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H, Elliot MA. Multifactorial genetic control and magnesium levels govern the production of a Streptomyces antibiotic with unusual cell density dependence. mSystems 2024; 9:e0136823. [PMID: 38493407 PMCID: PMC11019849 DOI: 10.1128/msystems.01368-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/15/2024] [Indexed: 03/18/2024] Open
Abstract
Streptomyces bacteria are renowned both for their antibiotic production capabilities and for their cryptic metabolic potential. Their metabolic repertoire is subject to stringent genetic control, with many of the associated biosynthetic gene clusters being repressed by the conserved nucleoid-associated protein Lsr2. In an effort to stimulate new antibiotic production in wild Streptomyces isolates, we leveraged the activity of an Lsr2 knockdown construct and successfully enhanced antibiotic production in the wild Streptomyces isolate WAC07094. We determined that this new activity stemmed from increased levels of the angucycline-like family member saquayamycin. Saquayamycin has both antibiotic and anti-cancer activities, and intriguingly, beyond Lsr2-mediated repression, we found saquayamycin production was also suppressed at high density on solid or in liquid growth media; its levels were greatest in low-density cultures. This density-dependent control was exerted at the level of the cluster-situated regulatory gene sqnR and was mediated in part through the activity of the PhoRP two-component regulatory system, where deleting phoRP led to both constitutive antibiotic production and sqnR expression. This suggests that PhoP functions to repress the expression of sqnR at high cell density. We further discovered that magnesium supplementation could alleviate this density dependence, although its action was independent of PhoP. Finally, we revealed that the nitrogen-responsive regulators GlnR and AfsQ1 could relieve the repression exerted by Lsr2 and PhoP. Intriguingly, we found that this low density-dependent production of saquayamycin was not unique to WAC07094; saquayamycin production by another wild isolate also exhibited low-density activation, suggesting that this spatial control may serve an important ecological function in their native environments.IMPORTANCEStreptomyces specialized metabolic gene clusters are subject to complex regulation, and their products are frequently not observed under standard laboratory growth conditions. For the wild Streptomyces isolate WAC07094, production of the angucycline-family compound saquayamycin is subject to a unique constellation of control factors. Notably, it is produced primarily at low cell density, in contrast to the high cell density production typical of most antibiotics. This unusual density dependence is conserved in other saquayamycin producers and is driven by the pathway-specific regulator SqnR, whose expression is influenced by both nutritional and genetic elements. Collectively, this work provides new insights into an intricate regulatory system governing antibiotic production and indicates there may be benefits to including low-density cultures in antibiotic screening platforms.
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Affiliation(s)
- Hindra
- Institute of Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Marie A. Elliot
- Institute of Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Ontario, Canada
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2
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Liu J, Zhou Z, Hou M, Xia X, Liu Y, Zhao Z, Wu Y, Deng Y, Zhang Y, He F, Xu Y, Zhu X. Capturing cerium ions via hydrogel microspheres promotes vascularization for bone regeneration. Mater Today Bio 2024; 25:100956. [PMID: 38322657 PMCID: PMC10844749 DOI: 10.1016/j.mtbio.2024.100956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/27/2023] [Accepted: 01/15/2024] [Indexed: 02/08/2024] Open
Abstract
The rational design of multifunctional biomaterials with hierarchical porous structure and on-demand biological activity is of great consequence for bone tissue engineering (BTE) in the contemporary world. The advanced combination of trace element cerium ions (Ce3+) with bone repair materials makes the composite material capable of promoting angiogenesis and enhancing osteoblast activity. Herein, a living and phosphorylated injectable porous hydrogel microsphere (P-GelMA-Ce@BMSCs) is constructed by microfluidic technology and coordination reaction with metal ion ligands while loaded with exogenous BMSCs. Exogenous stem cells can adhere to and proliferate on hydrogel microspheres, thus promoting cell-extracellular matrix (ECM) and cell-cell interactions. The active ingredient Ce3+ promotes the proliferation, osteogenic differentiation of rat BMSCs, and angiogenesis of endotheliocytes by promoting mineral deposition, osteogenic gene expression, and VEGF secretion. The enhancement of osteogenesis and improvement of angiogenesis of the P-GelMA-Ce scaffold is mainly associated with the activation of the Wnt/β-catenin pathway. This study could provide novel and meaningful insights for treating bone defects with biofunctional materials on the basis of metal ions.
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Affiliation(s)
- Junlin Liu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Zhangzhe Zhou
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Mingzhuang Hou
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Xiaowei Xia
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Yang Liu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Zhijian Zhao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Yubin Wu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Yaoge Deng
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Yijian Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Fan He
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Yong Xu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
| | - Xuesong Zhu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China
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3
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Velasquez N, B Nunes F, Travnikova O, Ismail I, Guillemin R, Martins JB, Céolin D, Journel L, Fillaud L, Koulentianos D, Kamal C, Püttner R, Piancastelli MN, Simon M, Odelius M, Iannuzzi M, Marchenko T. X-ray induced ultrafast charge transfer in thiophene-based conjugated polymers controlled by core-hole clock spectroscopy. Phys Chem Chem Phys 2024; 26:1234-1244. [PMID: 38099819 DOI: 10.1039/d3cp04303g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
We explore ultrafast charge transfer (CT) resonantly induced by hard X-ray radiation in organic thiophene-based polymers at the sulfur K-edge. A combination of core-hole clock spectroscopy with real-time propagation time-dependent density functional theory simulations gives an insight into the electron dynamics underlying the CT process. Our method provides control over CT by a selective excitation of a specific resonance in the sulfur atom with monochromatic X-ray radiation. Our combined experimental and theoretical investigation establishes that the dominant mechanism of CT in polymer powders and films consists of electron delocalisation along the polymer chain occurring on the low-femtosecond time scale.
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Affiliation(s)
- Nicolas Velasquez
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
| | - Fernanda B Nunes
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland.
| | - Oksana Travnikova
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Iyas Ismail
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Renaud Guillemin
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Jessica B Martins
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
| | - Denis Céolin
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Loïc Journel
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Laure Fillaud
- Sorbonne Université, CNRS, Laboratoire Interfaces et Systèmes Electrochimiques, LISE, F-75005 Paris Cedex 05, France
| | - Dimitris Koulentianos
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
| | - Chinnathambi Kamal
- Theory and Simulations Laboratory, TCPS, Raja Ramanna Centre for Advanced Technology, Indore 452013, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, Maharashtra 400094, India
| | - Ralph Püttner
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Maria Novella Piancastelli
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
| | - Marc Simon
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Michael Odelius
- Department of Physics, Stockholm University, AlbaNova University Center, 10691 Stockholm, Sweden
| | - Marcella Iannuzzi
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland.
| | - Tatiana Marchenko
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris Cedex 05, France.
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
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4
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Collette D, Dunlap D, Finzi L. Macromolecular Crowding and DNA: Bridging the Gap between In Vitro and In Vivo. Int J Mol Sci 2023; 24:17502. [PMID: 38139331 PMCID: PMC10744201 DOI: 10.3390/ijms242417502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
The cellular environment is highly crowded, with up to 40% of the volume fraction of the cell occupied by various macromolecules. Most laboratory experiments take place in dilute buffer solutions; by adding various synthetic or organic macromolecules, researchers have begun to bridge the gap between in vitro and in vivo measurements. This is a review of the reported effects of macromolecular crowding on the compaction and extension of DNA, the effect of macromolecular crowding on DNA kinetics, and protein-DNA interactions. Theoretical models related to macromolecular crowding and DNA are briefly reviewed. Gaps in the literature, including the use of biologically relevant crowders, simultaneous use of multi-sized crowders, empirical connections between macromolecular crowding and liquid-liquid phase separation of nucleic materials are discussed.
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Affiliation(s)
| | | | - Laura Finzi
- Department of Physics, College of Arts & Sciences, Emory University, Atlanta, GA 30322, USA; (D.C.); (D.D.)
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5
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Lelyveld VS, Fang Z, Szostak JW. Trivalent rare earth metal cofactors confer rapid NP-DNA polymerase activity. Science 2023; 382:423-429. [PMID: 37883544 PMCID: PMC10886449 DOI: 10.1126/science.adh5339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023]
Abstract
A DNA polymerase with a single mutation and a divalent calcium cofactor catalyzes the synthesis of unnatural N3'→P5' phosphoramidate (NP) bonds to form NP-DNA. However, this template-directed phosphoryl transfer activity remains orders of magnitude slower than native phosphodiester synthesis. Here, we used time-resolved x-ray crystallography to show that NP-DNA synthesis proceeds with a single detectable calcium ion in the active site. Using insights from isotopic and elemental effects, we propose that one-metal-ion electrophilic substrate activation is inferior to the native two-metal-ion mechanism. We found that this deficiency in divalent activation could be ameliorated by trivalent rare earth and post-transition metal cations, substantially enhancing NP-DNA synthesis. Scandium(III), in particular, confers highly specific NP activity with kinetics enhanced by more than 100-fold over calcium(II), yielding NP-DNA strands up to 100 nucleotides in length.
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Affiliation(s)
- Victor S Lelyveld
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Ziyuan Fang
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | - Jack W Szostak
- Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL 60637, USA
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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6
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Randhawa K, Jahani-Asl A. CLIC1 regulation of cancer stem cells in glioblastoma. CURRENT TOPICS IN MEMBRANES 2023; 92:99-123. [PMID: 38007271 DOI: 10.1016/bs.ctm.2023.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Chloride intracellular channel 1 (CLIC1) has emerged as a therapeutic target in various cancers. CLIC1 promotes cell cycle progression and cancer stem cell (CSC) self-renewal. Furthermore, CLIC1 is shown to play diverse roles in proliferation, cell volume regulation, tumour invasion, migration, and angiogenesis. In glioblastoma (GB), CLIC1 facilitates the G1/S phase transition and tightly regulates glioma stem-like cells (GSCs), a rare population of self-renewing CSCs with central roles in tumour resistance to therapy and tumour recurrence. CLIC1 is found as either a monomeric soluble protein or as a non-covalent dimeric protein that can form an ion channel. The ratio of dimeric to monomeric protein is altered in GSCs and depends on the cell redox state. Elucidating the mechanisms underlying the alterations in CLIC1 expression and structural transitions will further our understanding of its role in GSC biology. This review will highlight the role of CLIC1 in GSCs and its significance in facilitating different hallmarks of cancer.
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Affiliation(s)
- Kamaldeep Randhawa
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Arezu Jahani-Asl
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada; Regenerative Medicine Program and Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.
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7
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Oscorbin I, Filipenko M. Bst polymerase - a humble relative of Taq polymerase. Comput Struct Biotechnol J 2023; 21:4519-4535. [PMID: 37767105 PMCID: PMC10520511 DOI: 10.1016/j.csbj.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/31/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
DNA polymerases are a superfamily of enzymes synthesizing DNA using DNA as a template. They are essential for nucleic acid metabolism and for DNA replication and repair. Modern biotechnology and molecular diagnostics rely heavily on DNA polymerases in analyzing nucleic acids. Among a variety of discovered DNA polymerases, Bst polymerase, a large fragment of DNA polymerase I from Geobacillus stearothermophilus, is one of the most commonly used but is not as well studied as Taq polymerase. The ability of Bst polymerase to displace an upstream DNA strand during synthesis, coupled with its moderate thermal stability, has provided the basis for several isothermal DNA amplification methods, including LAMP, WGA, RCA, and many others. Bst polymerase is one of the key components defining the robustness and analytical characteristics of diagnostic test systems based on isothermal amplification. Here, we present an overview of the biochemical and structural features of Bst polymerase and provide information on its mutated analogs.
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Affiliation(s)
- Igor Oscorbin
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Maxim Filipenko
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
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8
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Lad SB, Upadhyay M, Thorat P, Nair D, Moseley GW, Srivastava S, Pradeepkumar PI, Kondabagil K. Biochemical Reconstitution of the Mimiviral Base Excision Repair Pathway. J Mol Biol 2023; 435:168188. [PMID: 37380013 DOI: 10.1016/j.jmb.2023.168188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 06/14/2023] [Accepted: 06/20/2023] [Indexed: 06/30/2023]
Abstract
Viruses are believed to be the obligate intracellular parasites that only carry genes essential for infecting and hijacking the host cell machinery. However, a recently discovered group of viruses belonging to the phylum nucleocytovirocota, also known as the nucleo-cytoplasmic large DNA viruses (NCLDVs), possess a number of genes that code for proteins predicted to be involved in metabolism, and DNA replication, and repair. In the present study, first, using proteomics of viral particles, we show that several proteins required for the completion of the DNA base excision repair (BER) pathway are packaged within the virions of Mimivirus as well as related viruses while they are absent from the virions of Marseillevirus and Kurlavirus that are NCLDVs with smaller genomes. We have thoroughly characterized three putative base excision repair enzymes from Mimivirus, a prototype NCLDV and successfully reconstituted the BER pathway using the purified recombinant proteins. The mimiviral uracil-DNA glycosylase (mvUDG) excises uracil from both ssDNA and dsDNA, a novel finding contrary to earlier studies. The putative AP-endonuclease (mvAPE) specifically cleaves at the abasic site created by the glycosylase while also exhibiting the 3'-5' exonuclease activity. The Mimivirus polymerase X protein (mvPolX) can bind to gapped DNA substrates and perform single nucleotide gap-filling followed by downstream strand displacement. Furthermore, we show that when reconstituted in vitro, mvUDG, mvAPE, and mvPolX function cohesively to repair a uracil-containing DNA predominantly by long patch BER and together, may participate in the BER pathway during the early phase of Mimivirus life-cycle.
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Affiliation(s)
- Shailesh B Lad
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India. https://twitter.com/shailesh2603
| | - Monica Upadhyay
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India; Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia. https://twitter.com/upadhyaymonica
| | - Pracheta Thorat
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
| | - Divya Nair
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
| | - Gregory W Moseley
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India. https://twitter.com/sanjeeva_IITB
| | - P I Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India. https://twitter.com/pradeepkumarpi
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India.
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9
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Deshpande S, Huo W, Shrestha R, Sparrow K, Wood JM, Evans GB, Harris LD, Kingston RL, Bulloch EMM. Galidesivir Triphosphate Promotes Stalling of Dengue-2 Virus Polymerase Immediately Prior to Incorporation. ACS Infect Dis 2023; 9:1658-1673. [PMID: 37488090 PMCID: PMC10739630 DOI: 10.1021/acsinfecdis.3c00311] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Indexed: 07/26/2023]
Abstract
Millions of people are infected by the dengue and Zika viruses each year, resulting in significant morbidity and mortality. Galidesivir is an adenosine nucleoside analog that can attenuate flavivirus replication in cell-based assays and animal models of infection. Galidesivir is converted to the triphosphorylated form by host kinases and subsequently incorporated into viral RNA by viral RNA polymerases. This has been proposed to lead to the delayed termination of RNA synthesis. Here, we report direct in vitro testing of the effects of Galidesivir triphosphate on dengue-2 and Zika virus polymerase activity. Galidesivir triphosphate was chemically synthesized, and inhibition of RNA synthesis followed using a dinucleotide-primed assay with a homopolymeric poly(U) template. Galidesivir triphosphate was equipotent against dengue-2 and Zika polymerases, with IC50 values of 42 ± 12 μM and 47 ± 5 μM, respectively, at an ATP concentration of 20 μM. RNA primer extension assays show that the dengue-2 polymerase stalls while attempting to add a Galidesivir nucleotide to the nascent RNA chain, evidenced by the accumulation of RNA products truncated immediately upstream of Galidesivir incorporation sites. Nevertheless, Galidesivir is incorporated at isolated sites with low efficiency, leading to the subsequent synthesis of full-length RNA with no evidence of delayed chain termination. The incorporation of Galidesivir at consecutive sites is strongly disfavored, highlighting the potential for modulation of inhibitory effects of nucleoside analogs by the template sequence. Our results suggest that attenuation of dengue replication by Galidesivir may not derive from the early termination of RNA synthesis following Galidesivir incorporation.
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Affiliation(s)
- Sandesh Deshpande
- School
of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Wenjuan Huo
- School
of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Rinu Shrestha
- Ferrier
Research Institute, Victoria University of Wellington, 69 Gracefield Rd, Lower Hutt 5010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
| | - Kevin Sparrow
- Ferrier
Research Institute, Victoria University of Wellington, 69 Gracefield Rd, Lower Hutt 5010, New Zealand
| | - James M. Wood
- Ferrier
Research Institute, Victoria University of Wellington, 69 Gracefield Rd, Lower Hutt 5010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
| | - Gary B. Evans
- Ferrier
Research Institute, Victoria University of Wellington, 69 Gracefield Rd, Lower Hutt 5010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
| | - Lawrence D. Harris
- Ferrier
Research Institute, Victoria University of Wellington, 69 Gracefield Rd, Lower Hutt 5010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
| | - Richard L. Kingston
- School
of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
| | - Esther M. M. Bulloch
- School
of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1010, New Zealand
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10
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Bosch-Rué È, Díez-Tercero L, Buitrago JO, Castro E, Pérez RA. Angiogenic and immunomodulation role of ions for initial stages of bone tissue regeneration. Acta Biomater 2023; 166:14-41. [PMID: 37302735 DOI: 10.1016/j.actbio.2023.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/10/2023] [Accepted: 06/06/2023] [Indexed: 06/13/2023]
Abstract
It is widely known that bone has intrinsic capacity to self-regenerate after injury. However, the physiological regeneration process can be impaired when there is an extensive damage. One of the main reasons is due to the inability to establish a new vascular network that ensures oxygen and nutrient diffusion, leading to a necrotic core and non-junction of bone. Initially, bone tissue engineering (BTE) emerged to use inert biomaterials to just fill bone defects, but it eventually evolved to mimic bone extracellular matrix and even stimulate bone physiological regeneration process. In this regard, the stimulation of osteogenesis has gained a lot of attention especially in the proper stimulation of angiogenesis, being critical to achieve a successful osteogenesis for bone regeneration. Besides, the immunomodulation of a pro-inflammatory environment towards an anti-inflammatory one upon scaffold implantation has been considered another key process for a proper tissue restoration. To stimulate these phases, growth factors and cytokines have been extensively used. Nonetheless, they present some drawbacks such as low stability and safety concerns. Alternatively, the use of inorganic ions has attracted higher attention due to their higher stability and therapeutic effects with low side effects. This review will first focus in giving fundamental aspects of initial bone regeneration phases, focusing mainly on inflammatory and angiogenic ones. Then, it will describe the role of different inorganic ions in modulating the immune response upon biomaterial implantation towards a restorative environment and their ability to stimulate angiogenic response for a proper scaffold vascularization and successful bone tissue restoration. STATEMENT OF SIGNIFICANCE: The impairment of bone tissue regeneration when there is excessive damage has led to different tissue engineered strategies to promote bone healing. Significant importance has been given in the immunomodulation towards an anti-inflammatory environment together with proper angiogenesis stimulation in order to achieve successful bone regeneration rather than stimulating only the osteogenic differentiation. Ions have been considered potential candidates to stimulate these events due to their high stability and therapeutic effects with low side effects compared to growth factors. However, up to now, no review has been published assembling all this information together, describing individual effects of ions on immunomodulation and angiogenic stimulation, as well as their multifunctionality or synergistic effects when combined together.
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Affiliation(s)
- Èlia Bosch-Rué
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, s/n, Sant Cugat del Vallès, Barcelona 08195, Spain; Basic Sciences Department, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Barcelona 08195, Spain
| | - Leire Díez-Tercero
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, s/n, Sant Cugat del Vallès, Barcelona 08195, Spain; Basic Sciences Department, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Barcelona 08195, Spain
| | - Jenifer Olmos Buitrago
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, s/n, Sant Cugat del Vallès, Barcelona 08195, Spain; Basic Sciences Department, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Barcelona 08195, Spain
| | - Emilio Castro
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, s/n, Sant Cugat del Vallès, Barcelona 08195, Spain; Basic Sciences Department, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Barcelona 08195, Spain
| | - Roman A Pérez
- Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Josep Trueta, s/n, Sant Cugat del Vallès, Barcelona 08195, Spain; Basic Sciences Department, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Barcelona 08195, Spain.
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11
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Haberland VMM, Magin S, Iliakis G, Hartwig A. Impact of Manganese and Chromate on Specific DNA Double-Strand Break Repair Pathways. Int J Mol Sci 2023; 24:10392. [PMID: 37373538 DOI: 10.3390/ijms241210392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Manganese is an essential trace element; nevertheless, on conditions of overload, it becomes toxic, with neurotoxicity being the main concern. Chromate is a well-known human carcinogen. The underlying mechanisms seem to be oxidative stress as well as direct DNA damage in the case of chromate, but also interactions with DNA repair systems in both cases. However, the impact of manganese and chromate on DNA double-strand break (DSB) repair pathways is largely unknown. In the present study, we examined the induction of DSB as well as the effect on specific DNA DSB repair mechanisms, namely homologous recombination (HR), non-homologous end joining (NHEJ), single strand annealing (SSA), and microhomology-mediated end joining (MMEJ). We applied DSB repair pathway-specific reporter cell lines, pulsed field gel electrophoresis as well as gene expression analysis, and investigated the binding of specific DNA repair proteins via immunoflourescence. While manganese did not seem to induce DNA DSB and had no impact on NHEJ and MMEJ, HR and SSA were inhibited. In the case of chromate, the induction of DSB was further supported. Regarding DSB repair, no inhibition was seen in the case of NHEJ and SSA, but HR was diminished and MMEJ was activated in a pronounced manner. The results indicate a specific inhibition of error-free HR by manganese and chromate, with a shift towards error-prone DSB repair mechanisms in both cases. These observations suggest the induction of genomic instability and may explain the microsatellite instability involved in chromate-induced carcinogenicity.
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Affiliation(s)
- Vivien M M Haberland
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Simon Magin
- Institute of Medical Radiation Biology, Medical School, University of Duisburg-Essen, 45122 Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, Medical School, University of Duisburg-Essen, 45122 Essen, Germany
| | - Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
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12
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Zhu S, Yang B, Wang Z, Liu Y. Augmented dissemination of antibiotic resistance elicited by non-antibiotic factors. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115124. [PMID: 37327521 DOI: 10.1016/j.ecoenv.2023.115124] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/24/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
The emergence and rapid spread of antibiotic resistance seriously compromise the clinical efficacy of current antibiotic therapies, representing a serious public health threat worldwide. Generally, drug-susceptible bacteria can acquire antibiotic resistance through genetic mutation or gene transfer, among which horizontal gene transfer (HGT) plays a dominant role. It is widely acknowledged that the sub-inhibitory concentrations of antibiotics are the key drivers in promoting the transmission of antibiotic resistance. However, accumulating evidence in recent years has shown that in addition to antibiotics, non-antibiotics can also accelerate the horizontal transfer of antibiotic resistance genes (ARGs). Nevertheless, the roles and potential mechanisms of non-antibiotic factors in the transmission of ARGs remain largely underestimated. In this review, we depict the four pathways of HGT and their differences, including conjugation, transformation, transduction and vesiduction. We summarize non-antibiotic factors accounting for the enhanced horizontal transfer of ARGs and their underlying molecular mechanisms. Finally, we discuss the limitations and implications of current studies.
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Affiliation(s)
- Shuyao Zhu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Bingqing Yang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhiqiang Wang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China.
| | - Yuan Liu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China; Institute of Comparative Medicine, Yangzhou University, Yangzhou, Jiangsu, China.
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13
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Schmaltz LF, Koag MC, Kou Y, Zhang L, Lee S. Genotoxic effects of the major alkylation damage N7-methylguanine and methyl formamidopyrimidine. Biochem J 2023; 480:573-585. [PMID: 37078496 PMCID: PMC11061863 DOI: 10.1042/bcj20220460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 03/29/2023] [Accepted: 04/19/2023] [Indexed: 04/21/2023]
Abstract
Various alkylating agents are known to preferentially modify guanine in DNA, resulting in the formation of N7-alkylguanine (N7-alkylG) and the imidazole ring opened alkyl-formamidopyrimidine (alkyl-FapyG) lesions. Evaluating the mutagenic effects of N7-alkylG has been challenging due to the instability of the positively charged N7-alkylG. To address this issue, we developed a 2'-fluorine-mediated transition-state destabilization approach, which stabilizes N7-alkylG and prevents spontaneous depurination. We also developed a postsynthetic conversion of 2'-F-N7-alkylG DNA into 2'-F-alkyl-FapyG DNA. Using these methods, we incorporated site-specific N7-methylG and methyl-FapyG into pSP189 plasmid and determined their mutagenic properties in bacterial cells using the supF-based colony screening assay. The mutation frequency of N7-methylG was found to be less than 0.5%. Our crystal structure analysis revealed that N7-methylation did not significantly alter base pairing properties, as evidenced by a correct base pairing between 2'-F-N7-methylG and dCTP in Dpo4 polymerase catalytic site. In contrast, the mutation frequency of methyl-FapyG was 6.3%, highlighting the mutagenic nature of this secondary lesion. Interestingly, all mutations arising from methyl-FapyG in the 5'-GGT(methyl-FapyG)G-3' context were single nucleotide deletions at the 5'-G of the lesion. Overall, our results demonstrate that 2'-fluorination technology is a useful tool for studying the chemically labile N7-alkylG and alkyl-FapyG lesions.
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Affiliation(s)
- Lillian F Schmaltz
- From the Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
| | - Myong-Chul Koag
- From the Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
| | - Yi Kou
- From the Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
| | - Louis Zhang
- From the Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
| | - Seongmin Lee
- From the Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
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14
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Carter ZI, Jacobs RQ, Schneider DA, Lucius AL. Transient-State Kinetic Analysis of the RNA Polymerase II Nucleotide Incorporation Mechanism. Biochemistry 2023; 62:95-108. [PMID: 36525636 PMCID: PMC10069233 DOI: 10.1021/acs.biochem.2c00608] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Eukaryotic RNA polymerase II (Pol II) is an essential enzyme that lies at the core of eukaryotic biology. Due to its pivotal role in gene expression, Pol II has been subjected to a substantial number of investigations. We aim to further our understanding of Pol II nucleotide incorporation by utilizing transient-state kinetic techniques to examine Pol II single nucleotide addition on the millisecond time scale. We analyzed Saccharomyces cerevisiae Pol II incorporation of ATP or an ATP analog, Sp-ATP-α-S. Here we have measured the rate constants governing individual steps of the Pol II transcription cycle in the presence of ATP or Sp-ATP-α-S. These results suggest that Pol II catalyzes nucleotide incorporation by binding the next cognate nucleotide and immediately catalyzes bond formation and bond formation is either followed by a conformational change or pyrophosphate release. By comparing our previously published RNA polymerase I (Pol I) and Pol I lacking the A12 subunit (Pol I ΔA12) results that we collected under the same conditions with the identical technique, we show that Pol II and Pol I ΔA12 exhibit similar nucleotide addition mechanisms. This observation indicates that removal of the A12 subunit from Pol I results in a Pol II like enzyme. Taken together, these data further our collective understanding of Pol II's nucleotide incorporation mechanism and the evolutionary divergence of RNA polymerases across the three domains of life.
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Affiliation(s)
- Zachariah I Carter
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama35233, United States
| | - Ruth Q Jacobs
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama35233, United States
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama35233, United States
| | - Aaron L Lucius
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama35233, United States
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15
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Aggarwal T, Hansen WA, Hong J, Ganguly A, York DM, Khare SD, Izgu EC. Introducing a New Bond-Forming Activity in an Archaeal DNA Polymerase by Structure-Guided Enzyme Redesign. ACS Chem Biol 2022; 17:1924-1936. [PMID: 35776893 DOI: 10.1021/acschembio.2c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA polymerases have evolved to feature a highly conserved activity across the tree of life: formation of, without exception, internucleotidyl O-P linkages. Can this linkage selectivity be overcome by design to produce xenonucleic acids? Here, we report that the structure-guided redesign of an archaeal DNA polymerase, 9°N, exhibits a new activity undetectable in the wild-type enzyme: catalyzing the formation of internucleotidyl N-P linkages using 3'-NH2-ddNTPs. Replacing a metal-binding aspartate in the 9°N active site with asparagine was key to the emergence of this unnatural enzyme activity. MD simulations provided insights into how a single substitution enhances the productive positioning of a 3'-amino nucleophile in the active site. Further remodeling of the protein-nucleic acid interface in the finger subdomain yielded a quadruple-mutant variant (9°N-NRQS) displaying DNA-dependent NP-DNA polymerase activity. In addition, the engineered promiscuity of 9°N-NRQS was leveraged for one-pot synthesis of DNA─NP-DNA copolymers. This work sheds light on the molecular basis of substrate fidelity and latent promiscuity in enzymes.
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Affiliation(s)
- Tushar Aggarwal
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - William A Hansen
- Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Jonathan Hong
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Abir Ganguly
- Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Laboratory for Biomolecular Simulation Research, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Darrin M York
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Laboratory for Biomolecular Simulation Research, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Sagar D Khare
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Institute for Quantitative Biomedicine, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Enver Cagri Izgu
- Department of Chemistry and Chemical Biology, Rutgers University, New Brunswick, New Jersey 08854, United States.,Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey 08901, United States.,Rutgers Center for Lipid Research and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901, United States
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16
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Kim G, Lee DS, Eccles H, Kim SM, Cho HU, Park JM. Selective strontium adsorption using synthesized sodium titanate in aqueous solution. RSC Adv 2022; 12:18936-18944. [PMID: 35873321 PMCID: PMC9240817 DOI: 10.1039/d2ra02494b] [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: 04/18/2022] [Accepted: 06/14/2022] [Indexed: 11/25/2022] Open
Abstract
Amorphous sodium titanates were synthesized using a mid-temperature sol–gel method for evaluation as selective adsorbents of strontium in the presence of cesium or metal cations (Al3+, Mg2+, Ca2+, and Mn2+) from aqueous solution. Synthesized sodium titanate showed high adsorption capacity and selectivity for strontium. The maximum adsorption capacity of strontium by sodium titanate was 193.93 mg g−1 in aqueous solution containing an initial concentration of 5 mM (438.60 mg L−1) strontium and 5 mM (666.67 mg L−1) cesium, and this sodium titanate removed 99.9% of the strontium and 40.67% of cesium from an aqueous solution that had an initial concentration of 1.14 mM (100 mg L−1) strontium and 0.75 mM (100 mg L−1) cesium. Strontium adsorption by synthesized sodium titanate followed pseudo-second-order kinetics and a generalized Langmuir isotherm model, and reached an adsorption equilibrium within 1 h with high adsorption capacity at equilibrium. Adsorbed strontium onto synthesized sodium titanate showed the behavior of forming a strontium titanate structure with a titanate frame via surface precipitation. Amorphous sodium titanates were synthesized using a mid-temperature sol–gel method for evaluation as selective adsorbents of strontium in the presence of cesium or metal cations (Al3+, Mg2+, Ca2+, and Mn2+) from aqueous solution.![]()
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Affiliation(s)
- Gyuhyeon Kim
- Division of Advanced Nuclear Engineering, Pohang University of Science and Technology Pohang 37673 Republic of Korea
| | - Dae Sung Lee
- Department of Environmental Engineering, Kyungpook National University 80 Daehak-ro, Buk-gu Daegu 41566 Republic of Korea
| | - Harry Eccles
- School of Computing, Engineering and Physical Sciences, University of Central Lancashire Preston PR1 2HE UK
| | - Su Min Kim
- Department of Marine Environmental Engineering, Gyeongsang National University Tongyeong 53064 Republic of Korea
| | - Hyun Uk Cho
- Department of Marine Environmental Engineering, Gyeongsang National University Tongyeong 53064 Republic of Korea
| | - Jong Moon Park
- Division of Advanced Nuclear Engineering, Pohang University of Science and Technology Pohang 37673 Republic of Korea.,School of Environmental Science and Engineering, Pohang University of Science and Technology Pohang 37673 Republic of Korea.,Department of Chemical Engineering, Pohang University of Science and Technology Pohang 37673 Republic of Korea.,School of Integrated Technology, Yonsei University (POSTECH-Yonsei Open Campus) Pohang 37673 Republic of Korea
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17
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Cressey TN, Shareef AM, Kleiner VA, Noton SL, Byrne PO, McLellan JS, Mühlberger E, Fearns R. Distinctive features of the respiratory syncytial virus priming loop compared to other non-segmented negative strand RNA viruses. PLoS Pathog 2022; 18:e1010451. [PMID: 35731802 PMCID: PMC9255747 DOI: 10.1371/journal.ppat.1010451] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 07/05/2022] [Accepted: 05/20/2022] [Indexed: 11/23/2022] Open
Abstract
De novo initiation by viral RNA-dependent RNA polymerases often requires a polymerase priming residue, located within a priming loop, to stabilize the initiating NTPs. Polymerase structures from three different non-segmented negative strand RNA virus (nsNSV) families revealed putative priming loops in different conformations, and an aromatic priming residue has been identified in the rhabdovirus polymerase. In a previous study of the respiratory syncytial virus (RSV) polymerase, we found that Tyr1276, the L protein aromatic amino acid residue that most closely aligns with the rhabdovirus priming residue, is not required for RNA synthesis but two nearby residues, Pro1261 and Trp1262, were required. In this study, we examined the roles of Pro1261 and Trp1262 in RNA synthesis initiation. Biochemical studies showed that substitution of Pro1261 inhibited RNA synthesis initiation without inhibiting back-priming, indicating a defect in initiation. Biochemical and minigenome experiments showed that the initiation defect incurred by a P1261A substitution could be rescued by factors that would be expected to increase the stability of the initiation complex, specifically increased NTP concentration, manganese, and a more efficient promoter sequence. These findings indicate that Pro1261 of the RSV L protein plays a role in initiation, most likely in stabilizing the initiation complex. However, we found that substitution of the corresponding proline residue in a filovirus polymerase had no effect on RNA synthesis initiation or elongation. These results indicate that despite similarities between the nsNSV polymerases, there are differences in the features required for RNA synthesis initiation. RSV has a significant impact on human health. It is the major cause of respiratory disease in infants and exerts a significant toll on the elderly and immunocompromised. RSV is a member of the Mononegavirales, the non-segmented, negative strand RNA viruses (nsNSVs). Like other viruses in this order, RSV encodes an RNA dependent RNA polymerase, which is responsible for transcribing and replicating the viral genome. Due to its essential role during the viral replication cycle, the polymerase is a promising candidate target for antiviral inhibitors and so a greater understanding of the mechanistic basis of its activities could aid antiviral drug development. In this study, we identified an amino acid residue within the RSV polymerase that appears to stabilize the RNA synthesis initiation complex and showed that it plays a role in both transcription and RNA replication. However, the corresponding residue in a different nsNSV polymerase does not appear to play a similar role. This work reveals a key feature of the RSV polymerase but identifies differences with the polymerases of other related viruses.
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Affiliation(s)
- Tessa N. Cressey
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
| | - Afzaal M. Shareef
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
| | - Victoria A. Kleiner
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
| | - Sarah L. Noton
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
| | - Patrick O. Byrne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, United States of America
| | - Jason S. McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, United States of America
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
| | - Rachel Fearns
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, Massachusetts, United States of America
- * E-mail:
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18
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Seevaratnam D, Ansah F, Aniweh Y, Awandare GA, Hall EAH. Analysis and validation of silica-immobilised BST polymerase in loop-mediated isothermal amplification (LAMP) for malaria diagnosis. Anal Bioanal Chem 2022; 414:6309-6326. [PMID: 35657389 PMCID: PMC9163865 DOI: 10.1007/s00216-022-04131-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/04/2022] [Accepted: 05/12/2022] [Indexed: 12/12/2022]
Abstract
Bacillus stearothermophilus large fragment (BSTLF) DNA polymerase is reported, isolated on silica via a fused R5 silica-affinity peptide and used in nucleic acid diagnostics. mCherry (mCh), included in the fusion construct, was shown as an efficient fluorescent label to follow the workflow from gene to diagnostic. The R5 immobilisation on silica from cell lysate was consistent with cooperative R5-specific binding of R52-mCh-FL-BSTLF or R52-mCh-H10-BSTLF fusion proteins followed by non-specific protein binding (including E. coli native proteins). Higher R5-binding could be achieved in the presence of phosphate, but phosphate residue reduced loop-mediated isothermal amplification (LAMP) performance, possibly blocking sites on the BSTLF for binding of β- and γ-phosphates of the dNTPs. Quantitative assessment showed that cations (Mg2+ and Mn2+) that complex the PPi product optimised enzyme activity. In malaria testing, the limit of detection depended on Plasmodium species and primer set. For example, 1000 copies of P. knowlesi 18S rRNA could be detected with the P.KNO-LAU primer set with Si-R52-mCh-FL-BSTLF , but 10 copies of P. ovale 18S rRNA could be detected with the P.OVA-HAN primer set using the same enzyme. The Si-immobilised BSTLF outperformed the commercial enzyme for four of the nine Plasmodium LAMP primer sets tested. Si-R52-mCh-FL-BSTLF production was transferred from Cambridge to Accra and set up de novo for a trial with clinical samples. Different detection limits were found, targeting the mitochondrial DNA or the 18S rRNA gene for P. falciparum. The results are discussed in comparison with qPCR and sampling protocol and show that the Si-BSTLF polymerase can be optimised to meet the WHO recommended guidelines.
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19
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Migliore R, Biver T, Barone G, Sgarlata C. Quantitative Analysis of the Interactions of Metal Complexes and Amphiphilic Systems: Calorimetric, Spectroscopic and Theoretical Aspects. Biomolecules 2022; 12:biom12030408. [PMID: 35327600 PMCID: PMC8946196 DOI: 10.3390/biom12030408] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 01/27/2023] Open
Abstract
Metals and metal-based compounds have many implications in biological systems. They are involved in cellular functions, employed in the formation of metal-based drugs and present as pollutants in aqueous systems, with toxic effects for living organisms. Amphiphilic molecules also play important roles in the above bio-related fields as models of membranes, nanocarriers for drug delivery and bioremediating agents. Despite the interest in complex systems involving both metal species and surfactant aggregates, there is still insufficient knowledge regarding the quantitative aspects at the basis of their binding interactions, which are crucial for extensive comprehension of their behavior in solution. Only a few papers have reported quantitative analyses of the thermodynamic, kinetic, speciation and binding features of metal-based compounds and amphiphilic aggregates, and no literature review has yet addressed the quantitative study of these complexes. Here, we summarize and critically discuss the recent contributions to the quantitative investigation of the interactions of metal-based systems with assemblies made of amphiphilic molecules by calorimetric, spectrophotometric and computational techniques, emphasizing the unique picture and parameters that such an analytical approach may provide, to support a deep understanding and beneficial use of these systems for several applications.
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Affiliation(s)
- Rossella Migliore
- Institute of Biomolecular Chemistry, National Research Council, Via Paolo Gaifami 18, 95126 Catania, Italy;
| | - Tarita Biver
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy;
| | - Giampaolo Barone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 17, 90128 Palermo, Italy;
| | - Carmelo Sgarlata
- Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy
- Correspondence:
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20
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Jung H, Rayala NK, Lee S. Effects of N7-Alkylguanine Conformation and Metal Cofactors on the Translesion Synthesis by Human DNA Polymerase η. Chem Res Toxicol 2022; 35:512-521. [PMID: 35239327 DOI: 10.1021/acs.chemrestox.1c00416] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Non-enzymatic alkylation on DNA often generates N7-alkyl-2'-deoxyguanosine (N7alkylG) adducts as major lesions. N7alkylG adducts significantly block replicative DNA polymerases and can be bypassed by translesion synthesis (TLS) polymerases such as polymerase η (polη). To gain insights into the bypass of N7alkylG by TLS polymerases, we conducted kinetic and structural studies of polη catalyzing across N7BnG, a genotoxic lesion generated by the carcinogenic N-nitrosobenzylmethylamine. The presence of templating N7BnG in the polη catalytic site decreased the replication fidelity by ∼9-fold, highlighting the promutagenicity of N7BnG. The catalytic efficiency for dCTP incorporation opposite N7BnG decreased ∼22-fold and ∼7-fold compared to the incorporation opposite undamaged guanine in the presence of Mg2+ and Mn2+, respectively. A crystal structure of the complexes grown with polη, templating N7BnG, incoming dCTP, and Mg2+ ions showed the lack of the incoming nucleotide and metal cofactors in the polη catalytic site. Interestingly, the templating N7BnG adopted a syn conformation, which has not been observed in the published N7alkylG structures. The preferential formation of syn-N7BnG conformation at the templating site may deter the binding of an incoming dCTP, causing the inefficient bypass by polη. In contrast, the use of Mn2+ in place of Mg2+ in co-crystallization yielded a ternary complex displaying an anti-N7BnG:dCTP base pair and catalytic metal ions, which would be a close mimic of a catalytically competent state. We conclude that certain bulky N7-alkylG lesions can slow TLS polymerase-mediated bypass by adopting a catalytically unfavorable syn conformation in the replicating base pair site.
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Affiliation(s)
- Hunmin Jung
- The Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Naveen Kumar Rayala
- The Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Seongmin Lee
- The Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712, USA
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21
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Wang J, Konigsberg WH. Two-Metal-Ion Catalysis: Inhibition of DNA Polymerase Activity by a Third Divalent Metal Ion. Front Mol Biosci 2022; 9:824794. [PMID: 35300112 PMCID: PMC8921852 DOI: 10.3389/fmolb.2022.824794] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/14/2022] [Indexed: 11/15/2022] Open
Abstract
Almost all DNA polymerases (pols) exhibit bell-shaped activity curves as a function of both pH and Mg2+ concentration. The pol activity is reduced when the pH deviates from the optimal value. When the pH is too low the concentration of a deprotonated general base (namely, the attacking 3′-hydroxyl of the 3′ terminal residue of the primer strand) is reduced exponentially. When the pH is too high the concentration of a protonated general acid (i.e., the leaving pyrophosphate group) is reduced. Similarly, the pol activity also decreases when the concentration of the divalent metal ions deviates from its optimal value: when it is too low, the binding of the two catalytic divalent metal ions required for the full activity is incomplete, and when it is too high a third divalent metal ion binds to pyrophosphate, keeping it in the replication complex longer and serving as a substrate for pyrophosphorylysis within the complex. Currently, there is a controversy about the role of the third metal ion which we will address in this review.
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22
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Abstract
B-family DNA polymerases (PolBs) of different groups are widespread in Archaea, and different PolBs often coexist in the same organism. Many of these PolB enzymes remain to be investigated. One of the main groups that is poorly characterized is PolB2, whose members occur in many archaea but are predicted to be inactivated forms of DNA polymerase. Here, Sulfolobus islandicus DNA polymerase 2 (Dpo2), a PolB2 enzyme, was expressed in its native host and purified. Characterization of the purified enzyme revealed that the polymerase possesses a robust nucleotide incorporation activity but is devoid of the 3'-5' exonuclease activity. Enzyme kinetics analyses showed that Dpo2 replicates undamaged DNA templates with high fidelity, which is consistent with its inefficient nucleotide insertion activity opposite different DNA lesions. Strikingly, the polymerase is highly efficient in extending mismatches and mispaired primer termini once a nucleotide is placed opposite a damaged site. This extender polymerase represents a novel type of prokaryotic PolB specialized for DNA damage repair in Archaea. IMPORTANCE In this work, we report that Sulfolobus islandicus Dpo2, a B-family DNA polymerase once predicted to be an inactive form, is a bona fide DNA polymerase functioning in translesion synthesis. S. islandicus Dpo2 is a member of a large group of B-family DNA polymerases (PolB2) that are present in many archaea and some bacteria, and they carry variations in well-conserved amino acids in the functional domains responsible for polymerization and proofreading. However, we found that this prokaryotic B-family DNA polymerase not only replicates undamaged DNA with high fidelity but also extends mismatch and DNA lesion-containing substrates with high efficiencies. With these data, we propose this enzyme functions as an extender polymerase, the first prokaryotic enzyme of this type. Our data also suggest this PolB2 enzyme represents a functional counterpart of the eukaryotic DNA polymerase Pol zeta, an enzyme that is devoted to DNA damage repair.
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23
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Tomić A, Tomić S. Demystifying DPP III Catalyzed Peptide Hydrolysis—Computational Study of the Complete Catalytic Cycle of Human DPP III Catalyzed Tynorphin Hydrolysis. Int J Mol Sci 2022; 23:ijms23031858. [PMID: 35163780 PMCID: PMC8836397 DOI: 10.3390/ijms23031858] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/28/2022] [Accepted: 02/03/2022] [Indexed: 12/04/2022] Open
Abstract
Dipeptidyl peptides III (DPP III) is a dual-domain zinc exopeptidase that hydrolyzes peptides of varying sequence and size. Despite attempts to elucidate and narrow down the broad substrate-specificity of DPP III, there is no explanation as to why some of them, such as tynorphin (VVYPW), the truncated form of the endogenous heptapeptide spinorphin, are the slow-reacting substrates of DPP III compared to others, such as Leu-enkephalin. Using quantum molecular mechanics calculations followed by various molecular dynamics techniques, we describe for the first time the entire catalytic cycle of human DPP III, providing theoretical insight into the inhibitory mechanism of tynorphin. The chemical step of peptide bond hydrolysis and the substrate binding to the active site of the enzyme and release of the product were described for DPP III in complex with tynorphin and Leu-enkephalin and their products. We found that tynorphin is cleaved by the same reaction mechanism determined for Leu-enkephalin. More importantly, we showed that the product stabilization and regeneration of the enzyme, but not the nucleophilic attack of the catalytic water molecule and inversion at the nitrogen atom of the cleavable peptide bond, correspond to the rate-determining steps of the overall catalytic cycle of the enzyme.
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24
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Huang XL, Chen YQ, Wen GH, Bao SS, Zheng LM. Hydrated Metal Ions as Weak Bronsted Acids Show the Promoting Effects in Proton Conduction. CrystEngComm 2022. [DOI: 10.1039/d2ce00430e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is well-known that the hydrated metal ions can act as Bronsted acids, which tend to donate protons increasing the acidic proton concentration in materials, as well as the proton...
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25
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Vaisman A, McDonald JP, Smith MR, Aspelund SL, Evans TC, Woodgate R. Identification and Characterization of Thermostable Y-Family DNA Polymerases η, ι, κ and Rev1 From a Lower Eukaryote, Thermomyces lanuginosus. Front Mol Biosci 2021; 8:778400. [PMID: 34805283 PMCID: PMC8595933 DOI: 10.3389/fmolb.2021.778400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
Y-family DNA polymerases (pols) consist of six phylogenetically separate subfamilies; two UmuC (polV) branches, DinB (pol IV, Dpo4, polκ), Rad30A/POLH (polη), and Rad30B/POLI (polι) and Rev1. Of these subfamilies, DinB orthologs are found in all three domains of life; eubacteria, archaea, and eukarya. UmuC orthologs are identified only in bacteria, whilst Rev1 and Rad30A/B orthologs are only detected in eukaryotes. Within eukaryotes, a wide array of evolutionary diversity exists. Humans possess all four Y-family pols (pols η, ι, κ, and Rev1), Schizosaccharomyces pombe has three Y-family pols (pols η, κ, and Rev1), and Saccharomyces cerevisiae only has polη and Rev1. Here, we report the cloning, expression, and biochemical characterization of the four Y-family pols from the lower eukaryotic thermophilic fungi, Thermomyces lanuginosus. Apart from the expected increased thermostability of the T. lanuginosus Y-family pols, their major biochemical properties are very similar to properties of their human counterparts. In particular, both Rad30B homologs (T. lanuginosus and human polɩ) exhibit remarkably low fidelity during DNA synthesis that is template sequence dependent. It was previously hypothesized that higher organisms had acquired this property during eukaryotic evolution, but these observations imply that polι originated earlier than previously known, suggesting a critical cellular function in both lower and higher eukaryotes.
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Affiliation(s)
- Alexandra Vaisman
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - John P McDonald
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Mallory R Smith
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Sender L Aspelund
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Thomas C Evans
- New England Biolabs Incorporated, Ipswich, MA, United States
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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26
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Chan KY, Li X, Ortega J, Gu L, Li GM. DNA polymerase θ promotes CAG•CTG repeat expansions in Huntington's disease via insertion sequences of its catalytic domain. J Biol Chem 2021; 297:101144. [PMID: 34473992 PMCID: PMC8463855 DOI: 10.1016/j.jbc.2021.101144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/04/2022] Open
Abstract
Huntington's disease (HD), a neurodegenerative disease characterized by progressive dementia, psychiatric problems, and chorea, is known to be caused by CAG repeat expansions in the HD gene HTT. However, the mechanism of this pathology is not fully understood. The translesion DNA polymerase θ (Polθ) carries a large insertion sequence in its catalytic domain, which has been shown to allow DNA loop-outs in the primer strand. As a result of high levels of oxidative DNA damage in neural cells and Polθ's subsequent involvement in base excision repair of oxidative DNA damage, we hypothesized that Polθ contributes to CAG repeat expansion while repairing oxidative damage within HTT. Here, we performed Polθ-catalyzed in vitro DNA synthesis using various CAG•CTG repeat DNA substrates that are similar to base excision repair intermediates. We show that Polθ efficiently extends (CAG)n•(CTG)n hairpin primers, resulting in hairpin retention and repeat expansion. Polθ also triggers repeat expansions to pass the threshold for HD when the DNA template contains 35 repeats upward. Strikingly, Polθ depleted of the catalytic insertion fails to induce repeat expansions regardless of primers and templates used, indicating that the insertion sequence is responsible for Polθ's error-causing activity. In addition, the level of chromatin-bound Polθ in HD cells is significantly higher than in non-HD cells and exactly correlates with the degree of CAG repeat expansion, implying Polθ's involvement in triplet repeat instability. Therefore, we have identified Polθ as a potent factor that promotes CAG•CTG repeat expansions in HD and other neurodegenerative disorders.
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Affiliation(s)
- Kara Y Chan
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Xueying Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Janice Ortega
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Liya Gu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
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27
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Boldinova EO, Yudkina AV, Shilkin ES, Gagarinskaya DI, Baranovskiy AG, Tahirov TH, Zharkov DO, Makarova AV. Translesion activity of PrimPol on DNA with cisplatin and DNA-protein cross-links. Sci Rep 2021; 11:17588. [PMID: 34475447 PMCID: PMC8413282 DOI: 10.1038/s41598-021-96692-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/26/2021] [Indexed: 12/24/2022] Open
Abstract
Human PrimPol belongs to the archaeo-eukaryotic primase superfamily of primases and is involved in de novo DNA synthesis downstream of blocking DNA lesions and non-B DNA structures. PrimPol possesses both DNA/RNA primase and DNA polymerase activities, and also bypasses a number of DNA lesions in vitro. In this work, we have analyzed translesion synthesis activity of PrimPol in vitro on DNA with an 1,2-intrastrand cisplatin cross-link (1,2-GG CisPt CL) or a model DNA–protein cross-link (DpCL). PrimPol was capable of the 1,2-GG CisPt CL bypass in the presence of Mn2+ ions and preferentially incorporated two complementary dCMPs opposite the lesion. Nucleotide incorporation was stimulated by PolDIP2, and yeast Pol ζ efficiently extended from the nucleotides inserted opposite the 1,2-GG CisPt CL in vitro. DpCLs significantly blocked the DNA polymerase activity and strand displacement synthesis of PrimPol. However, PrimPol was able to reach the DpCL site in single strand template DNA in the presence of both Mg2+ and Mn2+ ions despite the presence of the bulky protein obstacle.
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Affiliation(s)
- Elizaveta O Boldinova
- Institute of Molecular Genetics, National Research Center «Kurchatov Institute», Kurchatov sq. 2, Moscow, Russia, 123182
| | - Anna V Yudkina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk, Russia, 630090
| | - Evgeniy S Shilkin
- Institute of Molecular Genetics, National Research Center «Kurchatov Institute», Kurchatov sq. 2, Moscow, Russia, 123182
| | - Diana I Gagarinskaya
- Institute of Molecular Genetics, National Research Center «Kurchatov Institute», Kurchatov sq. 2, Moscow, Russia, 123182
| | - Andrey G Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Tahir H Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Dmitry O Zharkov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 8 Lavrentiev Avenue, Novosibirsk, Russia, 630090.,Novosibirsk State University, 2 Pirogova St., Novosibirsk, Russia, 630090
| | - Alena V Makarova
- Institute of Molecular Genetics, National Research Center «Kurchatov Institute», Kurchatov sq. 2, Moscow, Russia, 123182.
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28
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Levanova AA, Vainio EJ, Hantula J, Poranen MM. RNA-Dependent RNA Polymerase from Heterobasidion RNA Virus 6 Is an Active Replicase In Vitro. Viruses 2021; 13:v13091738. [PMID: 34578320 PMCID: PMC8473416 DOI: 10.3390/v13091738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 11/16/2022] Open
Abstract
Heterobasidion RNA virus 6 (HetRV6) is a double-stranded (ds)RNA mycovirus and a member of the recently established genus Orthocurvulavirus within the family Orthocurvulaviridae. The purpose of the study was to determine the biochemical requirements for RNA synthesis catalyzed by HetRV6 RNA-dependent RNA polymerase (RdRp). HetRV6 RdRp was expressed in Escherichia coli and isolated to near homogeneity using liquid chromatography. The enzyme activities were studied in vitro using radiolabeled UTP. The HetRV6 RdRp was able to initiate RNA synthesis in a primer-independent manner using both virus-related and heterologous single-stranded (ss)RNA templates, with a polymerization rate of about 46 nt/min under optimal NTP concentration and temperature. NTPs with 2'-fluoro modifications were also accepted as substrates in the HetRV6 RdRp-catalyzed RNA polymerization reaction. HetRV6 RdRp transcribed viral RNA genome via semi-conservative mechanism. Furthermore, the enzyme demonstrated terminal nucleotidyl transferase (TNTase) activity. Presence of Mn2+ was required for the HetRV6 RdRp catalyzed enzymatic activities. In summary, our study shows that HetRV6 RdRp is an active replicase in vitro that can be potentially used in biotechnological applications, molecular biology, and biomedicine.
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Affiliation(s)
- Alesia A. Levanova
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00790 Helsinki, Finland
- Correspondence: (A.A.L.); (M.M.P.)
| | - Eeva J. Vainio
- Natural Resources Institute Finland, 00790 Helsinki, Finland; (E.J.V.); (J.H.)
| | - Jarkko Hantula
- Natural Resources Institute Finland, 00790 Helsinki, Finland; (E.J.V.); (J.H.)
| | - Minna M. Poranen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00790 Helsinki, Finland
- Correspondence: (A.A.L.); (M.M.P.)
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29
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In vivo evolution of an emerging zoonotic bacterial pathogen in an immunocompromised human host. Nat Commun 2021; 12:4495. [PMID: 34301946 PMCID: PMC8302680 DOI: 10.1038/s41467-021-24668-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 06/24/2021] [Indexed: 11/08/2022] Open
Abstract
Zoonotic transfer of animal pathogens to human hosts can generate novel agents, but the genetic events following such host jumps are not well studied. Here we characterize the mechanisms driving adaptive evolution of the emerging zoonotic pathogen Bordetella hinzii in a patient with interleukin-12 receptor β1 deficiency. Genomic sequencing of 24 B. hinzii isolates cultured from blood and stool over 45 months revealed a clonal lineage that had undergone extensive within-host genetic and phenotypic diversification. Twenty of 24 isolates shared an E9G substitution in the DNA polymerase III ε-subunit active site, resulting in a proofreading deficiency. Within this proofreading-deficient clade, multiple lineages with mutations in DNA repair genes and altered mutational spectra emerged and dominated clinical cultures for more than 12 months. Multiple enzymes of the tricarboxylic acid cycle and gluconeogenesis pathways were repeatedly mutated, suggesting rapid metabolic adaptation to the human environment. Furthermore, an excess of G:C > T:A transversions suggested that oxidative stress shaped genetic diversification during adaptation. We propose that inactivation of DNA proofreading activity in combination with prolonged, but sub-lethal, oxidative attack resulting from the underlying host immunodeficiency facilitated rapid genomic adaptation. These findings suggest a fundamental role for host immune phenotype in shaping pathogen evolution following zoonotic infection. Bordetella hinzii is an emerging pathogen with zoonotic risk to humans, known to be able to cause respiratory tract infection, bacteremia and endocarditis. Here, applying whole genome sequencing to bacterial isolates, the authors characterize the mechanisms driving adaptive evolution in B. hinzii in a patient with interleukin-12 receptor β1 deficiency, suggesting a role for host immune phenotype in shaping within-host pathogen evolution following zoonotic infection.
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30
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Ghosh C, Jana B. Role of Calcium in Modulating the Conformational Landscape and Peptide Binding Induced Closing of Calmodulin. J Phys Chem B 2021; 125:2317-2327. [DOI: 10.1021/acs.jpcb.1c00783] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Catherine Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Biman Jana
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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31
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Gomes-Pereira M, Monckton DG. Chronic Exposure to Cadmium and Antioxidants Does Not Affect the Dynamics of Expanded CAG•CTG Trinucleotide Repeats in a Mouse Cell Culture System of Unstable DNA. Front Cell Neurosci 2021; 14:606331. [PMID: 33603644 PMCID: PMC7884634 DOI: 10.3389/fncel.2020.606331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/29/2020] [Indexed: 12/02/2022] Open
Abstract
More than 30 human disorders are caused by the expansion of simple sequence DNA repeats, among which triplet repeats remain the most frequent. Most trinucleotide repeat expansion disorders affect primarily the nervous system, through mechanisms of neurodysfunction and/or neurodegeneration. While trinucleotide repeat tracts are short and stably transmitted in unaffected individuals, disease-associated expansions are highly dynamic in the germline and in somatic cells, with a tendency toward further expansion. Since longer repeats are associated with increasing disease severity and earlier onset of symptoms, intergenerational repeat size gains account for the phenomenon of anticipation. In turn, higher levels of age-dependent somatic expansion have been linked with increased disease severity and earlier age of onset, implicating somatic instability in the onset and progression of disease symptoms. Hence, tackling the root cause of symptoms through the control of repeat dynamics may provide therapeutic modulation of clinical manifestations. DNA repair pathways have been firmly implicated in the molecular mechanism of repeat length mutation. The demonstration that repeat expansion depends on functional DNA mismatch repair (MMR) proteins, points to MMR as a potential therapeutic target. Similarly, a role of DNA base excision repair (BER) in repeat expansion has also been suggested, particularly during the removal of oxidative lesions. Using a well-characterized mouse cell model system of an unstable CAG•CTG trinucleotide repeat, we tested if expanded repeat tracts can be stabilized by small molecules with reported roles in both pathways: cadmium (an inhibitor of MMR activity) and a variety of antioxidants (capable of neutralizing oxidative species). We found that chronic exposure to sublethal doses of cadmium and antioxidants did not result in significant reduction of the rate of trinucleotide repeat expansion. Surprisingly, manganese yielded a significant stabilization of the triplet repeat tract. We conclude that treatment with cadmium and antioxidants, at doses that do not interfere with cell survival and cell culture dynamics, is not sufficient to modify trinucleotide repeat dynamics in cell culture.
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Affiliation(s)
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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32
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Lin SN, Wuite GJ, Dame RT. Effect of Different Crowding Agents on the Architectural Properties of the Bacterial Nucleoid-Associated Protein HU. Int J Mol Sci 2020; 21:ijms21249553. [PMID: 33334011 PMCID: PMC7765392 DOI: 10.3390/ijms21249553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/31/2022] Open
Abstract
HU is a nucleoid-associated protein expressed in most eubacteria at a high amount of copies (tens of thousands). The protein is believed to bind across the genome to organize and compact the DNA. Most of the studies on HU have been carried out in a simple in vitro system, and to what extent these observations can be extrapolated to a living cell is unclear. In this study, we investigate the DNA binding properties of HU under conditions approximating physiological ones. We report that these properties are influenced by both macromolecular crowding and salt conditions. We use three different crowding agents (blotting grade blocker (BGB), bovine serum albumin (BSA), and polyethylene glycol 8000 (PEG8000)) as well as two different MgCl2 conditions to mimic the intracellular environment. Using tethered particle motion (TPM), we show that the transition between two binding regimes, compaction and extension of the HU protein, is strongly affected by crowding agents. Our observations suggest that magnesium ions enhance the compaction of HU–DNA and suppress filamentation, while BGB and BSA increase the local concentration of the HU protein by more than 4-fold. Moreover, BGB and BSA seem to suppress filament formation. On the other hand, PEG8000 is not a good crowding agent for concentrations above 9% (w/v), because it might interact with DNA, the protein, and/or surfaces. Together, these results reveal a complex interplay between the HU protein and the various crowding agents that should be taken into consideration when using crowding agents to mimic an in vivo system.
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Affiliation(s)
- Szu-Ning Lin
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands;
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Gijs J.L. Wuite
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- Correspondence: (G.J.L.W.); (R.T.D.)
| | - Remus T. Dame
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands;
- Centre for Microbial Cell Biology, Leiden University, 2333 CC Leiden, The Netherlands
- Correspondence: (G.J.L.W.); (R.T.D.)
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33
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Smethurst DGJ, Kovalev N, McKenzie ER, Pestov DG, Shcherbik N. Iron-mediated degradation of ribosomes under oxidative stress is attenuated by manganese. J Biol Chem 2020; 295:17200-17214. [PMID: 33040024 PMCID: PMC7863898 DOI: 10.1074/jbc.ra120.015025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/05/2020] [Indexed: 02/05/2023] Open
Abstract
Protein biosynthesis is fundamental to cellular life and requires the efficient functioning of the translational machinery. At the center of this machinery is the ribosome, a ribonucleoprotein complex that depends heavily on Mg2+ for structure. Recent work has indicated that other metal cations can substitute for Mg2+, raising questions about the role different metals may play in the maintenance of the ribosome under oxidative stress conditions. Here, we assess ribosomal integrity following oxidative stress both in vitro and in cells to elucidate details of the interactions between Fe2+ and the ribosome and identify Mn2+ as a factor capable of attenuating oxidant-induced Fe2+-mediated degradation of rRNA. We report that Fe2+ promotes degradation of all rRNA species of the yeast ribosome and that it is bound directly to RNA molecules. Furthermore, we demonstrate that Mn2+ competes with Fe2+ for rRNA-binding sites and that protection of ribosomes from Fe2+-mediated rRNA hydrolysis correlates with the restoration of cell viability. Our data, therefore, suggest a relationship between these two transition metals in controlling ribosome stability under oxidative stress.
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Affiliation(s)
- Daniel G J Smethurst
- Department of Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Nikolay Kovalev
- Department of Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Erica R McKenzie
- Civil and Environmental Engineering Department, Temple University, Philadelphia, Pennsylvania, USA
| | - Dimitri G Pestov
- Department of Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Natalia Shcherbik
- Department of Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, Stratford, New Jersey, USA.
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Flamme M, Röthlisberger P, Levi-Acobas F, Chawla M, Oliva R, Cavallo L, Gasser G, Marlière P, Herdewijn P, Hollenstein M. Enzymatic Formation of an Artificial Base Pair Using a Modified Purine Nucleoside Triphosphate. ACS Chem Biol 2020; 15:2872-2884. [PMID: 33090769 DOI: 10.1021/acschembio.0c00396] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The expansion of the genetic alphabet with additional, unnatural base pairs (UBPs) is an important and long-standing goal in synthetic biology. Nucleotides acting as ligands for the coordination of metal cations have advanced as promising candidates for such an expansion of the genetic alphabet. However, the inclusion of artificial metal base pairs in nucleic acids mainly relies on solid-phase synthesis approaches, and very little is known about polymerase-mediated synthesis. Herein, we report the selective and high yielding enzymatic construction of a silver-mediated base pair (dImC-AgI-dPurP) as well as a two-step protocol for the synthesis of DNA duplexes containing such an artificial metal base pair. Guided by DFT calculations, we also shed light into the mechanism of formation of this artificial base pair as well as into the structural and energetic preferences. The enzymatic synthesis of the dImC-AgI-dPurP artificial metal base pair provides valuable insights for the design of future, more potent systems aiming at expanding the genetic alphabet.
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Affiliation(s)
- Marie Flamme
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
- Université Paris Descartes, Sorbonne Paris Cité, 12 rue de l’École de Médecine, 75006 Paris, France
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, 75005 Paris, France
| | - Pascal Röthlisberger
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Fabienne Levi-Acobas
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Mohit Chawla
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal, 23955-6900 Saudi Arabia
| | - Romina Oliva
- Department of Sciences and Technologies, University Parthenope of Naples, Centro Direzionale Isola C4, 80143, Naples, Italy
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal, 23955-6900 Saudi Arabia
| | - Gilles Gasser
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, 75005 Paris, France
| | - Philippe Marlière
- University of Paris Saclay, CNRS, iSSB, UEVE, Genopole, 5 Rue Henri Desbrueres, 91030 Evry, France
| | - Piet Herdewijn
- KU Leuven, Rega Institute for Medical Research, Medicinal Chemistry, Herestraat, 3000 Leuven, Belgium
| | - Marcel Hollenstein
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
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Garafutdinov RR, Kupova OY, Gilvanov AR, Sakhabutdinova AR. Data on molecular docking simulations of quaternary complexes 'Bst exo- polymerase-DNA-dCTP-metal cations'. Data Brief 2020; 33:106549. [PMID: 33299910 PMCID: PMC7704292 DOI: 10.1016/j.dib.2020.106549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 11/30/2022] Open
Abstract
This article reports data related to the research article entitled “Effect of metal ions on isothermal amplification with Bst exo- DNA polymerase” (R.R. Garafutdinov, A.R. Gilvanov, O.Y. Kupova, A.R. Sakhabutdinova, 2020) [1]. Here, the results of molecular simulations of the complexes of Bst exo- DNA polymerase with dCTP triphosphate, double-stranded DNA and divalent metal cations are presented. Energetic parameters, number and type of chemical bonds formed by dCTP with the environment are given.
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Affiliation(s)
- Ravil R Garafutdinov
- Institute of Biochemistry and Genetics, Ufa Federal Research Center of the Russian Academy of Sciences, Ufa, Russia
| | - Olga Yu Kupova
- Institute of Biochemistry and Genetics, Ufa Federal Research Center of the Russian Academy of Sciences, Ufa, Russia.,Ufa State Petroleum Technological University, Ufa, Russia
| | - Aidar R Gilvanov
- Institute of Biochemistry and Genetics, Ufa Federal Research Center of the Russian Academy of Sciences, Ufa, Russia
| | - Assol R Sakhabutdinova
- Institute of Biochemistry and Genetics, Ufa Federal Research Center of the Russian Academy of Sciences, Ufa, Russia
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Chen Z, Tang Y, Hua Y, Zhao Y. Structural features and functional implications of proteins enabling the robustness of Deinococcus radiodurans. Comput Struct Biotechnol J 2020; 18:2810-2817. [PMID: 33133422 PMCID: PMC7575645 DOI: 10.1016/j.csbj.2020.09.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 12/21/2022] Open
Abstract
Deinococcus radiodurans can survive under extreme conditions, including high doses of DNA damaging agents and ionizing radiation, desiccation, and oxidative stress. Both the efficient cellular DNA repair machinery and antioxidation systems contribute to the extreme resistance of this bacterium, making it an ideal organism for studying the cellular mechanisms of environmental adaptation. The number of stress-related proteins identified in this bacterium has mushroomed in the past two decades. The newly identified proteins reveal both commonalities and diversity of structure, mechanism, and function, which impact a wide range of cellular functions. Here, we review the unique and general structural features of these proteins and discuss how these studies improve our understanding of the environmental stress adaptation mechanisms of D. radiodurans.
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Affiliation(s)
- Zijing Chen
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.,MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yuyue Tang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.,MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yuejin Hua
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.,MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ye Zhao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.,MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang University, Hangzhou, Zhejiang, China
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Garafutdinov RR, Gilvanov AR, Kupova OY, Sakhabutdinova AR. Effect of metal ions on isothermal amplification with Bst exo- DNA polymerase. Int J Biol Macromol 2020; 161:1447-1455. [DOI: 10.1016/j.ijbiomac.2020.08.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/02/2020] [Accepted: 08/04/2020] [Indexed: 01/28/2023]
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Chatterjee S, Kumari S, Rath S, Priyadarshanee M, Das S. Diversity, structure and regulation of microbial metallothionein: metal resistance and possible applications in sequestration of toxic metals. Metallomics 2020; 12:1637-1655. [PMID: 32996528 DOI: 10.1039/d0mt00140f] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metallothioneins (MTs) are a group of cysteine-rich, universal, low molecular weight proteins distributed widely in almost all major taxonomic groups ranging from tiny microbes to highly organized vertebrates. The primary function of this protein is storage, transportation and binding of metals, which enable microorganisms to detoxify heavy metals. In the microbial world, these peptides were first identified in a cyanobacterium Synechococcus as the SmtA protein which exhibits high affinity towards rising level of zinc and cadmium to preserve metal homeostasis in a cell. In yeast, MTs aid in reserving copper and confer protection against copper toxicity by chelating excess copper ions in a cell. Two MTs, CUP1 and Crs5, originating from Saccharomyces cerevisiae predominantly bind to copper though are capable of binding with zinc and cadmium ions. MT superfamily 7 is found in ciliated protozoa which show high affinity towards copper and cadmium. Several tools and techniques, such as western blot, capillary electrophoresis, inductively coupled plasma, atomic emission spectroscopy and high performance liquid chromatography, have been extensively utilized for the detection and quantification of microbial MTs which are utilized for the efficient remediation and sequestration of heavy metals from a contaminated environment.
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Affiliation(s)
- Shreosi Chatterjee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769 008, Odisha, India.
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Engineered viral DNA polymerase with enhanced DNA amplification capacity: a proof-of-concept of isothermal amplification of damaged DNA. Sci Rep 2020; 10:15046. [PMID: 32929102 PMCID: PMC7490695 DOI: 10.1038/s41598-020-71773-6] [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: 01/29/2020] [Accepted: 08/20/2020] [Indexed: 11/24/2022] Open
Abstract
The development of whole genome amplification (WGA) and related methods, coupled with the dramatic growth of sequencing capacities, has changed the paradigm of genomic and genetic analyses. This has led to a continual requirement of improved DNA amplification protocols and the elaboration of new tailored methods. As key elements in WGA, identification and engineering of novel, faithful and processive DNA polymerases is a driving force in the field. We have engineered the B-family DNA polymerase of virus Bam35 with a C-terminal fusion of DNA-binding motifs. The new protein, named B35-HhH, shows faithful DNA replication in the presence of magnesium or an optimised combination of magnesium and manganese divalent cofactors, which enhances the replication of damaged DNA substrates. Overall, the newly generated variant displays improved amplification performance, sensitivity, translesion synthesis and resistance to salt, which are of great interest for several applications of isothermal DNA amplification. Further, rolling-circle amplification of abasic site-containing minicircles provides a proof-of-concept for using B35-HhH for processive amplification of damaged DNA samples.
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The (p)ppGpp Synthetase RSH Mediates Stationary-Phase Onset and Antibiotic Stress Survival in Clostridioides difficile. J Bacteriol 2020; 202:JB.00377-20. [PMID: 32661079 DOI: 10.1128/jb.00377-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 12/31/2022] Open
Abstract
The human pathogen Clostridioides difficile is increasingly tolerant of multiple antibiotics and causes infections with a high rate of recurrence, creating an urgent need for new preventative and therapeutic strategies. The stringent response, a universal bacterial response to extracellular stress, governs antibiotic survival and pathogenesis in diverse organisms but has not previously been characterized in C. difficile Here, we report that the C. difficile (p)ppGpp synthetase RSH is incapable of utilizing GTP or GMP as a substrate but readily synthesizes ppGpp from GDP. The enzyme also utilizes many structurally diverse metal cofactors for reaction catalysis and remains functionally stable at a wide range of environmental pHs. Transcription of rsh is stimulated by stationary-phase onset and by exposure to the antibiotics clindamycin and metronidazole. Chemical inhibition of RSH by the ppGpp analog relacin increases antibiotic susceptibility in epidemic C. difficile R20291, indicating that RSH inhibitors may be a viable strategy for drug development against C. difficile infection. Finally, transcriptional suppression of rsh also increases bacterial antibiotic susceptibility, suggesting that RSH contributes to C. difficile antibiotic tolerance and survival.IMPORTANCE Clostridioides difficile infection (CDI) is an urgent public health threat with a high recurrence rate, in part because the causative bacterium has a high rate of antibiotic survival. The (p)ppGpp-mediated bacterial stringent response plays a role in antibiotic tolerance in diverse pathogens and is a potential target for development of new antimicrobials because the enzymes that metabolize (p)ppGpp have no mammalian homologs. We report that stationary-phase onset and antibiotics induce expression of the clostridial ppGpp synthetase RSH and that both chemical inhibition and translational suppression of RSH increase C. difficile antibiotic susceptibility. This demonstrates that development of RSH inhibitors to serve as adjuvants to antibiotic therapy is a potential approach for the development of new strategies to combat CDI.
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López-Laguna H, Sánchez J, Unzueta U, Mangues R, Vázquez E, Villaverde A. Divalent Cations: A Molecular Glue for Protein Materials. Trends Biochem Sci 2020; 45:992-1003. [PMID: 32891514 DOI: 10.1016/j.tibs.2020.08.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/30/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023]
Abstract
Among inorganic materials, divalent cations modulate thousands of physiological processes that support life. Their roles in protein assembly and aggregation are less known, although they are progressively being brought to light. We review the structural roles of divalent cations here, as well as the novel protein materials that are under development, in which they are used as glue-like agents. More specifically, we discuss how mechanically stable nanoparticles, fibers, matrices, and hydrogels are generated through their coordination with histidine-rich proteins. We also describe how the rational use of divalent cations combined with simple protein engineering offers unexpected and very simple biochemical approaches to biomaterial design that might address unmet clinical needs in precision medicine.
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Affiliation(s)
- Hèctor López-Laguna
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain
| | - Julieta Sánchez
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT) (CONICET-Universidad Nacional de Córdoba), ICTA & Cátedra de Química Biológica, Departamento de Química, FCEFyN, X 5016GCA, Córdoba, Argentina
| | - Ugutz Unzueta
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain; Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, 08041 Barcelona, Spain; Josep Carreras Research Institute, 08041 Barcelona, Spain.
| | - Ramón Mangues
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain; Biomedical Research Institute Sant Pau (IIB-Sant Pau), Hospital de la Santa Creu i Sant Pau, 08041 Barcelona, Spain; Josep Carreras Research Institute, 08041 Barcelona, Spain
| | - Esther Vázquez
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain
| | - Antonio Villaverde
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain.
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Flamme M, Levi-Acobas F, Hensel S, Naskar S, Röthlisberger P, Sarac I, Gasser G, Müller J, Hollenstein M. Enzymatic Construction of Artificial Base Pairs: The Effect of Metal Shielding. Chembiochem 2020; 21:3398-3409. [PMID: 32673442 DOI: 10.1002/cbic.202000402] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/16/2020] [Indexed: 12/12/2022]
Abstract
Th formation of metal base pairs is a versatile method for the introduction of metal cations into nucleic acids that has been used in numerous applications including the construction of metal nanowires, development of energy, charge-transfer devices and expansion of the genetic alphabet. As an alternative, enzymatic construction of metal base pairs is an alluring strategy that grants access to longer sequences and offers the possibility of using such unnatural base pairs (UBPs) in SELEX experiments for the identification of functional nucleic acids. This method remains rather underexplored, and a better understanding of the key parameters in the design of efficient nucleotides is required. We have investigated the effect of methylation of the imidazole nucleoside (dImnMe TP) on the efficiency of the enzymatic construction of metal base pairs. The presence of methyl substituents on dImTP facilitates the polymerase-driven formation of dIm4Me -AgI -dIm and dIm2Me TP-CrIII -dIm base pairs. Steric factors rather than the basicity of the imidazole nucleobase appear to govern the enzymatic formation of such metal base pairs. We also demonstrate the compatibility of other metal cations rarely considered in the construction of artificial metal bases by enzymatic DNA synthesis under both primer extension reaction and PCR conditions. These findings open up new directions for the design of nucleotide analogues for the development of metal base pairs.
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Affiliation(s)
- Marie Flamme
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724, Paris Cedex 15, France.,Université Paris Descartes, Sorbonne Paris Cité, 12 rue de l'École de Médecine, 75006, Paris, France.,Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, 11, rue Pierre et Marie Curie, 75005, Paris, France
| | - Fabienne Levi-Acobas
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Susanne Hensel
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, Corrensstrasse 30, 48149, Münster, Germany
| | - Shuvankar Naskar
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, Corrensstrasse 30, 48149, Münster, Germany
| | - Pascal Röthlisberger
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Ivo Sarac
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Gilles Gasser
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, 11, rue Pierre et Marie Curie, 75005, Paris, France
| | - Jens Müller
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, Corrensstrasse 30, 48149, Münster, Germany
| | - Marcel Hollenstein
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724, Paris Cedex 15, France
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Liu X, Zhang Q, Knoll W, Liedberg B, Wang Y. Rational Design of Functional Peptide-Gold Hybrid Nanomaterials for Molecular Interactions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000866. [PMID: 32743897 DOI: 10.1002/adma.202000866] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/21/2020] [Indexed: 05/12/2023]
Abstract
Gold nanoparticles (AuNPs) have been extensively used for decades in biosensing-related development due to outstanding optical properties. Peptides, as newly realized functional biomolecules, are promising candidates of replacing antibodies, receptors, and substrates for specific molecular interactions. Both peptides and AuNPs are robust and easily synthesized at relatively low cost. Hence, peptide-AuNP-based bio-nano-technological approaches have drawn increasing interest, especially in the field of molecular targeting, cell imaging, drug delivery, and therapy. Many excellent works in these areas have been reported: demonstrating novel ideas, exploring new targets, and facilitating advanced diagnostic and therapeutic technologies. Importantly, some of them also have been employed to address real practical problems, especially in remote and less privileged areas. This contribution focuses on the application of peptide-gold hybrid nanomaterials for various molecular interactions, especially in biosensing/diagnostics and cell targeting/imaging, as well as for the development of highly active antimicrobial/antifouling coating strategies. Rationally designed peptide-gold nanomaterials with functional properties are discussed along with future challenges and opportunities.
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Affiliation(s)
- Xiaohu Liu
- School of Biomedical Engineering, School of Ophthalmology & Optometry, Wenzhou Medical University, Xueyuan Road 270, Wenzhou, 325027, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Xinsan Road 16, Wenzhou, 325001, China
| | - Qingwen Zhang
- School of Biomedical Engineering, School of Ophthalmology & Optometry, Wenzhou Medical University, Xueyuan Road 270, Wenzhou, 325027, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Xinsan Road 16, Wenzhou, 325001, China
| | - Wolfgang Knoll
- Austrian Institute of Technology, Giefinggasse 4, Vienna, 1210, Austria
| | - Bo Liedberg
- Centre for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Yi Wang
- School of Biomedical Engineering, School of Ophthalmology & Optometry, Wenzhou Medical University, Xueyuan Road 270, Wenzhou, 325027, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Xinsan Road 16, Wenzhou, 325001, China
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Li P, Rangadurai A, Al-Hashimi HM, Hammes-Schiffer S. Environmental Effects on Guanine-Thymine Mispair Tautomerization Explored with Quantum Mechanical/Molecular Mechanical Free Energy Simulations. J Am Chem Soc 2020; 142:11183-11191. [PMID: 32459476 DOI: 10.1021/jacs.0c03774] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
DNA bases can adopt energetically unfavorable tautomeric forms that enable the formation of Watson-Crick-like (WC-like) mispairs, which have been proposed to give rise to spontaneous mutations in DNA and misincorporation errors in DNA replication and translation. Previous NMR and computational studies have indicated that the population of WC-like guanine-thymine (G-T) mispairs depends on the environment, such as the local nucleic acid sequence and solvation. To investigate these environmental effects, herein G-T mispair tautomerization processes are studied computationally in aqueous solution, in A-form and B-form DNA duplexes, and within the active site of a DNA polymerase λ variant. The wobble G-T (wG-T), WC-like G-T*, and WC-like G*-T forms are considered, where * indicates the enol tautomer of the base. The minimum free energy paths for the tautomerization from the wG-T to the WC-like G-T* and from the WC-like G-T* to the WC-like G*-T are computed with mixed quantum mechanical/molecular mechanical (QM/MM) free energy simulations. The reaction free energies and free energy barriers are found to be significantly influenced by the environment. The wG-T→G-T* tautomerization is predicted to be endoergic in aqueous solution and the DNA duplexes but slightly exoergic in the polymerase, with Arg517 and Asn513 providing electrostatic stabilization of G-T*. The G-T*→G*-T tautomerization is also predicted to be slightly more thermodynamically favorable in the polymerase relative to these DNA duplexes. These simulations are consistent with an experimentally driven kinetic misincorporation model suggesting that G-T mispair tautomerization occurs in the ajar polymerase conformation or concertedly with the transition from the ajar to the closed polymerase conformation. Furthermore, the order of the associated two proton transfer reactions is predicted to be different in the polymerase than in aqueous solution and the DNA duplexes. These studies highlight the impact of the environment on the thermodynamics, kinetics, and fundamental mechanisms of G-T mispair tautomerization, which plays a role in a wide range of biochemically important processes.
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Affiliation(s)
- Pengfei Li
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Atul Rangadurai
- Department of Biochemistry, Duke University, Durham, North Carolina 27710, United States
| | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University, Durham, North Carolina 27710, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
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Hooy RM, Massaccesi G, Rousseau KE, Chattergoon MA, Sohn J. Allosteric coupling between Mn2+ and dsDNA controls the catalytic efficiency and fidelity of cGAS. Nucleic Acids Res 2020; 48:4435-4447. [PMID: 32170294 PMCID: PMC7192592 DOI: 10.1093/nar/gkaa084] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/24/2020] [Accepted: 03/11/2020] [Indexed: 12/21/2022] Open
Abstract
Cyclic-G/AMP (cGAMP) synthase (cGAS) triggers host innate immune responses against cytosolic double-stranded (ds)DNA arising from genotoxic stress and pathogen invasion. The canonical activation mechanism of cGAS entails dsDNA-binding and dimerization. Here, we report an unexpected activation mechanism of cGAS in which Mn2+ activates monomeric cGAS without dsDNA. Importantly, the Mn2+-mediated activation positively couples with dsDNA-dependent activation in a concerted manner. Moreover, the positive coupling between Mn2+ and dsDNA length-dependent activation requires the cognate ATP/GTP substrate pair, while negative-cooperativity suppresses Mn2+ utilization by either ATP or GTP alone. Additionally, while Mn2+ accelerates the overall catalytic activity, dsDNA length-dependent dimerization specifically accelerates the cyclization of cGAMP. Together, we demonstrate how the intrinsic allostery of cGAS efficiently yet precisely tunes its activity.
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Affiliation(s)
- Richard M Hooy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guido Massaccesi
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kimberly E Rousseau
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael A Chattergoon
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Gottesman ME, Chudaev M, Mustaev A. Key features of magnesium that underpin its role as the major ion for electrophilic biocatalysis. FEBS J 2020; 287:5439-5463. [DOI: 10.1111/febs.15318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 02/06/2020] [Accepted: 03/30/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Max E. Gottesman
- Department of Microbiology & Immunology Columbia University Medical Center New York NY USA
| | - Maxim Chudaev
- Public Health Research Institute & Department of Microbiology and Molecular Genetics New Jersey Medical School Rutgers Biomedical and Health Sciences Newark NJ USA
| | - Arkady Mustaev
- Public Health Research Institute & Department of Microbiology and Molecular Genetics New Jersey Medical School Rutgers Biomedical and Health Sciences Newark NJ USA
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47
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Wang Y, Liu T, Yu T, Tan ZJ, Zhang W. Salt effect on thermodynamics and kinetics of a single RNA base pair. RNA (NEW YORK, N.Y.) 2020; 26:470-480. [PMID: 31988191 PMCID: PMC7075264 DOI: 10.1261/rna.073882.119] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/11/2020] [Indexed: 05/09/2023]
Abstract
Due to the polyanionic nature of RNAs, the structural folding of RNAs are sensitive to solution salt conditions, while there is still lack of a deep understanding of the salt effect on the thermodynamics and kinetics of RNAs at a single base-pair level. In this work, the thermodynamic and the kinetic parameters for the base-pair AU closing/opening at different salt concentrations were calculated by 3-µsec all-atom molecular dynamics (MD) simulations at different temperatures. It was found that for the base-pair formation, the enthalpy change [Formula: see text] is nearly independent of salt concentration, while the entropy change [Formula: see text] exhibits a linear dependence on the logarithm of salt concentration, verifying the empirical assumption based on thermodynamic experiments. Our analyses revealed that such salt concentration dependence of the entropy change mainly results from the dependence of ion translational entropy change for the base pair closing/opening on salt concentration. Furthermore, the closing rate increases with the increasing of salt concentration, while the opening rate is nearly independent of salt concentration. Additionally, our analyses revealed that the free energy surface for describing the base-pair opening and closing dynamics becomes more rugged with the decrease of salt concentration.
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Affiliation(s)
- Yujie Wang
- Department of Physics and Key Laboratory of Artificial Micro and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei, 430072, P.R. China
- Department of Physics and Telecommunication Engineering, Zhoukou Normal University, Zhoukou, Henan, 466001, P.R. China
| | - Taigang Liu
- Department of Physics and Key Laboratory of Artificial Micro and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei, 430072, P.R. China
- School of Medical Engineering, Xinxiang Medical University, Xinxiang, Henan, 453003, P.R. China
| | - Ting Yu
- Department of Physics and Key Laboratory of Artificial Micro and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei, 430072, P.R. China
| | - Zhi-Jie Tan
- Department of Physics and Key Laboratory of Artificial Micro and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei, 430072, P.R. China
| | - Wenbing Zhang
- Department of Physics and Key Laboratory of Artificial Micro and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei, 430072, P.R. China
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48
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Nasef M, Muffly MC, Beckman AB, Rowe SJ, Walker FC, Hatoum-Aslan A, Dunkle JA. Regulation of cyclic oligoadenylate synthesis by the Staphylococcus epidermidis Cas10-Csm complex. RNA (NEW YORK, N.Y.) 2019; 25:948-962. [PMID: 31076459 PMCID: PMC6633199 DOI: 10.1261/rna.070417.119] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
CRISPR-Cas systems are a class of adaptive immune systems in prokaryotes that use small CRISPR RNAs (crRNAs) in conjunction with CRISPR-associated (Cas) nucleases to recognize and degrade foreign nucleic acids. Recent studies have revealed that Type III CRISPR-Cas systems synthesize second messenger molecules previously unknown to exist in prokaryotes, cyclic oligoadenylates (cOA). These molecules activate the Csm6 nuclease to promote RNA degradation and may also coordinate additional cellular responses to foreign nucleic acids. Although cOA production has been reconstituted and characterized for a few bacterial and archaeal Type III systems, cOA generation and its regulation have not been explored for the Staphylococcus epidermidis Type III-A CRISPR-Cas system, a longstanding model for CRISPR-Cas function. Here, we demonstrate that this system performs Mg2+-dependent synthesis of 3-6 nt cOA. We show that activation of cOA synthesis is perturbed by single nucleotide mismatches between the crRNA and target RNA at discrete positions, and that synthesis is antagonized by Csm3-mediated target RNA cleavage. Altogether, our results establish the requirements for cOA production in a model Type III CRISPR-Cas system and suggest a natural mechanism to dampen immunity once the foreign RNA is destroyed.
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Affiliation(s)
- Mohamed Nasef
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Mary C Muffly
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Andrew B Beckman
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Sebastian J Rowe
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Forrest C Walker
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Asma Hatoum-Aslan
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Jack A Dunkle
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
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49
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Baker YR, Chen J, Brown J, El-Sagheer AH, Wiseman P, Johnson E, Goddard P, Brown T. Preparation and characterization of manganese, cobalt and zinc DNA nanoflowers with tuneable morphology, DNA content and size. Nucleic Acids Res 2019; 46:7495-7505. [PMID: 30010979 PMCID: PMC6125639 DOI: 10.1093/nar/gky630] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 06/29/2018] [Indexed: 12/11/2022] Open
Abstract
Recently reported DNA nanoflowers are an interesting class of organic-inorganic hybrid materials which are prepared using DNA polymerases. DNA nanoflowers combine the high surface area and scaffolding of inorganic Mg2P2O7 nanocrystals with the targeting properties of DNA, whilst adding enzymatic stability and enhanced cellular uptake. We have investigated conditions for chemically modifying the inorganic core of these nanoflowers through substitution of Mg2+ with Mn2+, Co2+ or Zn2+ and have characterized the resulting particles. These have a range of novel nanoarchitectures, retain the enzymatic stability of their magnesium counterparts and the Co2+ and Mn2+ DNA nanoflowers have added magnetic properties. We investigate conditions to control different morphologies, DNA content, hybridization properties, and size. Additionally, we show that DNA nanoflower production is not limited to Ф29 DNA polymerase and that the choice of polymerase can influence the DNA length within the constructs. We anticipate that the added control of structure, size and chemistry will enhance future applications.
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Affiliation(s)
- Ysobel R Baker
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire OX1 3TA, UK
| | - Jinfeng Chen
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire OX1 3TA, UK
| | - Jason Brown
- Department of Physics, University of Oxford, Oxford, Oxfordshire OX1 3PU, UK
| | - Afaf H El-Sagheer
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire OX1 3TA, UK.,Chemistry Branch, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43721, Egypt
| | - Philip Wiseman
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire OX1 3TA, UK
| | - Errin Johnson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Paul Goddard
- Department of Physics, University of Warwick, Coventry, Warwickshire CV4 7AL, UK
| | - Tom Brown
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire OX1 3TA, UK
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50
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Chang YK, Huang YP, Liu XX, Ko TP, Bessho Y, Kawano Y, Maestre-Reyna M, Wu WJ, Tsai MD. Human DNA Polymerase μ Can Use a Noncanonical Mechanism for Multiple Mn 2+-Mediated Functions. J Am Chem Soc 2019; 141:8489-8502. [PMID: 31067051 DOI: 10.1021/jacs.9b01741] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Recent research on the structure and mechanism of DNA polymerases has continued to generate fundamentally important features, including a noncanonical pathway involving "prebinding" of metal-bound dNTP (MdNTP) in the absence of DNA. While this noncanonical mechanism was shown to be a possible subset for African swine fever DNA polymerase X (Pol X) and human Pol λ, it remains unknown whether it could be the primary pathway for a DNA polymerase. Pol μ is a unique member of the X-family with multiple functions and with unusual Mn2+ preference. Here we report that Pol μ not only prebinds MdNTP in a catalytically active conformation but also exerts a Mn2+ over Mg2+ preference at this early stage of catalysis, for various functions: incorporation of dNTP into a single nucleotide gapped DNA, incorporation of rNTP in the nonhomologous end joining (NHEJ) repair, incorporation of dNTP to an ssDNA, and incorporation of an 8-oxo-dGTP opposite template dA (mismatched) or dC (matched). The structural basis of this noncanonical mechanism and Mn2+ over Mg2+ preference in these functions was analyzed by solving 19 structures of prebinding binary complexes, precatalytic ternary complexes, and product complexes. The results suggest that the noncanonical pathway is functionally relevant for the multiple functions of Pol μ. Overall, this work provides the structural and mechanistic basis for the long-standing puzzle in the Mn2+ preference of Pol μ and expands the landscape of the possible mechanisms of DNA polymerases to include both mechanistic pathways.
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Affiliation(s)
- Yao-Kai Chang
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan.,Institute of Biochemical Sciences , National Taiwan University , Taipei 106 , Taiwan
| | - Ya-Ping Huang
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan
| | - Xiao-Xia Liu
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan
| | - Yoshitaka Bessho
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan.,RIKEN SPring-8 Center , 1-1-1 Kouto , Sayo , Hyogo 679-5148 , Japan
| | - Yoshiaki Kawano
- RIKEN SPring-8 Center , 1-1-1 Kouto , Sayo , Hyogo 679-5148 , Japan
| | - Manuel Maestre-Reyna
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan
| | - Wen-Jin Wu
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan
| | - Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica , 128 Academia Road Sec. 2 , Nankang, Taipei 115 , Taiwan.,Institute of Biochemical Sciences , National Taiwan University , Taipei 106 , Taiwan
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