays where all three demonstrated the ability to convert enzymatic activity into fluorescent output. Simultaneous monitoring of each of the three paired QD-donor dye-acceptor spectral channels in cell-free biosensing reactions supplemented with added linear genes encoding each enzyme confirmed robust multiplexing capabilities for at least two enzymes when co-expressed. The modular QD-PDDs are easily adapted to respond to other restriction enzymes or even proteases if desired.
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Affiliation(s)
| | | | - Sebastián A. Díaz
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Kimihiro Susumu
- Jacobs Corporation, Hanover, Maryland 21076, United States; Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Michael H. Stewart
- Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Eunkeu Oh
- Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Scott A. Walper
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
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3
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Adedeji Olulana AF, Choi D, Inverso V, Redhu SK, Vidonis M, Crevatin L, Nicholson AW, Castronovo M. Noncanonical DNA Cleavage by BamHI Endonuclease in Laterally Confined DNA Monolayers Is a Step Function of DNA Density and Sequence. Molecules 2022; 27:5262. [PMID: 36014501 PMCID: PMC9416302 DOI: 10.3390/molecules27165262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/04/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
Cleavage of DNA at noncanonical recognition sequences by restriction endonucleases (star activity) in bulk solution can be promoted by global experimental parameters, including enzyme or substrate concentration, temperature, pH, or buffer composition. To study the effect of nanoscale confinement on the noncanonical behaviour of BamHI, which cleaves a single unique sequence of 6 bp, we used AFM nanografting to generate laterally confined DNA monolayers (LCDM) at different densities, either in the form of small patches, several microns in width, or complete monolayers of thiol-modified DNA on a gold surface. We focused on two 44-bp DNAs, each containing a noncanonical BamHI site differing by 2 bp from the cognate recognition sequence. Topographic AFM imaging was used to monitor end-point reactions by measuring the decrease in the LCDM height with respect to the surrounding reference surface. At low DNA densities, BamHI efficiently cleaves only its cognate sequence while at intermediate DNA densities, noncanonical sequence cleavage occurs, and can be controlled in a stepwise (on/off) fashion by varying the DNA density and restriction site sequence. This study shows that endonuclease action on noncanonical sites in confined nanoarchitectures can be modulated by varying local physical parameters, independent of global chemical parameters.
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Affiliation(s)
- Abimbola F. Adedeji Olulana
- Department of Physics, PhD School in Nanotechnology, University of Trieste, 34127 Trieste, Italy
- Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
- Regional Centre for Rare Diseases, University Hospital Udine, 33100 Udine, Italy
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
| | - Dianne Choi
- Department of Biology, Temple University, Philadelphia, PA 19122-6078, USA
| | - Vincent Inverso
- Department of Biology, Temple University, Philadelphia, PA 19122-6078, USA
| | - Shiv K. Redhu
- Department of Biology, Temple University, Philadelphia, PA 19122-6078, USA
| | - Marco Vidonis
- Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
- Department of Chemistry, University of Rome “Tor Vergata”, 00133 Rome, Italy
| | - Luca Crevatin
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Allen W. Nicholson
- Department of Biology, Temple University, Philadelphia, PA 19122-6078, USA
| | - Matteo Castronovo
- Department of Physics, PhD School in Nanotechnology, University of Trieste, 34127 Trieste, Italy
- Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
- Regional Centre for Rare Diseases, University Hospital Udine, 33100 Udine, Italy
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
- Department of Biology, Temple University, Philadelphia, PA 19122-6078, USA
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4
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Restriction endonuclease T.Smu451I with new cleavage specificity-neoschizomer of T.AsuI. Folia Microbiol (Praha) 2021; 66:651-657. [PMID: 33950513 DOI: 10.1007/s12223-021-00874-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2021] [Indexed: 10/21/2022]
Abstract
A specific type II restriction endonuclease T.Smu451I has been purified to electrophoretic homogeneity from the frozen cells of soil bacterium Sphingobacterium multivorum 451 (formerly Flavobacterium multivorum 451), using ultrasonic grinding, nucleic acid removal by streptomycin sulfate, protein precipitation by ammonium sulfate and phosphocellulose P-11, DEAE-Cellulose DE-52, Hepharin-Sepharose CL-6B chromatography, and elucidated several characteristics of T.Smu451I. The molecular weight of the enzyme determined by gel filtration and SDS-polyacrylamide gel electrophoresis was calculated to be 45,000 ± 2000 D (dimer) and 23,000 ± 1000 D (monomer), respectively. The isoelectric point (pI) of T.Smu451I is 5.4. T.Smu451I recognizes pentanucleotide palindromic sequences 5'-GGNC↓C-3' and cleaves between C and C in position shown by arrow to produce 3'-cohesive terminus of trinucleotide. Therefore, T.Smu451I is a neoschizomer of T.AsuI.
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5
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Singh RK, Mukherjee A. Molecular Mechanism of the Intercalation of the SOX-4 Protein into DNA Inducing Bends and Kinks. J Phys Chem B 2021; 125:3752-3762. [PMID: 33848164 DOI: 10.1021/acs.jpcb.0c11496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
DNA-protein interactions regulate several biophysical functions, yet the mechanism of only a few is investigated in molecular detail. An important example is the intercalation of transcription factor proteins into DNA that produce bent and kinked DNA. Here, we have studied the molecular mechanism of the intercalation of a transcription factor SOX4 into DNA with a goal to understand the sequence of molecular events that precede the bending and kinking of the DNA. Our long well-tempered metadynamics and molecular dynamics (MD) simulations show that the protein primarily binds to the backbone of DNA and rotates around it to form an intercalative native state. We show that although there are multiple pathways for intercalation, the deintercalation pathway matches with the most probable intercalation pathway. In both cases, bending and kinking happen simultaneously, driven by the onset of the intercalation of the amino acid.
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Affiliation(s)
- Reman Kumar Singh
- Department of Chemistry, Indian Institute of Science Education and Research, Pune 411008, India
| | - Arnab Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research, Pune 411008, India
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6
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Miyazono KI, Wang D, Ito T, Tanokura M. Crystal structure and DNA cleavage mechanism of the restriction DNA glycosylase R.CcoLI from Campylobacter coli. Sci Rep 2021; 11:859. [PMID: 33441677 PMCID: PMC7806768 DOI: 10.1038/s41598-020-79537-y] [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: 07/16/2020] [Accepted: 12/09/2020] [Indexed: 11/09/2022] Open
Abstract
While most restriction enzymes catalyze the hydrolysis of phosphodiester bonds at specific nucleotide sequences in DNA, restriction enzymes of the HALFPIPE superfamily cleave N-glycosidic bonds, similar to DNA glycosylases. Apurinic/apyrimidinic (AP) sites generated by HALFPIPE superfamily proteins are cleaved by their inherent AP lyase activities, other AP endonuclease activities or heat-promoted β-elimination. Although the HALFPIPE superfamily protein R.PabI, obtained from a hyperthermophilic archaea, Pyrococcus abyssi, shows weak AP lyase activity, HALFPIPE superfamily proteins in mesophiles, such as R.CcoLI from Campylobacter coli and R. HpyAXII from Helicobacter pylori, show significant AP lyase activities. To identify the structural basis for the AP lyase activity of R.CcoLI, we determined the structure of R.CcoLI by X-ray crystallography. The structure of R.CcoLI, obtained at 2.35-Å resolution, shows that a conserved lysine residue (Lys71), which is stabilized by a characteristic β-sheet structure of R.CcoLI, protrudes into the active site. The results of mutational assays indicate that Lys71 is important for the AP lyase activity of R.CcoLI. Our results help to elucidate the mechanism by which HALFPIPE superfamily proteins from mesophiles efficiently introduce double-strand breaks to specific sites on double-stranded DNA.
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Affiliation(s)
- Ken-Ichi Miyazono
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Delong Wang
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tomoko Ito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo, 113-8657, Japan.
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7
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Kisiala M, Kowalska M, Pastor M, Korza HJ, Czapinska H, Bochtler M. Restriction endonucleases that cleave RNA/DNA heteroduplexes bind dsDNA in A-like conformation. Nucleic Acids Res 2020; 48:6954-6969. [PMID: 32459314 PMCID: PMC7337904 DOI: 10.1093/nar/gkaa403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 04/30/2020] [Accepted: 05/18/2020] [Indexed: 11/13/2022] Open
Abstract
Restriction endonucleases naturally target DNA duplexes. Systematic screening has identified a small minority of these enzymes that can also cleave RNA/DNA heteroduplexes and that may therefore be useful as tools for RNA biochemistry. We have chosen AvaII (G↓GWCC, where W stands for A or T) as a representative of this group of restriction endonucleases for detailed characterization. Here, we report crystal structures of AvaII alone, in specific complex with partially cleaved dsDNA, and in scanning complex with an RNA/DNA hybrid. The specific complex reveals a novel form of semi-specific dsDNA readout by a hexa-coordinated metal cation, most likely Ca2+ or Mg2+. Substitutions of residues anchoring this non-catalytic metal ion severely impair DNA binding and cleavage. The dsDNA in the AvaII complex is in the A-like form. This creates space for 2′-OH groups to be accommodated without intra-nucleic acid steric conflicts. PD-(D/E)XK restriction endonucleases of known structure that bind their dsDNA targets in the A-like form cluster into structurally similar groups. Most such enzymes, including some not previously studied in this respect, cleave RNA/DNA heteroduplexes. We conclude that A-form dsDNA binding is a good predictor for RNA/DNA cleavage activity.
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Affiliation(s)
- Marlena Kisiala
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland.,Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw, Poland.,Biological and Chemical Research Centre, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Monika Kowalska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
| | - Michal Pastor
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland.,Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Henryk J Korza
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Honorata Czapinska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland.,Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Matthias Bochtler
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland.,Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw, Poland
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8
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Miyazono KI, Wang D, Ito T, Tanokura M. Distortion of double-stranded DNA structure by the binding of the restriction DNA glycosylase R.PabI. Nucleic Acids Res 2020; 48:5106-5118. [PMID: 32232412 PMCID: PMC7229829 DOI: 10.1093/nar/gkaa184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/10/2020] [Accepted: 03/12/2020] [Indexed: 02/07/2023] Open
Abstract
R.PabI is a restriction DNA glycosylase that recognizes the sequence 5′-GTAC-3′ and hydrolyses the N-glycosidic bond of adenine in the recognition sequence. R.PabI drastically bends and unwinds the recognition sequence of double-stranded DNA (dsDNA) and flips the adenine and guanine bases in the recognition sequence into the catalytic and recognition sites on the protein surface. In this study, we determined the crystal structure of the R.PabI-dsDNA complex in which the dsDNA is drastically bent by the binding of R.PabI but the base pairs are not unwound. This structure is predicted to be important for the indirect readout of the recognition sequence by R.PabI. In the complex structure, wedge loops of the R.PabI dimer are inserted into the minor groove of dsDNA to stabilize the deformed dsDNA structure. A base stacking is distorted between the two wedge-inserted regions. R.PabI is predicted to utilize the distorted base stacking for the detection of the recognition sequence.
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Affiliation(s)
- Ken-Ichi Miyazono
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo 113-8657, Japan
| | - Delong Wang
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomoko Ito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi Bunkyo-ku, Tokyo 113-8657, Japan
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9
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Cuculis L, Zhao C, Abil Z, Zhao H, Shukla D, Schroeder CM. Divalent cations promote TALE DNA-binding specificity. Nucleic Acids Res 2020; 48:1406-1422. [PMID: 31863586 PMCID: PMC7026652 DOI: 10.1093/nar/gkz1174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/18/2019] [Accepted: 12/06/2019] [Indexed: 02/06/2023] Open
Abstract
Recent advances in gene editing have been enabled by programmable nucleases such as transcription activator-like effector nucleases (TALENs) and CRISPR–Cas9. However, several open questions remain regarding the molecular machinery in these systems, including fundamental search and binding behavior as well as role of off-target binding and specificity. In order to achieve efficient and specific cleavage at target sites, a high degree of target site discrimination must be demonstrated for gene editing applications. In this work, we studied the binding affinity and specificity for a series of TALE proteins under a variety of solution conditions using in vitro fluorescence methods and molecular dynamics (MD) simulations. Remarkably, we identified that TALEs demonstrate high sequence specificity only upon addition of small amounts of certain divalent cations (Mg2+, Ca2+). However, under purely monovalent salt conditions (K+, Na+), TALEs bind to specific and non-specific DNA with nearly equal affinity. Divalent cations preferentially bind to DNA over monovalent cations, which attenuates non-specific interactions between TALEs and DNA and further stabilizes specific interactions. Overall, these results uncover new mechanistic insights into the binding action of TALEs and further provide potential avenues for engineering and application of TALE- or TALEN-based systems for genome editing and regulation.
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Affiliation(s)
| | - Chuankai Zhao
- Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA
| | - Zhanar Abil
- Department of Biochemistry, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Chemistry, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Department of Biochemistry, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA.,National Center for Supercomputing Applications, Urbana, IL 61801, USA.,NIH Center for Macromolecular Modeling and Bioinformatics, Urbana, IL 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Charles M Schroeder
- Department of Chemistry, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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10
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Leven I, Levy Y. Quantifying the two-state facilitated diffusion model of protein-DNA interactions. Nucleic Acids Res 2019; 47:5530-5538. [PMID: 31045207 PMCID: PMC6582340 DOI: 10.1093/nar/gkz308] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 04/13/2019] [Accepted: 04/17/2019] [Indexed: 01/13/2023] Open
Abstract
The current report extends the facilitated diffusion model to account for conflict between the search and recognition binding modes adopted by DNA-binding proteins (DBPs) as they search DNA and subsequently recognize and bind to their specific binding site. The speed of the search dynamics is governed by the energetic ruggedness of the protein-DNA landscape, whereas the rate for the recognition process is mostly dictated by the free energy barrier for the transition between the DBP's search and recognition binding modes. We show that these two modes are negatively coupled, such that fast 1D sliding and rapid target site recognition probabilities are unlikely to coexist. Thus, a tradeoff occurs between optimizing the timescales for finding and binding the target site. We find that these two kinetic properties can be balanced to produce a fast timescale for the total target search and recognition process by optimizing frustration. Quantification of the facilitated diffusion model by including a frustration term enables it to explain several experimental observations concerning search and recognition speeds. The extended model captures experimental estimate of the energetic ruggedness of the protein-DNA landscape and predicts how various molecular properties of protein-DNA binding affect recognition kinetics. Particularly, point mutations may change the frustration and so affect protein association with DNA, thus providing a means to modulate protein-DNA affinity by manipulating the protein's association or dissociation reactions.
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Affiliation(s)
- Itai Leven
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaakov Levy
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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11
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Piatt SC, Loparo JJ, Price AC. The Role of Noncognate Sites in the 1D Search Mechanism of EcoRI. Biophys J 2019; 116:2367-2377. [PMID: 31113551 PMCID: PMC6588823 DOI: 10.1016/j.bpj.2019.04.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 04/18/2019] [Accepted: 04/29/2019] [Indexed: 02/02/2023] Open
Abstract
A one-dimensional (1D) search is an essential step in DNA target recognition. Theoretical studies have suggested that the sequence dependence of 1D diffusion can help resolve the competing demands of a fast search and high target affinity, a conflict known as the speed-selectivity paradox. The resolution requires that the diffusion energy landscape is correlated with the underlying specific binding energies. In this work, we report observations of a 1D search by quantum dot-labeled EcoRI. Our data supports the view that proteins search DNA via rotation-coupled sliding over a corrugated energy landscape. We observed that whereas EcoRI primarily slides along DNA at low salt concentrations, at higher concentrations, its diffusion is a combination of sliding and hopping. We also observed long-lived pauses at genomic star sites, which differ by a single nucleotide from the target sequence. To reconcile these observations with prior biochemical and structural data, we propose a model of search in which the protein slides over a sequence-independent energy landscape during fast search but rapidly interconverts with a "hemispecific" binding mode in which a half site is probed. This half site interaction stabilizes the transition to a fully specific mode of binding, which can then lead to target recognition.
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Affiliation(s)
- Sadie C Piatt
- Department of Chemistry and Physics, Emmanuel College, Boston, Massachusetts
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts.
| | - Allen C Price
- Department of Chemistry and Physics, Emmanuel College, Boston, Massachusetts.
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12
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Liao Q, Lüking M, Krüger DM, Deindl S, Elf J, Kasson PM, Lynn Kamerlin SC. Long Time-Scale Atomistic Simulations of the Structure and Dynamics of Transcription Factor-DNA Recognition. J Phys Chem B 2019; 123:3576-3590. [PMID: 30952192 DOI: 10.1021/acs.jpcb.8b12363] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent years have witnessed an explosion of interest in computational studies of DNA binding proteins, including both coarse-grained and atomistic simulations of transcription factor-DNA recognition, to understand how these transcription factors recognize their binding sites on the DNA with such exquisite specificity. The present study performs microsecond time scale all-atom simulations of the dimeric form of the lactose repressor (LacI), both in the absence of any DNA and in the presence of both specific and nonspecific complexes, considering three different DNA sequences. We examine, specifically, the conformational differences between specific and nonspecific protein-DNA interactions, as well as the behavior of the helix-turn-helix motif of LacI when interacting with the DNA. Our simulations suggest that stable LacI binding occurs primarily to bent A-form DNA, with a loss of LacI conformational entropy and optimization of correlated conformational equilibria across the protein. In addition, binding to the specific operator sequence involves a slightly larger number of stabilizing DNA-protein hydrogen bonds (in comparison to nonspecific complexes), which may account for the experimentally observed specificity for this operator. In doing so, our simulations provide a detailed atomistic description of potential structural drivers for LacI selectivity.
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Affiliation(s)
- Qinghua Liao
- Science for Life Laboratory, Department of Chemistry-BMC , Uppsala University , BMC Box 576, S-751 24 Uppsala , Sweden
| | - Malin Lüking
- Science for Life Laboratory, Department of Chemistry-BMC , Uppsala University , BMC Box 576, S-751 24 Uppsala , Sweden
| | - Dennis M Krüger
- Science for Life Laboratory, Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 23 Uppsala , Sweden.,Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, Bioinformatics Unit , German Center for Neurodegenerative Diseases, Göttingen , von Siebold Strasse 3A , 37075 Göttingen , Germany
| | - Sebastian Deindl
- Science for Life Laboratory, Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 23 Uppsala , Sweden
| | - Johan Elf
- Science for Life Laboratory, Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 23 Uppsala , Sweden
| | - Peter M Kasson
- Science for Life Laboratory, Department of Cell and Molecular Biology , Uppsala University , BMC Box 596, S-751 23 Uppsala , Sweden
| | - Shina Caroline Lynn Kamerlin
- Science for Life Laboratory, Department of Chemistry-BMC , Uppsala University , BMC Box 576, S-751 24 Uppsala , Sweden
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13
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Abstract
CRISPR-Cas9 is a bacterial immune system with exciting applications for genome editing. In spite of extensive experimental characterization, the active site chemistry of the RuvC domain-which performs DNA cleavages-has remained elusive. Its knowledge is key for structure-based engineering aimed at improving DNA cleavages. Here, we deliver an in-depth characterization by using quantum-classical (QM/MM) molecular dynamics (MD) simulations and a Gaussian accelerated MD method, coupled with bioinformatics analysis. We disclose a two-metal aided architecture in the RuvC active site, which is poised to operate DNA cleavages, in analogy with other DNA/RNA processing enzymes. The conformational dynamics of the RuvC domain further reveals that an "arginine finger" stably contacts the scissile phosphate, with the function of stabilizing the active complex. Remarkably, the formation of a catalytically competent state of the RuvC domain is only observed upon the conformational activation of the other nuclease domain of CRISPR-Cas9-i.e., the HNH domain-such allowing concerted cleavages of double stranded DNA. This structure is in agreement with the available experimental data and remarkably differs from previous models based on classical mechanics, demonstrating also that only quantum mechanical simulations can accurately describe the metal-aided active site in CRISPR-Cas9. This fully catalytic structure-in which both the HNH and RuvC domains are prone to perform DNA cleavages-constitutes a stepping-stone for understanding DNA cleavage and specificity. It calls for novel experimental verifications and offers the structural foundations for engineering efforts aimed at improving the genome editing capability of CRISPR-Cas9.
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Affiliation(s)
- Giulia Palermo
- Department of Bioengineering, Bourns College of Engineering , University of California Riverside , 900 University Avenue , Riverside , California 92521 , United States
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14
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Wu SJ, Schuergers N, Lin KH, Gillen AJ, Corminboeuf C, Boghossian AA. Restriction Enzyme Analysis of Double-Stranded DNA on Pristine Single-Walled Carbon Nanotubes. ACS APPLIED MATERIALS & INTERFACES 2018; 10:37386-37395. [PMID: 30277379 DOI: 10.1021/acsami.8b12287] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanoprobes such as single-walled carbon nanotubes (SWCNTs) are capable of label-free detection that benefits from intrinsic and photostable near-infrared fluorescence. Despite the growing number of SWCNT-based applications, uncertainty surrounding the nature of double-stranded DNA (dsDNA) immobilization on pristine SWCNTs has limited their use as optical sensors for probing DNA-protein interactions. To address this limitation, we study enzyme activity on unmodified dsDNA strands immobilized on pristine SWCNTs. Restriction enzyme activity on various dsDNA sequences was used to verify the retention of the dsDNA's native conformation on the nanotube surface and to quantitatively compare the degree of dsDNA accessibility. We report a 2.8-fold enhancement in initial enzyme activity in the presence of surfactants. Förster resonance electron transfer (FRET) analysis attributes this enhancement to increased dsDNA displacement from the SWCNT surface. Furthermore, the accessibility of native dsDNA was found to vary with DNA configuration and the spacing between the restriction site and the nanotube surface, with a minimum spacing of four base pairs (bp) from the anchoring site needed to preserve enzyme activity. Molecular dynamics (MD) simulations verify that the anchored dsDNA remains within the vicinity of the SWCNT, revealing an unprecedented bimodal displacement of the bp nearest to SWCNT surface. Together, these findings illustrate the successful immobilization of native dsDNA on pristine SWCNTs, offering a new near-infrared platform for exploring vital DNA processes.
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Affiliation(s)
- Shang-Jung Wu
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Nils Schuergers
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Kun-Han Lin
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Alice J Gillen
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Clémence Corminboeuf
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Ardemis A Boghossian
- Institute of Chemical Sciences and Engineering (ISIC) , École Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
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15
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Privalov PL, Crane-Robinson C. Forces maintaining the DNA double helix and its complexes with transcription factors. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 135:30-48. [DOI: 10.1016/j.pbiomolbio.2018.01.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
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16
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Ramachandran R, Ciaccia PN, Filsuf TA, Jha JK, Chattoraj DK. Chromosome 1 licenses chromosome 2 replication in Vibrio cholerae by doubling the crtS gene dosage. PLoS Genet 2018; 14:e1007426. [PMID: 29795553 PMCID: PMC5991422 DOI: 10.1371/journal.pgen.1007426] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 06/06/2018] [Accepted: 05/17/2018] [Indexed: 12/20/2022] Open
Abstract
Initiation of chromosome replication in bacteria is precisely timed in the cell cycle. Bacteria that harbor multiple chromosomes face the additional challenge of orchestrating replication initiation of different chromosomes. In Vibrio cholerae, the smaller of its two chromosomes, Chr2, initiates replication after Chr1 such that both chromosomes terminate replication synchronously. The delay is due to the dependence of Chr2 initiation on the replication of a site, crtS, on Chr1. The mechanism by which replication of crtS allows Chr2 replication remains unclear. Here, we show that blocking Chr1 replication indeed blocks Chr2 replication, but providing an extra crtS copy in replication-blocked Chr1 permitted Chr2 replication. This demonstrates that unreplicated crtS copies have significant activity, and suggests that a role of replication is to double the copy number of the site that sufficiently increases its activity for licensing Chr2 replication. We further show that crtS activity promotes the Chr2-specific initiator function and that this activity is required in every cell cycle, as would be expected of a cell-cycle regulator. This study reveals how increase of gene dosage through replication can be utilized in a critical regulatory switch.
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Affiliation(s)
- Revathy Ramachandran
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Peter N. Ciaccia
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tara A. Filsuf
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jyoti K. Jha
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Dhruba K. Chattoraj
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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17
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Yesudhas D, Batool M, Anwar MA, Panneerselvam S, Choi S. Proteins Recognizing DNA: Structural Uniqueness and Versatility of DNA-Binding Domains in Stem Cell Transcription Factors. Genes (Basel) 2017; 8:genes8080192. [PMID: 28763006 PMCID: PMC5575656 DOI: 10.3390/genes8080192] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/22/2017] [Accepted: 07/25/2017] [Indexed: 12/17/2022] Open
Abstract
Proteins in the form of transcription factors (TFs) bind to specific DNA sites that regulate cell growth, differentiation, and cell development. The interactions between proteins and DNA are important toward maintaining and expressing genetic information. Without knowing TFs structures and DNA-binding properties, it is difficult to completely understand the mechanisms by which genetic information is transferred between DNA and proteins. The increasing availability of structural data on protein-DNA complexes and recognition mechanisms provides deeper insights into the nature of protein-DNA interactions and therefore, allows their manipulation. TFs utilize different mechanisms to recognize their cognate DNA (direct and indirect readouts). In this review, we focus on these recognition mechanisms as well as on the analysis of the DNA-binding domains of stem cell TFs, discussing the relative role of various amino acids toward facilitating such interactions. Unveiling such mechanisms will improve our understanding of the molecular pathways through which TFs are involved in repressing and activating gene expression.
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Affiliation(s)
- Dhanusha Yesudhas
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
| | - Maria Batool
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
| | - Muhammad Ayaz Anwar
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
| | - Suresh Panneerselvam
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
| | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
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18
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In-depth study of DNA binding of Cys2His2 finger domains in testis zinc-finger protein. PLoS One 2017; 12:e0175051. [PMID: 28384299 PMCID: PMC5383199 DOI: 10.1371/journal.pone.0175051] [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: 11/28/2016] [Accepted: 03/20/2017] [Indexed: 11/26/2022] Open
Abstract
Previously, we identified that both fingers 1 and 2 in the three Cys2His2 zinc-finger domains (TZD) of testis zinc-finger protein specifically bind to its cognate DNA; however, finger 3 is non-sequence–specific. To gain insights into the interaction mechanism, here we further investigated the DNA-binding characteristics of TZD bound to non-specific DNAs and its finger segments bound to cognate DNA. TZD in non-specific DNA binding showed smaller chemical shift perturbations, as expected. However, the direction of shift perturbation, change of DNA imino-proton NMR signal, and dynamics on the 15N backbone atom significantly differed between specific and non-specific binding. Using these unique characteristics, we confirmed that the three single-finger segments (TZD1, TZD2 and TZD3) and the two-finger segment (TZD23) non-specifically bind to the cognate DNA. In comparison, the other two-finger segment (TZD12) binding to the cognate DNA features simultaneous non-specific and semi-specific binding, both slowly exchanged in terms of NMR timescale. The process of TZD binding to the cognate DNA is likely stepwise: initially TZD non-specifically binds to DNA, then fingers 1 and 2 insert cooperatively into the major groove of DNA by semi-specific binding, and finally finger 3 non-specifically binds to DNA, which promotes the specific binding on fingers 1 and 2 and stabilizes the formation of a specific TZD–DNA complex.
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19
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Identification of protein structural elements responsible for the diversity of sequence preferences among Mini-III RNases. Sci Rep 2016; 6:38612. [PMID: 27924926 PMCID: PMC5141509 DOI: 10.1038/srep38612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/10/2016] [Indexed: 01/21/2023] Open
Abstract
Many known endoribonucleases select their substrates based on the presence of one or a few specific nucleotides at or near the cleavage site. In some cases, selectivity is also determined by the structural features of the substrate. We recently described the sequence-specific cleavage of double-stranded RNA by Mini-III RNase from Bacillus subtilis in vitro. Here, we characterized the sequence specificity of eight other members of the Mini-III RNase family from different bacterial species. High-throughput analysis of the cleavage products of Φ6 bacteriophage dsRNA indicated subtle differences in sequence preference between these RNases, which were confirmed and characterized by systematic analysis of the cleavage kinetics of a set of short dsRNA substrates. We also showed that the sequence specificities of Mini-III RNases are not reflected by different binding affinities for cognate and non-cognate sequences, suggesting that target selection occurs predominantly at the cleavage step. We were able to identify two structural elements, the α4 helix and α5b-α6 loop that were involved in target selection. Characterization of the sequence specificity of the eight Mini-III RNases may provide a basis for better understanding RNA substrate recognition by Mini-III RNases and adopting these enzymes and their engineered derivatives as tools for RNA research.
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20
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Wang D, Miyazono KI, Tanokura M. Tetrameric structure of the restriction DNA glycosylase R.PabI in complex with nonspecific double-stranded DNA. Sci Rep 2016; 6:35197. [PMID: 27731370 PMCID: PMC5059719 DOI: 10.1038/srep35197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/26/2016] [Indexed: 02/06/2023] Open
Abstract
R.PabI is a type II restriction enzyme that recognizes the 5′-GTAC-3′ sequence and belongs to the HALFPIPE superfamily. Although most restriction enzymes cleave phosphodiester bonds at specific sites by hydrolysis, R.PabI flips the guanine and adenine bases of the recognition sequence out of the DNA helix and hydrolyzes the N-glycosidic bond of the flipped adenine in a similar manner to DNA glycosylases. In this study, we determined the structure of R.PabI in complex with double-stranded DNA without the R.PabI recognition sequence by X-ray crystallography. The 1.9 Å resolution structure of the complex showed that R.PabI forms a tetrameric structure to sandwich the double-stranded DNA and the tetrameric structure is stabilized by four salt bridges. DNA binding and DNA glycosylase assays of the R.PabI mutants showed that the residues that form the salt bridges (R70 and D71) are essential for R.PabI to find the recognition sequence from the sea of nonspecific sequences. R.PabI is predicted to utilize the tetrameric structure to bind nonspecific double-stranded DNA weakly and slide along it to find the recognition sequence.
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Affiliation(s)
- Delong Wang
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ken-Ichi Miyazono
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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21
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Full-length p53 tetramer bound to DNA and its quaternary dynamics. Oncogene 2016; 36:1451-1460. [PMID: 27641333 DOI: 10.1038/onc.2016.321] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/15/2016] [Indexed: 01/04/2023]
Abstract
P53 is a major tumor suppressor that is mutated and inactivated in ~50% of all human cancers. Thus, reactivation of mutant p53 using small molecules has been a long sought-after anticancer therapeutic strategy. Full structural characterization of the full-length oligomeric p53 is challenging because of its complex architecture and multiple highly flexible regions. To explore p53 structural dynamics, here we developed a series of atomistic integrative models with available crystal structures of the full-length p53 (fl-p53) tetramer bound to three different DNA sequences: a p21 response element, a puma response element and a nonspecific DNA sequence. Explicitly solvated, all-atom molecular dynamics simulations of the three complexes (totaling nearly 1 μs of aggregate simulation time) yield final structures consistent with electron microscopy maps and, for the first time, show the direct interactions of the p53 C-terminal with DNA. Through a collective principal component analysis, we identify sequence-dependent differential quaternary binding modes of the p53 tetramer interfacing with DNA. Additionally, L1 loop dynamics of fl-p53 in the presence of DNA is revealed, and druggable pockets of p53 are identified via solvent mapping to aid future drug discovery studies.
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22
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De S, Okon M, Graves BJ, McIntosh LP. Autoinhibition of ETV6 DNA Binding Is Established by the Stability of Its Inhibitory Helix. J Mol Biol 2016; 428:1515-30. [PMID: 26920109 PMCID: PMC5575937 DOI: 10.1016/j.jmb.2016.02.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 02/14/2016] [Accepted: 02/16/2016] [Indexed: 02/06/2023]
Abstract
The ETS transcriptional repressor ETV6 (or TEL) is autoinhibited by an α-helix that sterically blocks its DNA-binding ETS domain. The inhibitory helix is marginally stable and unfolds when ETV6 binds to either specific or non-specific DNA. Using NMR spectroscopy, we show that folding of the inhibitory helix requires a buried charge-dipole interaction with helix H1 of the ETS domain. This interaction also contributes directly to autoinhibition by precluding a highly conserved dipole-enhanced hydrogen bond between the phosphodiester backbone of bound DNA and the N terminus of helix H1. To probe further the thermodynamic basis of autoinhibition, ETV6 variants were generated with amino acid substitutions introduced along the solvent exposed surface of the inhibitory helix. These changes were designed to increase the intrinsic helical propensity of the inhibitory helix without perturbing its packing interactions with the ETS domain. NMR-monitored amide hydrogen exchange measurements confirmed that the stability of the folded inhibitory helix increases progressively with added helix-promoting substitutions. This also results in progressively reinforced autoinhibition and decreased DNA-binding affinity. Surprisingly, locking the inhibitory helix onto the ETS domain by a disulfide bridge severely impairs, but does not abolish DNA binding. Weak interactions still occur via an interface displaced from the canonical ETS domain DNA-binding surface. Collectively, these studies establish a direct thermodynamic linkage between inhibitory helix stability and ETV6 autoinhibition, and demonstrate that helix unfolding does not strictly precede DNA binding. Modulating inhibitory helix stability provides a potential route for the in vivo regulation of ETV6 activity.
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Affiliation(s)
- Soumya De
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Mark Okon
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Barbara J Graves
- Department of Oncological Sciences, School of Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112-5550, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA
| | - Lawrence P McIntosh
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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23
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Kulkarni M, Nirwan N, van Aelst K, Szczelkun MD, Saikrishnan K. Structural insights into DNA sequence recognition by Type ISP restriction-modification enzymes. Nucleic Acids Res 2016; 44:4396-408. [PMID: 26975655 PMCID: PMC4872093 DOI: 10.1093/nar/gkw154] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/29/2016] [Indexed: 02/03/2023] Open
Abstract
Engineering restriction enzymes with new sequence specificity has been an unaccomplished challenge, presumably because of the complexity of target recognition. Here we report detailed analyses of target recognition by Type ISP restriction-modification enzymes. We determined the structure of the Type ISP enzyme LlaGI bound to its target and compared it with the previously reported structure of a close homologue that binds to a distinct target, LlaBIII. The comparison revealed that, although the two enzymes use almost a similar set of structural elements for target recognition, the residues that read the bases vary. Change in specificity resulted not only from appropriate substitution of amino acids that contacted the bases but also from new contacts made by positionally distinct residues directly or through a water bridge. Sequence analyses of 552 Type ISP enzymes showed that the structural elements involved in target recognition of LlaGI and LlaBIII were structurally well-conserved but sequentially less-conserved. In addition, the residue positions within these structural elements were under strong evolutionary constraint, highlighting the functional importance of these regions. The comparative study helped decipher a partial consensus code for target recognition by Type ISP enzymes.
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Affiliation(s)
- Manasi Kulkarni
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Neha Nirwan
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Kara van Aelst
- DNA-Protein Interactions Unit, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Kayarat Saikrishnan
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
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24
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Hauser K, Essuman B, He Y, Coutsias E, Garcia-Diaz M, Simmerling C. A human transcription factor in search mode. Nucleic Acids Res 2015; 44:63-74. [PMID: 26673724 PMCID: PMC4705650 DOI: 10.1093/nar/gkv1091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/07/2015] [Indexed: 12/14/2022] Open
Abstract
Transcription factors (TF) can change shape to bind and recognize DNA, shifting the energy landscape from a weak binding, rapid search mode to a higher affinity recognition mode. However, the mechanism(s) driving this conformational change remains unresolved and in most cases high-resolution structures of the non-specific complexes are unavailable. Here, we investigate the conformational switch of the human mitochondrial transcription termination factor MTERF1, which has a modular, superhelical topology complementary to DNA. Our goal was to characterize the details of the non-specific search mode to complement the crystal structure of the specific binding complex, providing a basis for understanding the recognition mechanism. In the specific complex, MTERF1 binds a significantly distorted and unwound DNA structure, exhibiting a protein conformation incompatible with binding to B-form DNA. In contrast, our simulations of apo MTERF1 revealed significant flexibility, sampling structures with superhelical pitch and radius complementary to the major groove of B-DNA. Docking these structures to B-DNA followed by unrestrained MD simulations led to a stable complex in which MTERF1 was observed to undergo spontaneous diffusion on the DNA. Overall, the data support an MTERF1-DNA binding and recognition mechanism driven by intrinsic dynamics of the MTERF1 superhelical topology.
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Affiliation(s)
- Kevin Hauser
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Yiqing He
- Great Neck South High School, Great Neck, NY 11023, USA
| | - Evangelos Coutsias
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Miguel Garcia-Diaz
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Carlos Simmerling
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
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25
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Cartailler J, Reingruber J. Facilitated diffusion framework for transcription factor search with conformational changes. Phys Biol 2015. [PMID: 26200216 DOI: 10.1088/1478-3975/12/4/046012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cellular responses often require the fast activation or repression of specific genes, which depends on transcription factors (TFs) that have to quickly find the promoters of these genes within a large genome. TFs search for their DNA promoter target by alternating between bulk diffusion and sliding along the DNA, a mechanism known as facilitated diffusion. We study a facilitated diffusion framework with switching between three search modes: a bulk mode and two sliding modes triggered by conformational changes between two protein conformations. In one conformation (search mode) the TF interacts unspecifically with the DNA backbone resulting in fast sliding. In the other conformation (recognition mode) it interacts specifically and strongly with DNA base pairs leading to slow displacement. From the bulk, a TF associates with the DNA at a random position that is correlated with the previous dissociation point, which implicitly is a function of the DNA structure. The target affinity depends on the conformation. We derive exact expressions for the mean first passage time (MFPT) to bind to the promoter and the conditional probability to bind before detaching when arriving at the promoter site. We systematically explore the parameter space and compare various search scenarios. We compare our results with experimental data for the dimeric Lac repressor search in E. coli bacteria. We find that a coiled DNA conformation is absolutely necessary for a fast MFPT. With frequent spontaneous conformational changes, a fast search time is achieved even when a TF becomes immobilized in the recognition state due to the specific bindings. We find a MFPT compatible with experimental data in presence of a specific TF-DNA interaction energy that has a Gaussian distribution with a large variance.
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26
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Abstract
We investigate the electrostatics, energetics, and dynamics of dendrimer-DNA interactions that mimic protein-DNA complexes as a means to design facilitated mechanisms by which dendrimers can slide and search DNA for targets. By using all-atom molecular dynamics simulations, we calculated the free energy profiles of dendrimer-binding around the DNA via umbrella sampling. We also calculated electrostatic interaction maps in comparison to proteins, as well as the dynamical changes induced by DNA-dendrimer interactions via NMR-measurable order parameters. Our results show that for dendrimers to go around DNA, there is a free-energy barrier of 8.5 kcal/mol from the DNA major groove to DNA minor groove, with a minimum in the major groove. This barrier height makes it unlikely for an all-amine dendrimer to slide along DNA longitudinally, but following a helical path may be possible along the major groove. Comparison of the nonbonded interaction energy and the interaction free-energy profiles reveal a considerable entropic cost as the dendrimer binds to DNA. This is also supported by the mobility patterns obtained from NMR-measurable order parameter values, which show a decreased mobility of the dendrimer N-H bond vectors in the DNA-binding mode.
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Affiliation(s)
- Emel Ficici
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Ioan Andricioaei
- Department of Chemistry, University of California, Irvine, California 92697, United States
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27
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Schormann N, Banerjee S, Ricciardi R, Chattopadhyay D. Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA Glycosylase. BMC STRUCTURAL BIOLOGY 2015; 15:10. [PMID: 26031450 PMCID: PMC4450493 DOI: 10.1186/s12900-015-0037-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/21/2015] [Indexed: 01/10/2023]
Abstract
BACKGROUND Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. RESULTS This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This also represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. Comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. CONCLUSION The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.
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Affiliation(s)
- Norbert Schormann
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Surajit Banerjee
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne, Chicago, IL, 60439, USA.
| | - Robert Ricciardi
- Department of Microbiology, School of Dental Medicine, Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Debasish Chattopadhyay
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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Chen X, Velmurugu Y, Zheng G, Park B, Shim Y, Kim Y, Liu L, Van Houten B, He C, Ansari A, Min JH. Kinetic gating mechanism of DNA damage recognition by Rad4/XPC. Nat Commun 2015; 6:5849. [PMID: 25562780 PMCID: PMC4354021 DOI: 10.1038/ncomms6849] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 11/13/2014] [Indexed: 01/24/2023] Open
Abstract
The xeroderma pigmentosum C (XPC) complex initiates nucleotide excision repair by recognizing DNA lesions before recruiting downstream factors. How XPC detects structurally diverse lesions embedded within normal DNA is unknown. Here we present a crystal structure that captures the yeast XPC orthologue (Rad4) on a single register of undamaged DNA. The structure shows that a disulphide-tethered Rad4 flips out normal nucleotides and adopts a conformation similar to that seen with damaged DNA. Contrary to many DNA repair enzymes that can directly reject non-target sites as structural misfits, our results suggest that Rad4/XPC uses a kinetic gating mechanism whereby lesion selectivity arises from the kinetic competition between DNA opening and the residence time of Rad4/XPC per site. This mechanism is further supported by measurements of Rad4-induced lesion-opening times using temperature-jump perturbation spectroscopy. Kinetic gating may be a general mechanism used by site-specific DNA-binding proteins to minimize time-consuming interrogations of non-target sites. XPC nucleotide excision repair factor is key to starting the repair of diverse helix-distorting DNA lesions caused by environmental insults. Here, the authors propose a kinetic gating mechanism whereby XPC recognizes DNA lesions by preferentially opening damaged sites while readily diffusing away from undamaged sites.
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Affiliation(s)
- Xuejing Chen
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
| | - Yogambigai Velmurugu
- Department of Physics, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
| | - Guanqun Zheng
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637, USA
| | - Beomseok Park
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
| | - Yoonjung Shim
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
| | - Youngchang Kim
- Structural Biology Center, Biosciences Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - Lili Liu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine and University of Pittsburgh Cancer Institute, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, USA
| | - Bennett Van Houten
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine and University of Pittsburgh Cancer Institute, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, USA
| | - Chuan He
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637, USA
| | - Anjum Ansari
- 1] Department of Physics, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA [2] Department of Bioengineering, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
| | - Jung-Hyun Min
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607, USA
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Wettstein C, Kyne C, Doolan AM, Möhwald H, Crowley PB, Lisdat F. Study of cytochrome c-DNA interaction--evaluation of binding sites on the redox protein. NANOSCALE 2014; 6:13779-13786. [PMID: 25286363 DOI: 10.1039/c4nr05301j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Artificial assemblies consisting of the cationic cytochrome c (cyt c) and double-stranded DNA are interesting for the field of biohybrid systems because of the high electro-activity of the incorporated redox protein. However, little is known about the interactions between these two biomolecules. Here, the complex of reduced cyt c and a 41 base pair oligonucleotide was characterized in solution as a function of pH and ionic strength. Persistent cyt c-DNA agglomerates were observed by UV-vis and DLS (dynamic light scattering) at pH 5.0 and low ionic strength. The strength of the interaction was attenuated by raising the pH or the ionic strength. At pH 7.0 agglomerates were not formed, allowing interaction analysis by NMR spectroscopy. Using TROSY (transverse relaxation-optimized spectroscopy)-HSQC (heteronuclear single quantum coherence) experiments it was possible to identify the DNA binding site on the cyt c surface. Numerous residues surrounding the exposed heme edge of cyt c were involved in transient binding to DNA under these conditions. This result was supported by SEC (size exclusion chromatography) experiments at pH 7.0 showing that the interaction is sufficient for co-elution of cyt c and DNA.
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Affiliation(s)
- Christoph Wettstein
- Technical University of Applied Sciences Wildau, Institute of Applied Life Sciences, Biosystems Technology, Hochschulring 1, 15745 Wildau, Germany.
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30
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Furini S, Domene C. DNA recognition process of the lactose repressor protein studied via metadynamics and umbrella sampling simulations. J Phys Chem B 2014; 118:13059-65. [PMID: 25341013 DOI: 10.1021/jp505885j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The lactose repressor, LacI, finds its DNA target sites via a process that is faster than what it is expected from a diffusion-driven mechanism. This is possible thanks to nonspecific binding of LacI to DNA, followed by diffusion along the DNA molecule. The diffusion of the protein along DNA might lead to a fast-searching mechanism only if LacI binds with comparable strength to different nonspecific sequences and if, in addition, the value of the binding energy remarkably decreases in the presence of a binding site. The first condition would be favored by loose interactions with the base edges, while the second would take advantage from the opposite situation. In order to understand how the protein satisfies these two opposing requirements, the DNA recognition process was studied by a combination of umbrella sampling and metadynamics simulations. The simulations revealed that when aligned with a specific sequence, LacI establishes polar interactions with the base edges that require ∼4 kcal/mol to be disrupted. In contrast, these interactions are not stable when the protein is aligned with nonspecific sequences. These results confirm that LacI is able to efficiently recognize a specific sequence while sliding along DNA before any structural change of the protein-DNA complex occurs.
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Affiliation(s)
- Simone Furini
- Department of Medical Biotechnologies, University of Siena , viale Mario Bracci 16, I-53100, Siena, Italy
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31
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van Dongen SFM, Elemans JAAW, Rowan AE, Nolte RJM. Processive catalysis. Angew Chem Int Ed Engl 2014; 53:11420-8. [PMID: 25244684 DOI: 10.1002/anie.201404848] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Indexed: 02/02/2023]
Abstract
Nature's enzymes are an ongoing source of inspiration for scientists. The complex processes behind their selectivity and efficiency is slowly being unraveled, and these findings have spawned many biomimetic catalysts. However, nearly all focus on the conversion of small molecular substrates. Nature itself is replete with inventive catalytic systems which modify, replicate, or decompose entire polymers, often in a processive fashion. Such processivity can, for example, enhance the rate of catalysis by clamping to the polymer substrate, which imparts a large effective molarity. Reviewed herein are the various strategies for processivity in nature's arsenal and their properties. An overview of what has been achieved by chemists aiming to mimic one of nature's greatest tricks is also included.
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Affiliation(s)
- Stijn F M van Dongen
- Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen (The Netherlands).
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Dynamic conformational change regulates the protein-DNA recognition: an investigation on binding of a Y-family polymerase to its target DNA. PLoS Comput Biol 2014; 10:e1003804. [PMID: 25188490 PMCID: PMC4154647 DOI: 10.1371/journal.pcbi.1003804] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/10/2014] [Indexed: 12/02/2022] Open
Abstract
Protein-DNA recognition is a central biological process that governs the life of cells. A protein will often undergo a conformational transition to form the functional complex with its target DNA. The protein conformational dynamics are expected to contribute to the stability and specificity of DNA recognition and therefore may control the functional activity of the protein-DNA complex. Understanding how the conformational dynamics influences the protein-DNA recognition is still challenging. Here, we developed a two-basin structure-based model to explore functional dynamics in Sulfolobus solfataricus DNA Y-family polymerase IV (DPO4) during its binding to DNA. With explicit consideration of non-specific and specific interactions between DPO4 and DNA, we found that DPO4-DNA recognition is comprised of first 3D diffusion, then a short-range adjustment sliding on DNA and finally specific binding. Interestingly, we found that DPO4 is under a conformational equilibrium between multiple states during the binding process and the distributions of the conformations vary at different binding stages. By modulating the strength of the electrostatic interactions, the flexibility of the linker, and the conformational dynamics in DPO4, we drew a clear picture on how DPO4 dynamically regulates the DNA recognition. We argue that the unique features of flexibility and conformational dynamics in DPO4-DNA recognition have direct implications for low-fidelity translesion DNA synthesis, most of which is found to be accomplished by the Y-family DNA polymerases. Our results help complete the description of the DNA synthesis process for the Y-family polymerases. Furthermore, the methods developed here can be widely applied for future investigations on how various proteins recognize and bind specific DNA substrates. Protein-DNA recognition is crucial for many key biological processes in cells. Protein often undergoes large-scale conformational change during DNA recognition. However, the physical and global understanding of flexible protein-DNA binding is still challenging. Here, we developed a theoretical approach to investigate binding of a Y-family DNA polymerase to its target DNA during the DNA synthesis process. The results of electrostatic-controlled multi-step DNA binding process accompanied with multi-state conformational transition of protein occurring throughout are in remarkable agreement with experiments. During the process of protein-DNA recognition, the flexibility is found to facilitate both the conformational transition of protein (intra-chain dynamics) and DNA binding (inter-chain dynamics) simultaneously. Therefore, we provided a quantitative description of protein-DNA binding mechanism that flexibility or conformational change regulates DNA recognition dynamically, leading to high efficiency and specificity of function for protein-DNA recognition.
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34
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Pingoud A, Wilson GG, Wende W. Type II restriction endonucleases--a historical perspective and more. Nucleic Acids Res 2014; 42:7489-527. [PMID: 24878924 PMCID: PMC4081073 DOI: 10.1093/nar/gku447] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 12/17/2022] Open
Abstract
This article continues the series of Surveys and Summaries on restriction endonucleases (REases) begun this year in Nucleic Acids Research. Here we discuss 'Type II' REases, the kind used for DNA analysis and cloning. We focus on their biochemistry: what they are, what they do, and how they do it. Type II REases are produced by prokaryotes to combat bacteriophages. With extreme accuracy, each recognizes a particular sequence in double-stranded DNA and cleaves at a fixed position within or nearby. The discoveries of these enzymes in the 1970s, and of the uses to which they could be put, have since impacted every corner of the life sciences. They became the enabling tools of molecular biology, genetics and biotechnology, and made analysis at the most fundamental levels routine. Hundreds of different REases have been discovered and are available commercially. Their genes have been cloned, sequenced and overexpressed. Most have been characterized to some extent, but few have been studied in depth. Here, we describe the original discoveries in this field, and the properties of the first Type II REases investigated. We discuss the mechanisms of sequence recognition and catalysis, and the varied oligomeric modes in which Type II REases act. We describe the surprising heterogeneity revealed by comparisons of their sequences and structures.
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Affiliation(s)
- Alfred Pingoud
- Institute of Biochemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
| | - Geoffrey G Wilson
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938-2723, USA
| | - Wolfgang Wende
- Institute of Biochemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
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35
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Elimination of inter-domain interactions increases the cleavage fidelity of the restriction endonuclease DraIII. Protein Cell 2014; 5:357-68. [PMID: 24733184 PMCID: PMC3996161 DOI: 10.1007/s13238-014-0038-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 02/18/2014] [Indexed: 11/24/2022] Open
Abstract
DraIII is a type IIP restriction endonucleases (REases) that recognizes and creates a double strand break within the gapped palindromic sequence CAC↑NNN↓GTG of double-stranded DNA (↑ indicates nicking on the bottom strand; ↓ indicates nicking on the top strand). However, wild type DraIII shows significant star activity. In this study, it was found that the prominent star site is CAT↑GTT↓GTG, consisting of a star 5′ half (CAT) and a canonical 3′ half (GTG). DraIII nicks the 3′ canonical half site at a faster rate than the 5′ star half site, in contrast to the similar rate with the canonical full site. The crystal structure of the DraIII protein was solved. It indicated, as supported by mutagenesis, that DraIII possesses a ββα-metal HNH active site. The structure revealed extensive intra-molecular interactions between the N-terminal domain and the C-terminal domain containing the HNH active site. Disruptions of these interactions through site-directed mutagenesis drastically increased cleavage fidelity. The understanding of fidelity mechanisms will enable generation of high fidelity REases.
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36
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De S, Chan ACK, Coyne HJ, Bhachech N, Hermsdorf U, Okon M, Murphy MEP, Graves BJ, McIntosh LP. Steric mechanism of auto-inhibitory regulation of specific and non-specific DNA binding by the ETS transcriptional repressor ETV6. J Mol Biol 2014; 426:1390-406. [PMID: 24333486 PMCID: PMC4278593 DOI: 10.1016/j.jmb.2013.11.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/05/2013] [Accepted: 11/09/2013] [Indexed: 11/29/2022]
Abstract
DNA binding by the ETS transcriptional repressor ETV6 (or TEL) is auto-inhibited ~50-fold due to an α-helix that sterically blocks its ETS domain binding interface. Using NMR spectroscopy, we demonstrate that this marginally stable helix is unfolded, and not displaced to a non-inhibitory position, when ETV6 is bound to DNA containing a consensus (5')GGAA(3') recognition site. Although significantly lower in affinity, binding to non-specific DNA is auto-inhibited ~5-fold and is also accompanied by helix unfolding. Based on NMR chemical shift perturbations, both specific and non-specific DNA are bound via the same canonical ETS domain interface. However, spectral perturbations are smaller for the non-specific complex, suggesting weaker and less well-defined interactions than in the specific complex. In parallel, the crystal structure of ETV6 bound to a specific DNA duplex was determined. The structure of this complex reveals that a non-conserved histidine residue in the ETS domain recognition helix helps establish the specificity of ETV6 for DNA-binding sites containing (5')GGAA(3')versus(5')GGAT(3'). These studies provide a unified steric mechanism for attenuating ETV6 binding to both specific and non-specific DNA and expand the repertoire of characterized auto-inhibitory strategies utilized to regulate ETS factors.
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Affiliation(s)
- Soumya De
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Anson C K Chan
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - H Jerome Coyne
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Niraja Bhachech
- Department of Oncological Sciences, University of Utah School of Medicine, and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112-5550, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA
| | - Ulrike Hermsdorf
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Mark Okon
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Michael E P Murphy
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Barbara J Graves
- Department of Oncological Sciences, University of Utah School of Medicine, and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112-5550, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA
| | - Lawrence P McIntosh
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
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37
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Xiao S, Klein ML, LeBard DN, Levine BG, Liang H, MacDermaid CM, Alfonso-Prieto M. Magnesium-Dependent RNA Binding to the PA Endonuclease Domain of the Avian Influenza Polymerase. J Phys Chem B 2014; 118:873-89. [DOI: 10.1021/jp408383g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Shiyan Xiao
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Michael L. Klein
- Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - David N. LeBard
- Department of Chemistry, Yeshiva University, New York, New York 10033, United States
| | - Benjamin G. Levine
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
| | - Haojun Liang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Christopher M. MacDermaid
- Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Mercedes Alfonso-Prieto
- Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States
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38
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Terakawa T, Takada S. RESPAC: Method to Determine Partial Charges in Coarse-Grained Protein Model and Its Application to DNA-Binding Proteins. J Chem Theory Comput 2014; 10:711-21. [DOI: 10.1021/ct4007162] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tsuyoshi Terakawa
- Department of Biophysics,
Graduate School of Science, Kyoto University, Kitashirakawa Owake-cho, Sakyo, Kyoto, 606-8501, Japan
| | - Shoji Takada
- Department of Biophysics,
Graduate School of Science, Kyoto University, Kitashirakawa Owake-cho, Sakyo, Kyoto, 606-8501, Japan
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39
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Khazanov N, Marcovitz A, Levy Y. Asymmetric DNA-search dynamics by symmetric dimeric proteins. Biochemistry 2013; 52:5335-44. [PMID: 23866074 DOI: 10.1021/bi400357m] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We focus on dimeric DNA-binding proteins from two well-studied families: orthodox type II restriction endonucleases (REs) and transcription factors (TFs). Interactions of the protein's recognition sites with the DNA and, particularly, the contribution of each of the monomers to one-dimensional (1D) sliding along nonspecific DNA were studied using computational tools. Coarse-grained molecular dynamics simulations of DNA scanning by various TFs and REs provide insights into how the symmetry of a homodimer can be broken while they nonspecifically interact with DNA. The characteristics of protein sliding along DNA, such as the average sliding length, partitioning between 1D and 3D search, and the one-dimensional diffusion coefficient D1, strongly depend on the salt concentration, which in turn affects the probability of the two monomers adopting a cooperative symmetric sliding mechanism. Indeed, we demonstrate that maximal DNA search efficiency is achieved when the protein adopts an asymmetric search mode in which one monomer slides while its partner hops. We find that proteins classified as TFs have a higher affinity for the DNA, longer sliding lengths, and an increased probability of symmetric sliding in comparison with REs. Moreover, TFs can perform their biological function over a much wider range of salt concentrations than REs. Our results demonstrate that the different biological functions of DNA-binding proteins are related to the different nonspecific DNA search mechanisms they adopt.
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Affiliation(s)
- Netaly Khazanov
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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40
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Yonetani Y, Kono H. Dissociation Free-Energy Profiles of Specific and Nonspecific DNA–Protein Complexes. J Phys Chem B 2013; 117:7535-45. [DOI: 10.1021/jp402664w] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Yoshiteru Yonetani
- Molecular Modeling and Simulation Group, Quantum Beam
Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Hidetoshi Kono
- Molecular Modeling and Simulation Group, Quantum Beam
Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
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41
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Marcovitz A, Levy Y. Weak frustration regulates sliding and binding kinetics on rugged protein-DNA landscapes. J Phys Chem B 2013; 117:13005-14. [PMID: 23668488 DOI: 10.1021/jp402296d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A fundamental step in gene-regulatory activities, such as repression, transcription, and recombination, is the binding of regulatory DNA-binding proteins (DBPs) to specific targets in the genome. To rapidly localize their regulatory genomic sites, DBPs reduce the dimensionality of the search space by combining three-dimensional (3D) diffusion in solution with one-dimensional (1D) sliding along DNA. However, the requirement to form a thermodynamically stable protein-DNA complex at the cognate genomic target sequence imposes a challenge on the protein because, as it navigates one-dimensionally along the genome, it may come in close contact with sites that share partial or even complete sequence similarity with the functional DNA sequence. This puzzling issue creates a conflict between two basic requirements: finding the cognate site quickly and stably binding it. Here, we structurally assessed the interface adopted by a variety of DBPs to bind DNA specifically and nonspecifically, and found that many DBPs utilize one interface to specifically recognize a DNA sequence and another to assist in propagating along the DNA through nonspecific associations. While these two interfaces overlap each other in some proteins, they present partial overlap in others and frustrate the protein-DNA interface. Using coarse-grained molecular dynamics simulations, we demonstrate that the existence of frustration in DBPs is a compromise between rapid 1D diffusion along other regions in the genome (high frustration smoothens the landscape for sliding) and rapid formation of a stable and essentially active protein-DNA complex (low frustration reduces the free energy barrier for switching between the two binding modes).
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Affiliation(s)
- Amir Marcovitz
- Department of Structural Biology, Weizmann Institute of Science , Rehovot, 76100, Israel
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42
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Sidorova NY, Scott T, Rau DC. DNA concentration-dependent dissociation of EcoRI: direct transfer or reaction during hopping. Biophys J 2013; 104:1296-303. [PMID: 23528089 DOI: 10.1016/j.bpj.2013.01.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/16/2013] [Accepted: 01/18/2013] [Indexed: 11/29/2022] Open
Abstract
Direct transfer of proteins between DNA helices is a recognized important feature of the recognition site search process. Direct transfer is characterized by a dissociation rate that depends on total DNA concentration. This is taken as evidence for the formation of an intermediate DNA-protein-DNA ternary complex. We find that the dissociation rate of EcoRI-DNA-specific complexes at 80 mM NaCl depends on the concentration of competitor oligonucleotide suggesting that direct transfer contributes to EcoRI dissociation. This dependence on competitor DNA concentration is not seen at 180 mM salt. A careful examination of the salt concentration dependence of the dissociation rate, however, shows that the predictions for the formation of a ternary complex are not observed experimentally. The findings can be rationalized by considering that just after dissociating from a DNA fragment the protein remains in close proximity to that fragment, can reassociate with it, and diffuse back to the recognition site rather than bind to an oligonucleotide in solution, a hopping excursion. The probability that a protein will bind to an oligonucleotide during a hop can be approximately calculated and shown to explain the data. A dependence of the dissociation rate of a DNA-protein complex on competitor DNA concentration does not necessarily mean direct transfer.
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Affiliation(s)
- Nina Y Sidorova
- The Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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43
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Furini S, Barbini P, Domene C. DNA-recognition process described by MD simulations of the lactose repressor protein on a specific and a non-specific DNA sequence. Nucleic Acids Res 2013; 41:3963-72. [PMID: 23430151 PMCID: PMC3627591 DOI: 10.1093/nar/gkt099] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The lactose repressor protein may bind DNA in two possible configurations: a specific one, if the DNA sequence corresponds to a binding site, and a non-specific one otherwise. To find its target sequences, the lactose repressor first binds non-specifically to DNA, and subsequently, it rapidly searches for a binding site. Atomic structures of non-specific and specific complexes are available from crystallographic and nuclear magnetic resonance experiments. However, what remains unknown is a detailed description of the steps that transform the non-specific complex into the specific one. Here, how the protein first recognizes its binding site has been studied using molecular dynamics simulations. The picture that emerges is that of a protein that is as mobile when interacting with non-specific DNA sequences as when free in solution. This high degree of mobility allows the protein to rapidly sample different DNA sequences. In contrast, when the protein encounters a binding site, the configuration ensemble collapses, and the protein sliding movements along the DNA sequence become scarce. The binding energies in the specific and non-specific complexes were analysed using the Molecular Mechanics Poisson Boltzmann Surface Area approach. These results represent a first step towards a throughout characterization of the DNA-recognition process.
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Affiliation(s)
- Simone Furini
- Department of Medical Biotechnology, University of Siena, viale Mario Bracci 12, I-53100 Siena, Italy.
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44
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Barbi M, Paillusson F. Protein–DNA Electrostatics. DYNAMICS OF PROTEINS AND NUCLEIC ACIDS 2013; 92:253-97. [DOI: 10.1016/b978-0-12-411636-8.00007-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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45
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Comer J, Ho A, Aksimentiev A. Toward detection of DNA-bound proteins using solid-state nanopores: insights from computer simulations. Electrophoresis 2012; 33:3466-79. [PMID: 23147918 PMCID: PMC3789251 DOI: 10.1002/elps.201200164] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 07/05/2012] [Accepted: 07/09/2012] [Indexed: 11/07/2022]
Abstract
Through all-atom molecular dynamics simulations, we explore the use of nanopores in thin synthetic membranes for detection and identification of DNA binding proteins. Reproducing the setup of a typical experiment, we simulate electric field driven transport of DNA-bound proteins through nanopores smaller in diameter than the proteins. As model systems, we use restriction enzymes EcoRI and BamHI specifically and nonspecifically bound to a fragment of dsDNA, and streptavidin and NeutrAvidin proteins bound to dsDNA and ssDNA via a biotin linker. Our simulations elucidate the molecular mechanics of nanopore-induced rupture of a protein-DNA complex, the effective force applied to the DNA-protein bond by the electrophoretic force in a nanopore, and the role of DNA-surface interactions in the rupture process. We evaluate the ability of the nanopore ionic current and the local electrostatic potential measured by an embedded electrode to report capture of DNA, capture of a DNA-bound protein, and rupture of the DNA-protein bond. We find that changes in the strain on dsDNA can reveal the rupture of a protein-DNA complex by altering both the nanopore ionic current and the potential of the embedded electrode. Based on the results of our simulations, we suggest a new method for detection of DNA binding proteins that utilizes peeling of a nicked double strand under the electrophoretic force in a nanopore.
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Affiliation(s)
- Jeffrey Comer
- Department of Physics and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Crenshaw CM, Nam K, Oo K, Kutchukian PS, Bowman BR, Karplus M, Verdine GL. Enforced presentation of an extrahelical guanine to the lesion recognition pocket of human 8-oxoguanine glycosylase, hOGG1. J Biol Chem 2012; 287:24916-28. [PMID: 22511791 PMCID: PMC3408145 DOI: 10.1074/jbc.m111.316497] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A poorly understood aspect of DNA repair proteins is their ability to identify exceedingly rare sites of damage embedded in a large excess of nearly identical undamaged DNA, while catalyzing repair only at the damaged sites. Progress toward understanding this problem has been made by comparing the structures and biochemical behavior of these enzymes when they are presented with either a target lesion or a corresponding undamaged nucleobase. Trapping and analyzing such DNA-protein complexes is particularly difficult in the case of base extrusion DNA repair proteins because of the complexity of the repair reaction, which involves extrusion of the target base from DNA followed by its insertion into the active site where glycosidic bond cleavage is catalyzed. Here we report the structure of a human 8-oxoguanine (oxoG) DNA glycosylase, hOGG1, in which a normal guanine from DNA has been forcibly inserted into the enzyme active site. Although the interactions of the nucleobase with the active site are only subtly different for G versus oxoG, hOGG1 fails to catalyze excision of the normal nucleobase. This study demonstrates that even if hOGG1 mistakenly inserts a normal base into its active site, the enzyme can still reject it on the basis of catalytic incompatibility.
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Affiliation(s)
- Charisse M. Crenshaw
- From the Departments of Molecular and Cellular Biology, ,Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Kwangho Nam
- Chemical and Chemical Biology, and ,Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138
| | | | - Peter S. Kutchukian
- Chemical and Chemical Biology, and ,Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Brian R. Bowman
- Chemical and Chemical Biology, and ,Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Martin Karplus
- Chemical and Chemical Biology, and ,the L'Institut de Science et d'Ingénierie Supramoléculaires, Université Louis Pasteur, 8 allée Gaspard Monge, 67000 Strasbourg, France
| | - Gregory L. Verdine
- Chemical and Chemical Biology, and ,Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, ,the Program in Cancer Chemical Biology and Chemical Biology Initiative, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and , To whom correspondence should be addressed. 12 Oxford St., Cambridge, MA 02138. Fax: 617-495-8755; E-mail:
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The binding process of a nonspecific enzyme with DNA. Biophys J 2011; 101:1139-47. [PMID: 21889451 DOI: 10.1016/j.bpj.2011.07.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/20/2011] [Accepted: 07/05/2011] [Indexed: 11/22/2022] Open
Abstract
Protein-DNA recognition of a nonspecific complex is modeled to understand the nature of the transient encounter states. We consider the structural and energetic features and the role of water in the DNA grooves in the process of protein-DNA recognition. Here we have used the nuclease domain of colicin E7 (N-ColE7) from Escherichia coli in complex with a 12-bp DNA duplex as the model system to consider how a protein approaches, encounters, and associates with DNA. Multiscale simulation studies using Brownian dynamics and molecular-dynamics simulations were performed to provide the binding process on multiple length- and timescales. We define the encounter states and identified the spatial and orientational aspects. For the molecular length-scales, we used molecular-dynamics simulations. Several intermediate binding states were found, which have different positions and orientations of protein around DNA including major and minor groove orientations. The results show that the contact number and the hydrated interfacial area are measures that facilitate better understanding of sequence-independent protein-DNA binding landscapes and pathways.
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Frustration in protein-DNA binding influences conformational switching and target search kinetics. Proc Natl Acad Sci U S A 2011; 108:17957-62. [PMID: 22003125 DOI: 10.1073/pnas.1109594108] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Rapid recognition of DNA target sites involves facilitated diffusion through which alternative sites are searched on genomic DNA. A key mechanism facilitating the localization of the target by a DNA-binding protein (DBP) is one-dimensional diffusion (sliding) in which electrostatic forces attract the protein to the DNA. As the protein reaches its target DNA site, it switches from purely electrostatic binding to a specific set of interactions with the DNA bases that also involves hydrogen bonding and van der Waals forces. High overlap between the DBP patches used for nonspecific and specific interactions with DNA may enable an immediate transition between the two binding modes following target site localization. By contrast, an imperfect overlap may result in greater frustration between the two potentially competing binding modes and consequently slower switching between them. A structural analysis of 125 DBPs indicates frustration between the two binding modes that results in a large difference between the orientations of the protein to the DNA when it slides compared to when it specifically interacts with DNA. Coarse-grained molecular dynamics simulations of in silico designed peptides comprising the full range of frustrations between the two interfaces show slower transition from nonspecific to specific DNA binding as the overlap between the patches involved in the two binding modes decreases. The complex search kinetics may regulate the search by eliminating trapping of the protein in semispecific sites while sliding.
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Collier IE, Legant W, Marmer B, Lubman O, Saffarian S, Wakatsuki T, Elson E, Goldberg GI. Diffusion of MMPs on the surface of collagen fibrils: the mobile cell surface-collagen substratum interface. PLoS One 2011; 6:e24029. [PMID: 21912660 PMCID: PMC3164694 DOI: 10.1371/journal.pone.0024029] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/01/2011] [Indexed: 11/18/2022] Open
Abstract
Remodeling of the extracellular matrix catalyzed by MMPs is central to morphogenetic phenomena during development and wound healing as well as in numerous pathologic conditions such as fibrosis and cancer. We have previously demonstrated that secreted MMP-2 is tethered to the cell surface and activated by MT1-MMP/TIMP-2-dependent mechanism. The resulting cell-surface collagenolytic complex (MT1-MMP)(2)/TIMP-2/MMP-2 can initiate (MT1-MMP) and complete (MMP-2) degradation of an underlying collagen fibril. The following question remained: What is the mechanism of substrate recognition involving the two structures of relatively restricted mobility, the cell surface enzymatic complex and a collagen fibril embedded in the ECM? Here we demonstrate that all the components of the complex are capable of processive movement on a surface of the collagen fibril. The mechanism of MT1-MMP movement is a biased diffusion with the bias component dependent on the proteolysis of its substrate, not adenosine triphosphate (ATP) hydrolysis. It is similar to that of the MMP-1 Brownian ratchet we described earlier. In addition, both MMP-2 and MMP-9 as well as their respective complexes with TIMP-1 and -2 are capable of Brownian diffusion on the surface of native collagen fibrils without noticeable dissociation while the dimerization of MMP-9 renders the enzyme immobile. Most instructive is the finding that the inactivation of the enzymatic activity of MT1-MMP has a detectable negative effect on the cell force developed in miniaturized 3D tissue constructs. We propose that the collagenolytic complex (MT1-MMP)(2)/TIMP-2/MMP-2 represents a Mobile Cell Surface-Collagen Substratum Interface. The biological implications of MT1-MMP acting as a molecular ratchet tethered to the cell surface in complex with MMP-2 suggest a new mechanism for the role of spatially regulated peri-cellular proteolysis in cell-matrix interactions.
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Affiliation(s)
- Ivan E. Collier
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Wesley Legant
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Barry Marmer
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Olga Lubman
- Department of Pathology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Saveez Saffarian
- Department of Physics, University of Utah, Salt Lake City, Utah, United States of America
| | - Tetsuro Wakatsuki
- Department of Physiology, Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Elliot Elson
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Gregory I. Goldberg
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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Uyar A, Kurkcuoglu O, Nilsson L, Doruker P. The elastic network model reveals a consistent picture on intrinsic functional dynamics of type II restriction endonucleases. Phys Biol 2011; 8:056001. [PMID: 21791727 DOI: 10.1088/1478-3975/8/5/056001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The vibrational dynamics of various type II restriction endonucleases, in complex with cognate/non-cognate DNA and in the apo form, are investigated with the elastic network model in order to reveal common functional mechanisms in this enzyme family. Scissor-like and tong-like motions observed in the slowest modes of all enzymes and their complexes point to common DNA recognition and cleavage mechanisms. Normal mode analysis further points out that the scissor-like motion has an important role in differentiating between cognate and non-cognate sequences at the recognition site, thus implying its catalytic relevance. Flexible regions observed around the DNA-binding site of the enzyme usually concentrate on the highly conserved β-strands, especially after DNA binding. These β-strands may have a structurally stabilizing role in functional dynamics for target site recognition and cleavage. In addition, hot spot residues based on high-frequency modes reveal possible communication pathways between the two distant cleavage sites in the enzyme family. Some of these hot spots also exist on the shortest path between the catalytic sites and are highly conserved.
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Affiliation(s)
- A Uyar
- Department of Chemical Engineering and Polymer Research Center, Bogazici University, 34342 Bebek, Istanbul, Turkey
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