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Park J, Youn HS, An JY, Lee Y, Eom SH, Wang J. Structure of New Binary and Ternary DNA Polymerase Complexes From Bacteriophage RB69. Front Mol Biosci 2021; 8:704813. [PMID: 34869578 PMCID: PMC8639217 DOI: 10.3389/fmolb.2021.704813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/30/2021] [Indexed: 11/29/2022] Open
Abstract
DNA polymerase plays a critical role in passing the genetic information of any living organism to its offspring. DNA polymerase from enterobacteria phage RB69 (RB69pol) has both polymerization and exonuclease activities and has been extensively studied as a model system for B-family DNA polymerases. Many binary and ternary complex structures of RB69pol are known, and they all contain a single polymerase-primer/template (P/T) DNA complex. Here, we report a crystal structure of the exonuclease-deficient RB69pol with the P/T duplex in a dimeric form at a resolution of 2.2 Å. The structure includes one new closed ternary complex with a single divalent metal ion bound and one new open binary complex in the pre-insertion state with a vacant dNTP-binding pocket. These complexes suggest that initial binding of the correct dNTP in the open state is much weaker than expected and that initial binding of the second divalent metal ion in the closed state is also much weaker than measured. Additional conformational changes are required to convert these complexes to high-affinity states. Thus, the measured affinities for the correct incoming dNTP and divalent metal ions are average values from many conformationally distinctive states. Our structure provides new insights into the order of the complex assembly involving two divalent metal ions. The biological relevance of specific interactions observed between one RB69pol and the P/T duplex bound to the second RB69pol observed within this dimeric complex is discussed.
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Affiliation(s)
- Jongseo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea
| | - Hyung-Seop Youn
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,BIO R&D Center, Ingredient Business Unit, Daesang Corporation, Gyeonggi-do, Korea
| | - Jun Yop An
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Virocure Inc., Seoul, Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Metabolic Regulation Research Center, Korea Research Institute of BIoscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Department of Chemistry, GIST, Gwangju, Korea
| | - Jimin Wang
- Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
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2
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Dangerfield TL, Kirmizialtin S, Johnson KA. Conformational dynamics during misincorporation and mismatch extension defined using a DNA polymerase with a fluorescent artificial amino acid. J Biol Chem 2021; 298:101451. [PMID: 34838820 PMCID: PMC8715121 DOI: 10.1016/j.jbc.2021.101451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/09/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022] Open
Abstract
High-fidelity DNA polymerases select the correct nucleotide over the structurally similar incorrect nucleotides with extremely high specificity while maintaining fast rates of incorporation. Previous analysis revealed the conformational dynamics and complete kinetic pathway governing correct nucleotide incorporation using a high-fidelity DNA polymerase variant containing a fluorescent unnatural amino acid. Here we extend this analysis to investigate the kinetics of nucleotide misincorporation and mismatch extension. We report the specificity constants for all possible misincorporations and characterize the conformational dynamics of the enzyme during misincorporation and mismatch extension. We present free energy profiles based on the kinetic measurements and discuss the effect of different steps on specificity. During mismatch incorporation and subsequent extension with the correct nucleotide, the rates of the conformational change and chemistry are both greatly reduced. The nucleotide dissociation rate, however, increases to exceed the rate of chemistry. To investigate the structural basis for discrimination against mismatched nucleotides, we performed all atom molecular dynamics simulations on complexes with either the correct or mismatched nucleotide bound at the polymerase active site. The simulations suggest that the closed form of the enzyme with a mismatch bound is greatly destabilized due to weaker interactions with active site residues, nonideal base pairing, and a large increase in the distance from the 3'-OH group of the primer strand to the α-phosphate of the incoming nucleotide, explaining the reduced rates of misincorporation. The observed kinetic and structural mechanisms governing nucleotide misincorporation reveal the general principles likely applicable to other high-fidelity DNA polymerases.
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Affiliation(s)
- Tyler L Dangerfield
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA
| | - Serdal Kirmizialtin
- Chemistry Program, Division of Science, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Kenneth A Johnson
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
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3
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Tavakoli A, Paul D, Mu H, Kuchlyan J, Baral S, Ansari A, Broyde S, Min JH. Light-induced modulation of DNA recognition by the Rad4/XPC damage sensor protein. RSC Chem Biol 2021; 2:523-536. [PMID: 34041491 PMCID: PMC8142930 DOI: 10.1039/d0cb00192a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Biomolecular structural changes upon binding/unbinding are key to their functions. However, characterization of such dynamical processes is difficult as it requires ways to rapidly and specifically trigger the assembly/disassembly as well as ways to monitor the resulting changes over time. Recently, various chemical strategies have been developed to use light to trigger changes in oligonucleotide structures, and thereby their activities. Here we report that photocleavable DNA can be used to modulate the DNA binding of the Rad4/XPC DNA repair complex using light. Rad4/XPC specifically recognizes diverse helix-destabilizing/distorting lesions including bulky organic adduct lesions and functions as a key initiator for the eukaryotic nucleotide excision repair (NER) pathway. We show that the 6-nitropiperonyloxymethyl (NPOM)-modified DNA is recognized by the Rad4 protein as a specific substrate and that the specific binding can be abolished by light-induced cleavage of the NPOM group from DNA in a dose-dependent manner. Fluorescence lifetime-based analyses of the DNA conformations suggest that free NPOM-DNA retains B-DNA-like conformations despite its bulky NPOM adduct, but Rad4-binding causes it to be heterogeneously distorted. Subsequent extensive conformational searches and molecular dynamics simulations demonstrate that NPOM in DNA can be housed in the major groove of the DNA, with stacking interactions among the nucleotide pairs remaining largely unperturbed and thus retaining overall B-DNA conformation. Our work suggests that photoactivable DNA may be used as a DNA lesion surrogate to study DNA repair mechanisms such as nucleotide excision repair. Rad4/XPC DNA damage sensor protein specifically binds to a photocleavable NPOM-DNA adduct, and this recognition is abolished upon photo-cleavage of NPOM.![]()
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Affiliation(s)
- Amirrasoul Tavakoli
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
| | - Debamita Paul
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
| | - Hong Mu
- Department of Biology, New York University, New York, NY 10003, USA
| | - Jagannath Kuchlyan
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
| | - Saroj Baral
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Anjum Ansari
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Suse Broyde
- Department of Biology, New York University, New York, NY 10003, USA
| | - Jung-Hyun Min
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
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4
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Paul D, Mu H, Tavakoli A, Dai Q, Chen X, Chakraborty S, He C, Ansari A, Broyde S, Min JH. Tethering-facilitated DNA 'opening' and complementary roles of β-hairpin motifs in the Rad4/XPC DNA damage sensor protein. Nucleic Acids Res 2020; 48:12348-12364. [PMID: 33119737 PMCID: PMC7708039 DOI: 10.1093/nar/gkaa909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/28/2020] [Accepted: 10/02/2020] [Indexed: 01/01/2023] Open
Abstract
XPC/Rad4 initiates eukaryotic nucleotide excision repair on structurally diverse helix-destabilizing/distorting DNA lesions by selectively 'opening' these sites while rapidly diffusing along undamaged DNA. Previous structural studies showed that Rad4, when tethered to DNA, could also open undamaged DNA, suggesting a 'kinetic gating' mechanism whereby lesion discrimination relied on efficient opening versus diffusion. However, solution studies in support of such a mechanism were lacking and how 'opening' is brought about remained unclear. Here, we present crystal structures and fluorescence-based conformational analyses on tethered complexes, showing that Rad4 can indeed 'open' undamaged DNA in solution and that such 'opening' can largely occur without one or the other of the β-hairpin motifs in the BHD2 or BHD3 domains. Notably, the Rad4-bound 'open' DNA adopts multiple conformations in solution notwithstanding the DNA's original structure or the β-hairpins. Molecular dynamics simulations reveal compensatory roles of the β-hairpins, which may render robustness in dealing with and opening diverse lesions. Our study showcases how fluorescence-based studies can be used to obtain information complementary to ensemble structural studies. The tethering-facilitated DNA 'opening' of undamaged sites and the dynamic nature of 'open' DNA may shed light on how the protein functions within and beyond nucleotide excision repair in cells.
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Affiliation(s)
- Debamita Paul
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, USA
| | - Hong Mu
- Department of Biology, New York University, New York, NY 10003, USA
| | - Amirrasoul Tavakoli
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, USA
| | - Qing Dai
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
| | - Xuejing Chen
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Sagnik Chakraborty
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Chuan He
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
- Department of Biochemistry and Molecular Biology, Howard Hughes Medical Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Anjum Ansari
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Suse Broyde
- Department of Biology, New York University, New York, NY 10003, USA
| | - Jung-Hyun Min
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, USA
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5
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Chakraborty S, Steinbach PJ, Paul D, Mu H, Broyde S, Min JH, Ansari A. Enhanced spontaneous DNA twisting/bending fluctuations unveiled by fluorescence lifetime distributions promote mismatch recognition by the Rad4 nucleotide excision repair complex. Nucleic Acids Res 2019; 46:1240-1255. [PMID: 29267981 PMCID: PMC5815138 DOI: 10.1093/nar/gkx1216] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 12/12/2017] [Indexed: 12/15/2022] Open
Abstract
Rad4/XPC recognizes diverse DNA lesions including ultraviolet-photolesions and carcinogen-DNA adducts, initiating nucleotide excision repair. Studies have suggested that Rad4/XPC senses lesion-induced helix-destabilization to flip out nucleotides from damaged DNA sites. However, characterizing how DNA deformability and/or distortions impact recognition has been challenging. Here, using fluorescence lifetime measurements empowered by a maximum entropy algorithm, we mapped the conformational heterogeneities of artificially destabilized mismatched DNA substrates of varying Rad4-binding specificities. The conformational distributions, as probed by FRET between a cytosine-analog pair exquisitely sensitive to DNA twisting/bending, reveal a direct connection between intrinsic DNA deformability and Rad4 recognition. High-specificity CCC/CCC mismatch, free in solution, sampled a strikingly broad range of conformations from B-DNA-like to highly distorted conformations that resembled those observed with Rad4 bound; the extent of these distortions increased with bound Rad4 and with temperature. Conversely, the non-specific TAT/TAT mismatch had a homogeneous, B-DNA-like conformation. Molecular dynamics simulations also revealed a wide distribution of conformations for CCC/CCC, complementing experimental findings. We propose that intrinsic deformability promotes Rad4 damage recognition, perhaps by stalling a diffusing protein and/or facilitating ‘conformational capture’ of pre-distorted damaged sites. Surprisingly, even mismatched DNA specifically bound to Rad4 remains highly dynamic, a feature that may reflect the versatility of Rad4/XPC to recognize many structurally dissimilar lesions.
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Affiliation(s)
- Sagnik Chakraborty
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Peter J Steinbach
- Center for Molecular Modeling, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, USA
| | - Debamita Paul
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Hong Mu
- Department of Biology, New York University, New York, NY 10003, USA
| | - Suse Broyde
- Department of Biology, New York University, New York, NY 10003, USA
| | - Jung-Hyun Min
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Anjum Ansari
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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6
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Hikida Y, Kimoto M, Hirao I, Yokoyama S. Crystal structure of Deep Vent DNA polymerase. Biochem Biophys Res Commun 2017; 483:52-57. [PMID: 28063932 DOI: 10.1016/j.bbrc.2017.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 01/07/2023]
Abstract
DNA polymerases are useful tools in various biochemical experiments. We have focused on the DNA polymerases involved in DNA replication including the unnatural base pair between 7-(2-thienyl)imidazo[4,5-b]pyridine (Ds) and 2-nitro-4-propynylpyrrole (Px). Many reports have described the different combinations between unnatural base pairs and DNA polymerases. As an example, for the replication of the Ds-Px pair, Deep Vent DNA polymerase exhibits high efficiency and fidelity, but Taq DNA polymerase shows much lower efficiency and fidelity. In the present study, we determined the crystal structure of Deep Vent DNA polymerase in the apo form at 2.5 Å resolution. Using this structure, we constructed structural models of Deep Vent DNA polymerase complexes with DNA containing an unnatural or natural base in the replication position. The models revealed that the unnatural Ds base in the template-strand DNA clashes with the side-chain oxygen of Thr664 in Taq DNA polymerase, but not in Deep Vent DNA polymerase.
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Affiliation(s)
- Yasushi Hikida
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
| | - Michiko Kimoto
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #04-01, 138669, Singapore
| | - Ichiro Hirao
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, #04-01, 138669, Singapore.
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan; Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
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7
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Reif MM, Oostenbrink C. Molecular dynamics simulation of configurational ensembles compatible with experimental FRET efficiency data through a restraint on instantaneous FRET efficiencies. J Comput Chem 2014; 35:2319-32. [PMID: 25338770 DOI: 10.1002/jcc.23756] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 09/02/2014] [Accepted: 09/21/2014] [Indexed: 01/19/2023]
Abstract
Förster resonance energy transfer (FRET) measurements are widely used to investigate (bio)molecular interactions or/and association. FRET efficiencies, the primary data obtained from this method, give, in combination with the common assumption of isotropic chromophore orientation, detailed insight into the lengthscale of molecular phenomena. This study illustrates the application of a FRET efficiency restraint during classical atomistic molecular dynamics simulations of a mutant mastoparan X peptide in either water or 7 M aqueous urea. The restraint forces acting on the donor and acceptor chromophores ensure that the sampled peptide configurational ensemble satisfies the experimental primary data by modifying interchromophore separation and chromophore transition dipole moment orientations. By means of a conformational cluster analysis, it is seen that indeed different configurational ensembles may be sampled without and with application of the restraint. In particular, while the FRET efficiency and interchromophore distances monitored in an unrestrained simulation may differ from the experimentally-determined values, they can be brought in agreement with experimental data through usage of the FRET efficiency restraining potential. Furthermore, the present results suggest that the assumption of isotropic chromophore orientation is not always justified. The FRET efficiency restraint allows the generation of configurational ensembles that may not be accessible with unrestrained simulations, and thereby supports a meaningful interpretation of experimental FRET results in terms of the underlying molecular degrees of freedom. Thus, it offers an additional tool to connect the realms of computer and wet-lab experimentation.
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Affiliation(s)
- Maria M Reif
- Department of Material Sciences and Process Engineering, Institute for Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Vienna
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Reha-Krantz LJ, Woodgate S, Goodman MF. Engineering processive DNA polymerases with maximum benefit at minimum cost. Front Microbiol 2014; 5:380. [PMID: 25136334 PMCID: PMC4120765 DOI: 10.3389/fmicb.2014.00380] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/07/2014] [Indexed: 11/25/2022] Open
Abstract
DNA polymerases need to be engineered to achieve optimal performance for biotechnological applications, which often require high fidelity replication when using modified nucleotides and when replicating difficult DNA sequences. These tasks are achieved for the bacteriophage T4 DNA polymerase by replacing leucine with methionine in the highly conserved Motif A sequence (L412M). The costs are minimal. Although base substitution errors increase moderately, accuracy is maintained for templates with mono- and dinucleotide repeats while replication efficiency is enhanced. The L412M substitution increases intrinsic processivity and addition of phage T4 clamp and single-stranded DNA binding proteins further enhance the ability of the phage T4 L412M-DNA polymerase to replicate all types of difficult DNA sequences. Increased pyrophosphorolysis is a drawback of increased processivity, but pyrophosphorolysis is curbed by adding an inorganic pyrophosphatase or divalent metal cations, Mn2+ or Ca2+. In the absence of pyrophosphorolysis inhibitors, the T4 L412M-DNA polymerase catalyzed sequence-dependent pyrophosphorolysis under DNA sequencing conditions. The sequence specificity of the pyrophosphorolysis reaction provides insights into how the T4 DNA polymerase switches between nucleotide incorporation, pyrophosphorolysis and proofreading pathways. The L-to-M substitution was also tested in the yeast DNA polymerases delta and alpha. Because the mutant DNA polymerases displayed similar characteristics, we propose that amino acid substitutions in Motif A have the potential to increase processivity and to enhance performance in biotechnological applications. An underlying theme in this chapter is the use of genetic methods to identify mutant DNA polymerases with potential for use in current and future biotechnological applications.
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Affiliation(s)
- Linda J Reha-Krantz
- Department of Biological Sciences, University of Alberta Edmonton, AB, Canada
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Abstract
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This review will summarize our structural
and kinetic studies of
RB69 DNA polymerase (RB69pol) as well as selected variants of the
wild-type enzyme that were undertaken to obtain a deeper understanding
of the exquisitely high fidelity of B family replicative DNA polymerases.
We discuss how the structures of the various RB69pol ternary complexes
can be used to rationalize the results obtained from pre-steady-state
kinetic assays. Our main findings can be summarized as follows. (i)
Interbase hydrogen bond interactions can increase catalytic efficiency
by 5000-fold; meanwhile, base selectivity is not solely determined
by the number of hydrogen bonds between the incoming dNTP and the
templating base. (ii) Minor-groove hydrogen bond interactions at positions n – 1 and n – 2 of the primer
strand and position n – 1 of the template
strand in RB69pol ternary complexes are essential for efficient primer
extension and base selectivity. (iii) Partial charge interactions
among the incoming dNTP, the penultimate base pair, and the hydration
shell surrounding the incoming dNTP modulate nucleotide insertion
efficiency and base selectivity. (iv) Steric clashes between mismatched
incoming dNTPs and templating bases with amino acid side chains in
the nascent base pair binding pocket (NBP) as well as weak interactions
and large gaps between the incoming dNTPs and the templating base
are some of the reasons that incorrect dNTPs are incorporated so inefficiently
by wild-type RB69pol. In addition, we developed a tC°–tCnitro Förster resonance energy transfer assay to monitor
partitioning of the primer terminus between the polymerase and exonuclease
subdomains.
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Affiliation(s)
- Shuangluo Xia
- Department of Molecular Biophysics and Biochemistry, Yale University , New Haven, Connecticut 06520-8024, United States
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