1
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Guo Z, Wang S, Wang Y, Wang Z, Ou G. A machine learning enhanced EMS mutagenesis probability map for efficient identification of causal mutations in Caenorhabditis elegans. PLoS Genet 2024; 20:e1011377. [PMID: 39186782 PMCID: PMC11379379 DOI: 10.1371/journal.pgen.1011377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 09/06/2024] [Accepted: 07/27/2024] [Indexed: 08/28/2024] Open
Abstract
Chemical mutagenesis-driven forward genetic screens are pivotal in unveiling gene functions, yet identifying causal mutations behind phenotypes remains laborious, hindering their high-throughput application. Here, we reveal a non-uniform mutation rate caused by Ethyl Methane Sulfonate (EMS) mutagenesis in the C. elegans genome, indicating that mutation frequency is influenced by proximate sequence context and chromatin status. Leveraging these factors, we developed a machine learning enhanced pipeline to create a comprehensive EMS mutagenesis probability map for the C. elegans genome. This map operates on the principle that causative mutations are enriched in genetic screens targeting specific phenotypes among random mutations. Applying this map to Whole Genome Sequencing (WGS) data of genetic suppressors that rescue a C. elegans ciliary kinesin mutant, we successfully pinpointed causal mutations without generating recombinant inbred lines. This method can be adapted in other species, offering a scalable approach for identifying causal genes and revitalizing the effectiveness of forward genetic screens.
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Affiliation(s)
- Zhengyang Guo
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Shimin Wang
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Yang Wang
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Zi Wang
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing, China
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2
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Anderson RF, Shinde SS, Andrau L, Leung B, Skene C, White JM, Lobachevsky PN, Martin RF. Chemical Repair of Radical Damage to the GC Base Pair by DNA-Bound Bisbenzimidazoles. J Phys Chem B 2024. [PMID: 38686959 DOI: 10.1021/acs.jpcb.4c01069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The migration of an electron-loss center (hole) in calf thymus DNA to bisbenzimidazole ligands bound in the minor groove is followed by pulse radiolysis combined with time-resolved spectrophotometry. The initially observed absorption spectrum upon oxidation of DNA by the selenite radical is consistent with spin on cytosine (C), as the GC• pair neutral radical, followed by the spectra of oxidized ligands. The rate of oxidation of bound ligands increased with an increase in the ratio (r) ligands per base pair from 0.005 to 0.04. Both the rate of ligand oxidation and the estimated range of hole transfer (up to 30 DNA base pairs) decrease with the decrease in one-electron reduction potential between the GC• pair neutral radical of ca. 1.54 V and that of the ligand radicals (E0', 0.90-0.99 V). Linear plots of log of the rate of hole transfer versus r give a common intercept at r = 0 and a free energy change of 12.2 ± 0.3 kcal mol-1, ascribed to the GC• pair neutral radical undergoing a structural change, which is in competition to the observed hole transfer along DNA. The rate of hole transfer to the ligands at distance, R, from the GC• pair radical, k2, is described by the relationship k2 = k0 exp(constant/R), where k0 includes the rate constant for surmounting a small barrier.
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Affiliation(s)
- Robert F Anderson
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand
- Auckland Cancer Society Research Centre, University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand
| | - Sujata S Shinde
- Auckland Cancer Society Research Centre, University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand
| | - Laura Andrau
- School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
| | - Brenda Leung
- School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
| | - Colin Skene
- School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
| | - Jonathan M White
- School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
| | - Pavel N Lobachevsky
- Molecular Radiation Biology, Peter MacCallum Cancer Centre, Melbourne 3052, Australia
| | - Roger F Martin
- School of Chemistry and Bio-21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
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3
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Kim JM. Molecular Link between DNA Damage Response and Microtubule Dynamics. Int J Mol Sci 2022; 23:ijms23136986. [PMID: 35805981 PMCID: PMC9266319 DOI: 10.3390/ijms23136986] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 11/16/2022] Open
Abstract
Microtubules are major components of the cytoskeleton that play important roles in cellular processes such as intracellular transport and cell division. In recent years, it has become evident that microtubule networks play a role in genome maintenance during interphase. In this review, we highlight recent advances in understanding the role of microtubule dynamics in DNA damage response and repair. We first describe how DNA damage checkpoints regulate microtubule organization and stability. We then highlight how microtubule networks are involved in the nuclear remodeling following DNA damage, which leads to changes in chromosome organization. Lastly, we discuss how microtubule dynamics participate in the mobility of damaged DNA and promote consequent DNA repair. Together, the literature indicates the importance of microtubule dynamics in genome organization and stability during interphase.
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Affiliation(s)
- Jung Min Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 58128, Korea
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4
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5
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Alternative σ Factors Regulate Overlapping as Well as Distinct Stress Response and Metabolic Functions in Listeria monocytogenes under Stationary Phase Stress Condition. Pathogens 2021; 10:pathogens10040411. [PMID: 33915780 PMCID: PMC8066629 DOI: 10.3390/pathogens10040411] [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: 02/22/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022] Open
Abstract
Listeria monocytogenes can regulate and fine-tune gene expression, to adapt to diverse stress conditions encountered during foodborne transmission. To further understand the contributions of alternative sigma (σ) factors to the regulation of L. monocytogenes gene expression, RNA-Seq was performed on L. monocytogenes strain 10403S and five isogenic mutants (four strains bearing in-frame null mutations in three out of four alternative σ factor genes, ΔCHL, ΔBHL, ΔBCL, and ΔBCH, and one strain bearing null mutations in all four genes, ΔBCHL), grown to stationary phase. Our data showed that 184, 35, 34, and 20 genes were positively regulated by σB, σL, σH, and σC (posterior probability > 0.9 and Fold Change (FC) > 5.0), respectively. Moreover, σB-dependent genes showed the highest FC (based on comparisons between the ΔCHL and the ΔBCHL strain), with 44 genes showing an FC > 100; only four σL-dependent, and no σH- or σC-dependent genes showed FC >100. While σB-regulated genes identified in this study are involved in stress-associated functions and metabolic pathways, σL appears to largely regulate genes involved in a few specific metabolic pathways, including positive regulation of operons encoding phosphoenolpyruvate (PEP)-dependent phosphotransferase systems (PTSs). Overall, our data show that (i) σB and σL directly and indirectly regulate genes involved in several energy metabolism-related functions; (ii) alternative σ factors are involved in complex regulatory networks and appear to have epistatic effects in stationary phase cells; and (iii) σB regulates multiple stress response pathways, while σL and σH positively regulate a smaller number of specific pathways.
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6
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Williams SM, Chatterji D. An Overview of Dps: Dual Acting Nanovehicles in Prokaryotes with DNA Binding and Ferroxidation Properties. Subcell Biochem 2021; 96:177-216. [PMID: 33252729 DOI: 10.1007/978-3-030-58971-4_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
DNA binding proteins under starvation (Dps) are proteins belonging to the ferritin family with the capacity for DNA binding, in addition to iron storage and ferroxidation. Present only in the prokaryotes, these multifaceted proteins have been assigned with a number of roles, from pathogenesis to nucleoid condensation and protection. They have a significant role in protecting the cells from free radical assaults, indirectly by sequestration of iron and by directly binding to the DNA. Due to their symmetry, stability and biomineralization capacity, these proteins have ever increasing potential applications in biotechnology and drug delivery. This chapter tries to bring together all these aspects of Dps in the view of current understanding and older perspectives by studies of our group as well as other experts in the field.
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Affiliation(s)
- Sunanda Margrett Williams
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, WC1E 7HX, United Kingdom.
| | - Dipankar Chatterji
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
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7
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Biochemistry of Copper Site Assembly in Heme-Copper Oxidases: A Theme with Variations. Int J Mol Sci 2019; 20:ijms20153830. [PMID: 31387303 PMCID: PMC6696091 DOI: 10.3390/ijms20153830] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/18/2023] Open
Abstract
Copper is an essential cofactor for aerobic respiration, since it is required as a redox cofactor in Cytochrome c Oxidase (COX). This ancient and highly conserved enzymatic complex from the family of heme-copper oxidase possesses two copper sites: CuA and CuB. Biosynthesis of the oxidase is a complex, stepwise process that requires a high number of assembly factors. In this review, we summarize the state-of-the-art in the assembly of COX, with special emphasis in the assembly of copper sites. Assembly of the CuA site is better understood, being at the same time highly variable among organisms. We also discuss the current challenges that prevent the full comprehension of the mechanisms of assembly and the pending issues in the field.
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8
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Gottschlich L, Geiser P, Bortfeld-Miller M, Field CM, Vorholt JA. Complex general stress response regulation in Sphingomonas melonis Fr1 revealed by transcriptional analyses. Sci Rep 2019; 9:9404. [PMID: 31253827 PMCID: PMC6599016 DOI: 10.1038/s41598-019-45788-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/12/2019] [Indexed: 01/31/2023] Open
Abstract
The general stress response (GSR) represents an important trait to survive in the environment by leading to multiple stress resistance. In alphaproteobacteria, the GSR is under the transcriptional control of the alternative sigma factor EcfG. Here we performed transcriptome analyses to investigate the genes controlled by EcfG of Sphingomonas melonis Fr1 and the plasticity of this regulation under stress conditions. We found that EcfG regulates genes for proteins that are typically associated with stress responses. Moreover, EcfG controls regulatory proteins, which likely fine-tune the GSR. Among these, we identified a novel negative GSR feedback regulator, termed NepR2, on the basis of gene reporter assays, phenotypic analyses, and biochemical assays. Transcriptional profiling of signaling components upstream of EcfG under complex stress conditions showed an overall congruence with EcfG-regulated genes. Interestingly however, we found that the GSR is transcriptionally linked to the regulation of motility and biofilm formation via the single domain response regulator SdrG and GSR-activating histidine kinases. Altogether, our findings indicate that the GSR in S. melonis Fr1 underlies a complex regulation to optimize resource allocation and resilience in stressful and changing environments.
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Affiliation(s)
- Lisa Gottschlich
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Petra Geiser
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Miriam Bortfeld-Miller
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Christopher M Field
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland.
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9
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Ren M, Feng X, Huang Y, Wang H, Hu Z, Clingenpeel S, Swan BK, Fonseca MM, Posada D, Stepanauskas R, Hollibaugh JT, Foster PG, Woyke T, Luo H. Phylogenomics suggests oxygen availability as a driving force in Thaumarchaeota evolution. ISME JOURNAL 2019; 13:2150-2161. [PMID: 31024152 DOI: 10.1038/s41396-019-0418-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 03/07/2019] [Accepted: 04/03/2019] [Indexed: 11/09/2022]
Abstract
Ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread in marine and terrestrial habitats, playing a major role in the global nitrogen cycle. However, their evolutionary history remains unexplored, which limits our understanding of their adaptation mechanisms. Here, our comprehensive phylogenomic tree of Thaumarchaeota supports three sequential events: origin of AOA from terrestrial non-AOA ancestors, colonization of the shallow ocean, and expansion to the deep ocean. Careful molecular dating suggests that these events coincided with the Great Oxygenation Event around 2300 million years ago (Mya), and oxygenation of the shallow and deep ocean around 800 and 635-560 Mya, respectively. The first transition was likely enabled by the gain of an aerobic pathway for energy production by ammonia oxidation and biosynthetic pathways for cobalamin and biotin that act as cofactors in aerobic metabolism. The first transition was also accompanied by the loss of dissimilatory nitrate and sulfate reduction, loss of oxygen-sensitive pyruvate oxidoreductase, which reduces pyruvate to acetyl-CoA, and loss of the Wood-Ljungdahl pathway for anaerobic carbon fixation. The second transition involved gain of a K+ transporter and of the biosynthetic pathway for ectoine, which may function as an osmoprotectant. The third transition was accompanied by the loss of the uvr system for repairing ultraviolet light-induced DNA lesions. We conclude that oxygen availability drove the terrestrial origin of AOA and their expansion to the photic and dark oceans, and that the stressors encountered during these events were partially overcome by gene acquisitions from Euryarchaeota and Bacteria, among other sources.
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Affiliation(s)
- Minglei Ren
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong.,Shenzhen Research Institute, The Chinese University of Hong Kong, 518000, Shenzhen, China
| | - Xiaoyuan Feng
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yongjie Huang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong.,Shenzhen Research Institute, The Chinese University of Hong Kong, 518000, Shenzhen, China
| | - Hui Wang
- Biology Department, College of Science, Shantou University, 515063, Shantou, China
| | - Zhong Hu
- Biology Department, College of Science, Shantou University, 515063, Shantou, China
| | | | - Brandon K Swan
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA.,National Biodefense Analysis and Countermeasures Center, Frederick, MD, 21702, USA
| | - Miguel M Fonseca
- CINBIO and Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain
| | - David Posada
- CINBIO and Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain
| | | | - James T Hollibaugh
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Peter G Foster
- Department of Life Sciences, Natural History Museum, London, SW7 5BD, UK
| | - Tanja Woyke
- DOE Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong. .,Shenzhen Research Institute, The Chinese University of Hong Kong, 518000, Shenzhen, China.
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10
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Williams SM, Chatterji D. Flexible aspartates propel iron to the ferroxidation sites along pathways stabilized by a conserved arginine in Dps proteins from Mycobacterium smegmatis. Metallomics 2018; 9:685-698. [PMID: 28418062 DOI: 10.1039/c7mt00008a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
DNA-binding proteins under starvation (Dps) are dodecameric nano-compartments for iron oxidation and storage in bacterial cells. These proteins have roughly spherical structures with a hollow interior where iron is stored. Through mutational analysis of a conserved arginine residue in the second Dps protein from Mycobacterium smegmatis, we have identified residues which stabilize the interfaces between the iron entry and ferroxidation sites. Also, we have used X-ray crystallography to determine the structures of co-crystals of iron and Dps in varying proportions and compare the changes in these ligand-bound forms with respect to the apo-protein. The iron-loaded proteins of low, medium and high iron-bound forms were found to exhibit aspartate residues with alternate conformations, some of which could be directly linked to the sites of ferroxidation and iron entry. We conclude that the increased flexibility of aspartates in the presence of iron facilitates its movement from the entry site to the ferroxidaton site, and the two active sites are stabilized by the interactions of a conserved arginine residue R73.
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11
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Tsai KYD, Chang IJ. Oxidation of Bromide to Bromine by Ruthenium(II) Bipyridine-Type Complexes Using the Flash-Quench Technique. Inorg Chem 2017; 56:8497-8503. [DOI: 10.1021/acs.inorgchem.7b01238] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kelvin Yun-Da Tsai
- Department of Chemistry, National Taiwan Normal University, 88 Tingchow Road, Section 4, Taipei 11677 Taiwan
| | - I-Jy Chang
- Department of Chemistry, National Taiwan Normal University, 88 Tingchow Road, Section 4, Taipei 11677 Taiwan
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12
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Williams TJ, Liao Y, Ye J, Kuchel RP, Poljak A, Raftery MJ, Cavicchioli R. Cold adaptation of the Antarctic haloarchaea
Halohasta litchfieldiae
and
Halorubrum lacusprofundi. Environ Microbiol 2017; 19:2210-2227. [DOI: 10.1111/1462-2920.13705] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/17/2017] [Accepted: 02/08/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Timothy J. Williams
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydney New South Wales2052 Australia
| | - Yan Liao
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydney New South Wales2052 Australia
| | - Jun Ye
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydney New South Wales2052 Australia
- Centre for Marine Bio‐InnovationThe University of New South WalesSydney New South Wales2052 Australia
| | - Rhiannon P. Kuchel
- Electron Microscopy UnitThe University of New South WalesSydney New South Wales2052 Australia
| | - Anne Poljak
- Bioanalytical Mass Spectrometry FacilityThe University of New South WalesSydney New South Wales2052 Australia
| | - Mark J. Raftery
- Bioanalytical Mass Spectrometry FacilityThe University of New South WalesSydney New South Wales2052 Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydney New South Wales2052 Australia
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13
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Turner AG, Ong CLY, Walker MJ, Djoko KY, McEwan AG. Transition Metal Homeostasis in Streptococcus pyogenes and Streptococcus pneumoniae. Adv Microb Physiol 2017; 70:123-191. [PMID: 28528647 DOI: 10.1016/bs.ampbs.2017.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Trace metals such as Fe, Mn, Zn and Cu are essential for various biological functions including proper innate immune function. The host immune system has complicated and coordinated mechanisms in place to either starve and/or overload invading pathogens with various metals to combat the infection. Here, we discuss the roles of Fe, Mn and Zn in terms of nutritional immunity, and also the roles of Cu and Zn in metal overload in relation to the physiology and pathogenesis of two human streptococcal species, Streptococcus pneumoniae and Streptococcus pyogenes. S. pneumoniae is a major human pathogen that is carried asymptomatically in the nasopharynx by up to 70% of the population; however, transition to internal sites can cause a range of diseases such as pneumonia, otitis media, meningitis and bacteraemia. S. pyogenes is a human pathogen responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Both species have overlapping capacity with respect to metal acquisition, export and regulation and how metal homeostasis relates to their virulence and ability to invade and survive within the host. It is becoming more apparent that metals have an important role to play in the control of infection, and with further investigations, it could lead to the potential use of metals in novel antimicrobial therapies.
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Affiliation(s)
- Andrew G Turner
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Cheryl-Lynn Y Ong
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Karrera Y Djoko
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.
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14
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Zhu Z, Peng M, Zhang J, Tan L. Interaction of octahedral ruthenium(II) polypyridyl complex [Ru(bpy) 2(PIP)] 2+ with poly(U)·poly(A)*poly(U) triplex: Increasing third-strand stabilization of the triplex without affecting the stability of the duplex. J Inorg Biochem 2017; 169:44-49. [PMID: 28104569 DOI: 10.1016/j.jinorgbio.2017.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 01/10/2023]
Abstract
Triple-helical RNA are of interest because of possible biological roles as well as the potential therapeutic uses of these structures, while the stability of triplexes is usually weaker than that of the Watson-Crick base pairing duplex strand due to the electrostatic repulsion between three polyanionic strands. Therefore, how to increase the stability of the specific sequences of triplexes are of importance. In this paper the binding of a Ru(II) complex, [Ru(bpy)2(PIP)]2+ (bpy=2.2'-bipyridine, PIP=2-phenyl-1H-imidazo[4,5-f]- [1,10]-phenanthroline), with poly(U)·poly(A)*poly(U) triplex has been investigated by spectrophotometry, spectrofluorometry, viscosimetry and circular dichroism. The results suggest that [Ru(bpy)2(PIP)]2+ as a metallointercalator can stabilize poly(U)·poly(A)*poly(U) triplex (where · denotes the Watson-Crick base pairing and * denotes the Hoogsteen base pairing),while it stabilizes third-strand with no obvious effect on the duplex of poly(U)·poly(A), reflecting the binding of this complex with the triplex is favored by the Hoogsteen paired poly(U) third strand to a great extent.
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Affiliation(s)
- Zhiyuan Zhu
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Mengna Peng
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Jingwen Zhang
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, PR China.
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15
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Arnold AR, Grodick MA, Barton JK. DNA Charge Transport: from Chemical Principles to the Cell. Cell Chem Biol 2016; 23:183-197. [PMID: 26933744 DOI: 10.1016/j.chembiol.2015.11.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 11/30/2022]
Abstract
The DNA double helix has captured the imagination of many, bringing it to the forefront of biological research. DNA has unique features that extend our interest into areas of chemistry, physics, material science, and engineering. Our laboratory has focused on studies of DNA charge transport (CT), wherein charges can efficiently travel long molecular distances through the DNA helix while maintaining an exquisite sensitivity to base pair π-stacking. Because DNA CT chemistry reports on the integrity of the DNA duplex, this property may be exploited to develop electrochemical devices to detect DNA lesions and DNA-binding proteins. Furthermore, studies now indicate that DNA CT may also be used in the cell by, for example, DNA repair proteins, as a cellular diagnostic, in order to scan the genome to localize efficiently to damage sites. In this review, we describe this evolution of DNA CT chemistry from the discovery of fundamental chemical principles to applications in diagnostic strategies and possible roles in biology.
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Affiliation(s)
- Anna R Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael A Grodick
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jacqueline K Barton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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16
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Abstract
Biological electron transfer reactions between metal cofactors are critical to many essential processes within the cell. Duplex DNA is, moreover, capable of mediating the transport of charge through its π-stacked nitrogenous bases. Increasingly, [4Fe4S] clusters, generally redox-active cofactors, have been found to be associated with enzymes involved in DNA processing. DNA-binding enzymes containing [4Fe4S] clusters can thus utilize DNA charge transport (DNA CT) for redox signaling to coordinate reactions over long molecular distances. In particular, DNA CT signaling may represent the first step in the search for DNA lesions by proteins containing [4Fe4S] clusters that are involved in DNA repair. Here we describe research carried out to examine the chemical characteristics and biological consequences of DNA CT. We are finding that DNA CT among metalloproteins represents powerful chemistry for redox signaling at long range within the cell.
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Affiliation(s)
- Elizabeth O’Brien
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena CA 91125
| | - Rebekah M.B. Silva
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena CA 91125
| | - Jacqueline K. Barton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena CA 91125
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17
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Arnold AR, Zhou A, Barton JK. Characterization of the DNA-Mediated Oxidation of Dps, A Bacterial Ferritin. J Am Chem Soc 2016; 138:11290-8. [PMID: 27571139 DOI: 10.1021/jacs.6b06507] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dps proteins are bacterial ferritins that protect DNA from oxidative stress and have been implicated in bacterial survival and virulence. In addition to direct oxidation of the Dps iron sites by diffusing oxidants, oxidation from a distance via DNA charge transport (CT), where electrons and electron holes are rapidly transported through the base-pair π-stack, could represent an efficient DNA protection mechanism utilized by Dps. Here, we spectroscopically characterize the DNA-mediated oxidation of ferrous iron-loaded Dps. X-band EPR was used to monitor the oxidation of DNA-bound Dps after DNA photooxidation using an intercalating ruthenium photooxidant and the flash-quench technique. Upon irradiation with poly(dGdC)2, a signal arises with g = 4.3, consistent with the formation of mononuclear high-spin Fe(III) sites of low symmetry, the expected oxidation product of Dps with one iron bound at each ferroxidase site. When poly(dGdC)2 is substituted with poly(dAdT)2, the yield of Dps oxidation is decreased significantly, consistent with guanine radical intermediates facilitating Dps oxidation. We have also explored possible protein electron transfer (ET) intermediates in the DNA-mediated oxidation of ferrous iron-loaded Dps. Dps proteins contain a conserved tryptophan residue in close proximity to the iron-binding ferroxidase site (W52 in E. coli Dps). In EPR studies of the oxidation of ferrous iron-loaded Dps following DNA photooxidation, a W52A Dps mutant was significantly deficient compared to WT Dps in forming the characteristic EPR signal at g = 4.3, consistent with W52 acting as an ET hopping intermediate. This effect is mirrored in vivo in E. coli survival in response to hydrogen peroxide, where mutation of W52 leads to decreased survival under oxidative stress.
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Affiliation(s)
- Anna R Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Andy Zhou
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Jacqueline K Barton
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
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18
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Ushijima Y, Yoshida O, Villanueva MJA, Ohniwa RL, Morikawa K. Nucleoid clumping is dispensable for the Dps-dependent hydrogen peroxide resistance in Staphylococcus aureus. MICROBIOLOGY-SGM 2016; 162:1822-1828. [PMID: 27539241 DOI: 10.1099/mic.0.000353] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dps family proteins have the ferroxidase activity that contributes to oxidative stress resistance. In addition, a part of Dps family proteins including Escherichia coli Dps and Staphylococcus aureus MrgA (metallo regulon gene A) bind DNA and induce the structural change of the nucleoid. We previously showed that a mutated MrgA with reduced ferroxidase activity was unable to contribute to the hydrogen peroxide (H2O2) and UV resistance in S. aureus, suggesting that the nucleoid clumping by MrgA is not sufficient for the resistance. However, it remained elusive whether the nucleoid clumping is dispensable for the resistance. Here, we aimed to clarify this question by employing the E. coli Dps lacking DNA-binding activity, DpsΔ18. Staphylococcal nucleoid was clumped by E. coli Dps, but not by DpsΔ18. H2O2 stress assay indicated that Dps and DpsΔ18 restored the reduced susceptibility of S. aureus ΔmrgA. Thus, we concluded that the staphylococcal nucleoid clumping is dispensable for the Dps-mediated H2O2 resistance. In contrast, Dps was unable to complement S. aureus ΔmrgA in the UV resistance, suggesting the MrgA function that cannot be compensated for by E. coli Dps.
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Affiliation(s)
- Yuri Ushijima
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Osamu Yoshida
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
| | | | - Ryosuke L Ohniwa
- Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.,Center for Biotechnology, National Taiwan University, Taipei 10617, Taiwan, ROC
| | - Kazuya Morikawa
- Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
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19
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Hosseinzadeh P, Lu Y. Design and fine-tuning redox potentials of metalloproteins involved in electron transfer in bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:557-581. [PMID: 26301482 PMCID: PMC4761536 DOI: 10.1016/j.bbabio.2015.08.006] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/20/2015] [Indexed: 12/25/2022]
Abstract
Redox potentials are a major contributor in controlling the electron transfer (ET) rates and thus regulating the ET processes in the bioenergetics. To maximize the efficiency of the ET process, one needs to master the art of tuning the redox potential, especially in metalloproteins, as they represent major classes of ET proteins. In this review, we first describe the importance of tuning the redox potential of ET centers and its role in regulating the ET in bioenergetic processes including photosynthesis and respiration. The main focus of this review is to summarize recent work in designing the ET centers, namely cupredoxins, cytochromes, and iron-sulfur proteins, and examples in design of protein networks involved these ET centers. We then discuss the factors that affect redox potentials of these ET centers including metal ion, the ligands to metal center and interactions beyond the primary ligand, especially non-covalent secondary coordination sphere interactions. We provide examples of strategies to fine-tune the redox potential using both natural and unnatural amino acids and native and nonnative cofactors. Several case studies are used to illustrate recent successes in this area. Outlooks for future endeavors are also provided. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
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Affiliation(s)
- Parisa Hosseinzadeh
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews St., Urbana, IL, 61801, USA
| | - Yi Lu
- Department of Chemistry and Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews St., Urbana, IL, 61801, USA.
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20
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Sanchuki HBS, Valdameri G, Moure VR, Rodriguez JA, Pedrosa FO, Souza EM, Korolik V, Ribeiro RR, Huergo LF. Conserved histidine residues at the ferroxidase centre of the Campylobacter jejuni Dps protein are not strictly required for metal binding and oxidation. MICROBIOLOGY-SGM 2015; 162:156-163. [PMID: 26555736 DOI: 10.1099/mic.0.000210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Iron is an essential micronutrient for living organisms as it is involved in a broad variety of important biological processes. However, free iron inside the cell could be potentially toxic, generating hydroxyl radicals through the Fenton reaction. Dps (DNA-binding protein from starved cells) belongs to a subfamily of ferritins and can store iron atoms inside the dodecamer. The presence of a ferroxidase centre, composed of highly conserved residues, is a signature of this protein family. In this study, we analysed the role of two conserved histidine residues (H25 and H37) located at the ferroxidase centre of the Campylobacter jejuni Dps protein by replacing them with glycine residues. The C. jejuni H25G/H37G substituted variant showed reduced iron binding and ferroxidase activities in comparison with wt Dps, while DNA-binding activity remained unaffected. We also found that both CjDps wt and CjDps H25G/H37G were able to bind manganese atoms. These results indicate that the H25 and H37 residues at the ferroxidase centre of C. jejuni Dps are not strictly required for metal binding and oxidation.
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Affiliation(s)
- Heloisa B S Sanchuki
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Glaucio Valdameri
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Vivian R Moure
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Jorge A Rodriguez
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Guadalajara, Mexico
| | - Fábio O Pedrosa
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Emanuel M Souza
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Victoria Korolik
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | | | - Luciano F Huergo
- Setor Litoral, UFPR, Matinhos, PR, Brazil.,Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
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21
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Paleček E, Tkáč J, Bartošík M, Bertók T, Ostatná V, Paleček J. Electrochemistry of nonconjugated proteins and glycoproteins. Toward sensors for biomedicine and glycomics. Chem Rev 2015; 115:2045-108. [PMID: 25659975 PMCID: PMC4360380 DOI: 10.1021/cr500279h] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 02/07/2023]
Affiliation(s)
- Emil Paleček
- Institute
of Biophysics Academy of Science of the Czech Republic, v.v.i., Královopolská
135, 612 65 Brno, Czech Republic
| | - Jan Tkáč
- Institute
of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovakia
| | - Martin Bartošík
- Regional
Centre for Applied Molecular Oncology, Masaryk
Memorial Cancer Institute, Žlutý kopec 7, 656 53 Brno, Czech Republic
| | - Tomáš Bertók
- Institute
of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovakia
| | - Veronika Ostatná
- Institute
of Biophysics Academy of Science of the Czech Republic, v.v.i., Královopolská
135, 612 65 Brno, Czech Republic
| | - Jan Paleček
- Central
European Institute of Technology, Masaryk
University, Kamenice
5, 625 00 Brno, Czech Republic
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22
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Abstract
The unique characteristics of DNA charge transport (CT) have prompted an examination of roles for this chemistry within a biological context. Not only can DNA CT facilitate long-range oxidative damage of DNA, but redox-active proteins can couple to the DNA base stack and participate in long-range redox reactions using DNA CT. DNA transcription factors with redox-active moieties such as SoxR and p53 can use DNA CT as a form of redox sensing. DNA CT chemistry also provides a means to monitor the integrity of the DNA, given the sensitivity of DNA CT to perturbations in base stacking as arise with mismatches and lesions. Enzymes that utilize this chemistry include an interesting and ever-growing class of DNA-processing enzymes involved in DNA repair, replication, and transcription that have been found to contain 4Fe-4S clusters. DNA repair enzymes containing 4Fe-4S clusters, that include endonuclease III (EndoIII), MutY, and DinG from bacteria, as well as XPD from archaea, have been shown to be redox-active when bound to DNA, share a DNA-bound redox potential, and can be reduced and oxidized at long-range via DNA CT. Interactions between DNA and these proteins in solution, in addition to genetics experiments within Escherichia coli, suggest that DNA-mediated CT can be used as a means of cooperative signaling among DNA repair proteins that contain 4Fe-4S clusters as a first step in finding DNA damage, even within cells. On the basis of these data, we can consider also how DNA-mediated CT may be used as a means of signaling to coordinate DNA processing across the genome.
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Affiliation(s)
- Michael A Grodick
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
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23
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Li J, Sun Y, Xie L, He X, Tan L. Effect of ancillary ligands on the interaction of ruthenium(II) complexes with the triplex RNA poly(U)·poly(A)*poly(U). J Inorg Biochem 2014; 143:56-63. [PMID: 25528478 DOI: 10.1016/j.jinorgbio.2014.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/03/2014] [Accepted: 12/03/2014] [Indexed: 01/01/2023]
Abstract
Two new Ru(II) complexes with 1,8-naphthalimide group, [Ru(phen)2(pnip)](2+) (Ru1; phen=1,10-phenanthroline, pnip=2-[N-(p-phenyl)-1,8-napthalimide]imidazo[4',5'-f][1,10]phenanthroline) and [Ru(bpy)2(pnip)](2+) (Ru2; bpy=2,2'-bipyridine), have been synthesized and characterized. The interactions of Ru1 and Ru2 with the triplex RNA poly(U)•poly(A)*poly(U) (where • denotes the Watson-Crick base pairing and * denotes the Hoogsteen base pairing) were studied by various biophysical. Electronic spectra established that the binding affinity for Ru1 was greater than that for Ru2. Fluorescence and viscosity studies gave convincing evidence for a true intercalative binding of both complexes with the RNA triplex. UV melting studies confirmed that the two complexes could stabilize the triplex, whereas the effects of the two complexes on the stability of the Hoogsteen base-paired strand ploy(U) and the Watson-Crick base-paired duplex poly(U)•poly(A) of the triplex were different. In the case of Ru1, the increase of the thermal stability of the Hoogsteen base-paired strand was stronger than that of the Watson-Crick base-paired duplex. However, an opposite effect was observed in the case of Ru2. Circular dichroic studies suggested that the RNA triplex undergoes a conformational transition in the presence of Ru1, whereas the helicity of the RNA triplex still remains A-type in the presence of Ru2. The main results obtained here further advance our knowledge on the interaction of RNA triple-stranded structures with metal complexes, particularly ruthenium(II) complexes.
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Affiliation(s)
- Jia Li
- College of Chemistry, Xiangtan University, Xiangtan, PR China
| | - Yanmei Sun
- College of Chemistry, Xiangtan University, Xiangtan, PR China
| | - Lingjun Xie
- College of Chemistry, Xiangtan University, Xiangtan, PR China
| | - Xiaojun He
- College of Chemistry, Xiangtan University, Xiangtan, PR China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, PR China.
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24
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Ushijima Y, Ohniwa RL, Maruyama A, Saito S, Tanaka Y, Morikawa K. Nucleoid compaction by MrgA(Asp56Ala/Glu60Ala) does not contribute to staphylococcal cell survival against oxidative stress and phagocytic killing by macrophages. FEMS Microbiol Lett 2014; 360:144-51. [PMID: 25227518 DOI: 10.1111/1574-6968.12598] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 08/28/2014] [Accepted: 09/09/2014] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus MrgA (encoded by mrgA) belongs to the Dps family of proteins, which play important roles in coping with various stresses. The staphylococcal mrgA gene is specifically expressed under oxidative stress conditions and is one of the most highly induced genes during phagocytic killing by macrophages. We previously reported that mrgA is essential for oxidative stress resistance, and can cause nucleoid compaction. However, whether nucleoid compaction by itself would contribute to oxidative stress resistance was hard to determine, because Dps family proteins generally have ferroxidase activity to prevent hydroxyl radical formation via the Fenton reaction. In this study, we resolved the crystal structure of MrgA and conducted mutation analysis of Asp56 and Glu60, which are located at the expected ferroxidase centre. In the strain expressing Asp56Ala/Glu60Ala MrgA (termed MrgA*), MrgA* retained dodecamer formation and nucleoid compaction ability. By contrast, the ferroxidase activity of MrgA* decreased by about half. Viability of the mrgA* strain was as low as the mrgA null mutant in oxidative stress and phagocytic killing assays. These results suggest that nucleoid compaction by itself is insufficient for oxidative stress resistance, and Asp56 and Glu60 constitute essential molecular sites in MrgA for oxidative stress resistance and survival against phagocytic killing.
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Affiliation(s)
- Yuri Ushijima
- Graduate School of Comprehensive Human Science, University of Tsukuba, Tsukuba, Japan
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