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Bimai O, Banerjee I, Rozman Grinberg I, Huang P, Hultgren L, Ekström S, Lundin D, Sjöberg BM, Logan DT. Nucleotide binding to the ATP-cone in anaerobic ribonucleotide reductases allosterically regulates activity by modulating substrate binding. eLife 2024; 12:RP89292. [PMID: 38968292 PMCID: PMC11226230 DOI: 10.7554/elife.89292] [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] [Indexed: 07/07/2024] Open
Abstract
A small, nucleotide-binding domain, the ATP-cone, is found at the N-terminus of most ribonucleotide reductase (RNR) catalytic subunits. By binding adenosine triphosphate (ATP) or deoxyadenosine triphosphate (dATP) it regulates the enzyme activity of all classes of RNR. Functional and structural work on aerobic RNRs has revealed a plethora of ways in which dATP inhibits activity by inducing oligomerisation and preventing a productive radical transfer from one subunit to the active site in the other. Anaerobic RNRs, on the other hand, store a stable glycyl radical next to the active site and the basis for their dATP-dependent inhibition is completely unknown. We present biochemical, biophysical, and structural information on the effects of ATP and dATP binding to the anaerobic RNR from Prevotella copri. The enzyme exists in a dimer-tetramer equilibrium biased towards dimers when two ATP molecules are bound to the ATP-cone and tetramers when two dATP molecules are bound. In the presence of ATP, P. copri NrdD is active and has a fully ordered glycyl radical domain (GRD) in one monomer of the dimer. Binding of dATP to the ATP-cone results in loss of activity and increased dynamics of the GRD, such that it cannot be detected in the cryo-EM structures. The glycyl radical is formed even in the dATP-bound form, but the substrate does not bind. The structures implicate a complex network of interactions in activity regulation that involve the GRD more than 30 Å away from the dATP molecules, the allosteric substrate specificity site and a conserved but previously unseen flap over the active site. Taken together, the results suggest that dATP inhibition in anaerobic RNRs acts by increasing the flexibility of the flap and GRD, thereby preventing both substrate binding and radical mobilisation.
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Affiliation(s)
- Ornella Bimai
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Ipsita Banerjee
- Section for Biochemistry and Structural Biology, Centre for Molecular Protein Science, Department of Chemistry, Lund UniversityLundSweden
| | | | - Ping Huang
- Department of Chemistry - Ångström Laboratory, Uppsala UniversityUppsalaSweden
| | - Lucas Hultgren
- Structural Proteomics, SciLifeLab, Lund UniversityLundSweden
| | - Simon Ekström
- Structural Proteomics, SciLifeLab, Lund UniversityLundSweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Derek T Logan
- Section for Biochemistry and Structural Biology, Centre for Molecular Protein Science, Department of Chemistry, Lund UniversityLundSweden
- Cryo-EM for Life Science, SciLifeLab, Lund UniversityLundSweden
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2
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Song DY, Stubbe J, Nocera DG. Protein engineering a PhotoRNR chimera based on a unifying evolutionary apparatus among the natural classes of ribonucleotide reductases. Proc Natl Acad Sci U S A 2024; 121:e2317291121. [PMID: 38648489 PMCID: PMC11067019 DOI: 10.1073/pnas.2317291121] [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: 10/05/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Ribonucleotide reductases (RNRs) are essential enzymes that catalyze the de novo transformation of nucleoside 5'-di(tri)phosphates [ND(T)Ps, where N is A, U, C, or G] to their corresponding deoxynucleotides. Despite the diversity of factors required for function and the low sequence conservation across RNRs, a unifying apparatus consolidating RNR activity is explored. We combine aspects of the protein subunit simplicity of class II RNR with a modified version of Escherichia coli class la photoRNRs that initiate radical chemistry with light to engineer a mimic of a class II enzyme. The design of this RNR involves fusing a truncated form of the active site containing α subunit with the functionally important C-terminal tail of the radical-generating β subunit to render a chimeric RNR. Inspired by a recent cryo-EM structure, a [Re] photooxidant is located adjacent to Y356[β], which is an essential component of the radical transport pathway in class I RNRs. Combination of this RNR photochimera with cytidine diphosphate (CDP), adenosine triphosphate (ATP), and light resulted in the generation of Y356• along with production of deoxycytidine diphosphate (dCDP) and cytosine. The photoproducts reflect an active site chemistry consistent with both the consensus mechanism of RNR and chemistry observed when RNR is inactivated by mechanism-based inhibitors in the active site. The enzymatic activity of the RNR photochimera in the absence of any β metallocofactor highlights the adaptability of the 10-stranded αβ barrel finger loop to support deoxynucleotide formation and accommodate the design of engineered RNRs.
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Affiliation(s)
- David Y. Song
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA02138
| | - JoAnne Stubbe
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA02138
| | - Daniel G. Nocera
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA02138
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3
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Tozzi A, Mazzeo M. The First Nucleic Acid Strands May Have Grown on Peptides via Primeval Reverse Translation. Acta Biotheor 2023; 71:23. [PMID: 37947915 DOI: 10.1007/s10441-023-09474-6] [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: 04/05/2023] [Accepted: 10/25/2023] [Indexed: 11/12/2023]
Abstract
The central dogma of molecular biology dictates that, with only a few exceptions, information proceeds from DNA to protein through an RNA intermediate. Examining the enigmatic steps from prebiotic to biological chemistry, we take another road suggesting that primordial peptides acted as template for the self-assembly of the first nucleic acids polymers. Arguing in favour of a sort of archaic "reverse translation" from proteins to RNA, our basic premise is a Hadean Earth where key biomolecules such as amino acids, polypeptides, purines, pyrimidines, nucleosides and nucleotides were available under different prebiotically plausible conditions, including meteorites delivery, shallow ponds and hydrothermal vents scenarios. Supporting a protein-first scenario alternative to the RNA world hypothesis, we propose the primeval occurrence of short two-dimensional peptides termed "selective amino acid- and nucleotide-matching oligopeptides" (henceforward SANMAOs) that noncovalently bind at the same time the polymerized amino acids and the single nucleotides dispersed in the prebiotic milieu. In this theoretical paper, we describe the chemical features of this hypothetical oligopeptide, its biological plausibility and its virtues from an evolutionary perspective. We provide a theoretical example of SANMAO's selective pairing between amino acids and nucleosides, simulating a poly-Glycine peptide that acts as a template to build a purinic chain corresponding to the glycine's extant triplet codon GGG. Further, we discuss how SANMAO might have endorsed the formation of low-fidelity RNA's polymerized strains, well before the appearance of the accurate genetic material's transmission ensured by the current translation apparatus.
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Affiliation(s)
- Arturo Tozzi
- Center for Nonlinear Science, Department of Physics, University of North Texas, 1155 Union Circle, #311427, Denton, TX, 76203-5017, USA.
| | - Marco Mazzeo
- Erredibi Srl, Via Pazzigno 117, 80146, Naples, Italy
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4
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Wu LY, Piedade GJ, Moore RM, Harrison AO, Martins AM, Bidle KD, Polson SW, Sakowski EG, Nissimov JI, Dums JT, Ferrell BD, Wommack KE. Ubiquitous, B 12-dependent virioplankton utilizing ribonucleotide-triphosphate reductase demonstrate interseasonal dynamics and associate with a diverse range of bacterial hosts in the pelagic ocean. ISME COMMUNICATIONS 2023; 3:108. [PMID: 37789093 PMCID: PMC10547690 DOI: 10.1038/s43705-023-00306-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 10/05/2023]
Abstract
Through infection and lysis of their coexisting bacterial hosts, viruses impact the biogeochemical cycles sustaining globally significant pelagic oceanic ecosystems. Currently, little is known of the ecological interactions between lytic viruses and their bacterial hosts underlying these biogeochemical impacts at ecosystem scales. This study focused on populations of lytic viruses carrying the B12-dependent Class II monomeric ribonucleotide reductase (RNR) gene, ribonucleotide-triphosphate reductase (Class II RTPR), documenting seasonal changes in pelagic virioplankton and bacterioplankton using amplicon sequences of Class II RTPR and the 16S rRNA gene, respectively. Amplicon sequence libraries were analyzed using compositional data analysis tools that account for the compositional nature of these data. Both virio- and bacterioplankton communities responded to environmental changes typically seen across seasonal cycles as well as shorter term upwelling-downwelling events. Defining Class II RTPR-carrying viral populations according to major phylogenetic clades proved a more robust means of exploring virioplankton ecology than operational taxonomic units defined by percent sequence homology. Virioplankton Class II RTPR populations showed positive associations with a broad phylogenetic diversity of bacterioplankton including dominant taxa within pelagic oceanic ecosystems such as Prochlorococcus and SAR11. Temporal changes in Class II RTPR virioplankton, occurring as both free viruses and within infected cells, indicated possible viral-host pairs undergoing sustained infection and lysis cycles throughout the seasonal study. Phylogenetic relationships inferred from Class II RTPR sequences mirrored ecological patterns in virio- and bacterioplankton populations demonstrating possible genome to phenome associations for an essential viral replication gene.
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Affiliation(s)
- Ling-Yi Wu
- Theoretical Biology and Bioinformatics, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, the Netherlands
| | - Gonçalo J Piedade
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797 SZ, t'Horntje, The Netherlands
- Department of Oceanography and Fisheries and Ocean Sciences Institute-OKEANOS, University of the Azores, 9901-862 Horta, Faial, Azores, Portugal
| | - Ryan M Moore
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA
| | - Amelia O Harrison
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA
| | - Ana M Martins
- Department of Oceanography and Fisheries and Ocean Sciences Institute-OKEANOS, University of the Azores, 9901-862 Horta, Faial, Azores, Portugal
| | - Kay D Bidle
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ, 08901, USA
| | - Shawn W Polson
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA
| | - Eric G Sakowski
- Department of Earth Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Jozef I Nissimov
- Department of Biology, University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada
| | - Jacob T Dums
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA
- Biotechnology Program, North Carolina State University, 2800 Faucette Dr, Raleigh, NC, 27695, USA
| | - Barbra D Ferrell
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA
| | - K Eric Wommack
- Delaware Biotechnology Institute, University of Delaware, 590 Avenue 1743, Newark, DE, 19713, USA.
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Wozniak K, Brzezinski K. Biological Catalysis and Information Storage Have Relied on N-Glycosyl Derivatives of β-D-Ribofuranose since the Origins of Life. Biomolecules 2023; 13:biom13050782. [PMID: 37238652 DOI: 10.3390/biom13050782] [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: 03/06/2023] [Revised: 04/24/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
Most naturally occurring nucleotides and nucleosides are N-glycosyl derivatives of β-d-ribose. These N-ribosides are involved in most metabolic processes that occur in cells. They are essential components of nucleic acids, forming the basis for genetic information storage and flow. Moreover, these compounds are involved in numerous catalytic processes, including chemical energy production and storage, in which they serve as cofactors or coribozymes. From a chemical point of view, the overall structure of nucleotides and nucleosides is very similar and simple. However, their unique chemical and structural features render these compounds versatile building blocks that are crucial for life processes in all known organisms. Notably, the universal function of these compounds in encoding genetic information and cellular catalysis strongly suggests their essential role in the origins of life. In this review, we summarize major issues related to the role of N-ribosides in biological systems, especially in the context of the origin of life and its further evolution, through the RNA-based World(s), toward the life we observe today. We also discuss possible reasons why life has arisen from derivatives of β-d-ribofuranose instead of compounds based on other sugar moieties.
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Affiliation(s)
- Katarzyna Wozniak
- Department of Structural Biology of Prokaryotic Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-074 Poznan, Poland
| | - Krzysztof Brzezinski
- Department of Structural Biology of Prokaryotic Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-074 Poznan, Poland
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6
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Prognostic and Immunological Potential of Ribonucleotide Reductase Subunits in Liver Cancer. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2023; 2023:3878796. [PMID: 36713030 PMCID: PMC9883104 DOI: 10.1155/2023/3878796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 11/08/2022] [Accepted: 11/30/2022] [Indexed: 01/21/2023]
Abstract
Background Ribonucleotide reductase (RR) consists of two subunits, the large subunit RRM1 and the small subunit (RRM2 or RRM2B), which is essential for DNA replication. Dysregulations of RR were implicated in multiple types of cancer. However, the abnormal expressions and biologic functions of RR subunits in liver cancer remain to be elucidated. Methods TCGA, HCCDB, CCLE, HPA, cBioPortal, and GeneMANIA were utilized to perform bioinformatics analysis of RR subunits in the liver cancer. GO, KEGG, and GSEA were used for enrichment analysis. Results The expressions of RRM1, RRM2, and RRM2B were remarkably upregulated among liver cancer tissue both in mRNA and protein levels. High expression of RRM1 and RRM2 was notably associated with high tumor grade, high stage, short overall survival, and disease-specific survival. Enrichment analyses indicated that RRM1 and RRM2 were related to DNA replication, cell cycle, regulation of nuclear division, DNA repair, and DNA recombination. Correlation analysis indicated that RRM1 and RRM2 were significantly associated with several subsets of immune cell, including Th2 cells, cytotoxic cells, and neutrophils. RRM2B expression was positively associated with immune score and stromal score. Chemosensitivity analysis revealed that sensitivity of nelarabine was positively associated with high expressions of RRM1 and RRM2. The sensitivity of rapamycin was positively associated with high expressions of RRM2B. Conclusion Our findings demonstrated high expression profiles of RR subunits in liver cancer, which may provide novel insights for predicting the poor prognosis and increased chemosensitivity of liver cancer in clinic.
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7
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Burnim AA, Spence MA, Xu D, Jackson CJ, Ando N. Comprehensive phylogenetic analysis of the ribonucleotide reductase family reveals an ancestral clade. eLife 2022; 11:79790. [PMID: 36047668 PMCID: PMC9531940 DOI: 10.7554/elife.79790] [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: 04/26/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022] Open
Abstract
Ribonucleotide reductases (RNRs) are used by all free-living organisms and many viruses to catalyze an essential step in the de novo biosynthesis of DNA precursors. RNRs are remarkably diverse by primary sequence and cofactor requirement, while sharing a conserved fold and radical-based mechanism for nucleotide reduction. Here, we structurally aligned the diverse RNR family by the conserved catalytic barrel to reconstruct the first large-scale phylogeny consisting of 6779 sequences that unites all extant classes of the RNR family and performed evo-velocity analysis to independently validate our evolutionary model. With a robust phylogeny in-hand, we uncovered a novel, phylogenetically distinct clade that is placed as ancestral to the classes I and II RNRs, which we have termed clade Ø. We employed small-angle X-ray scattering (SAXS), cryogenic-electron microscopy (cryo-EM), and AlphaFold2 to investigate a member of this clade from Synechococcus phage S-CBP4 and report the most minimal RNR architecture to-date. Based on our analyses, we propose an evolutionary model of diversification in the RNR family and delineate how our phylogeny can be used as a roadmap for targeted future study. Billions of years ago, the Earth’s atmosphere had very little oxygen. It was only after some bacteria and early plants evolved to harness energy from sunlight that oxygen began to fill the Earth’s environment. Oxygen is highly reactive and can interfere with enzymes and other molecules that are essential to life. Organisms living at this point in history therefore had to adapt to survive in this new oxygen-rich world. An ancient family of enzymes known as ribonucleotide reductases are used by all free-living organisms and many viruses to repair and replicate their DNA. Because of their essential role in managing DNA, these enzymes have been around on Earth for billions of years. Understanding how they evolved could therefore shed light on how nature adapted to increasing oxygen levels and other environmental changes at the molecular level. One approach to study how proteins evolved is to use computational analysis to construct a phylogenetic tree. This reveals how existing members of a family are related to one another based on the chain of molecules (known as amino acids) that make up each protein. Despite having similar structures and all having the same function, ribonucleotide reductases have remarkably diverse sequences of amino acids. This makes it computationally very demanding to build a phylogenetic tree. To overcome this, Burnim, Spence, Xu et al. created a phylogenetic tree using structural information from a part of the enzyme that is relatively similar in many modern-day ribonucleotide reductases. The final result took seven continuous months on a supercomputer to generate, and includes over 6,000 members of the enzyme family. The phylogenetic tree revealed a new distinct group of ribonucleotide reductases that may explain how one adaptation to increasing levels of oxygen emerged in some family members, while another adaptation emerged in others. The approach used in this work also opens up a new way to study how other highly diverse enzymes and other protein families evolved, potentially revealing new insights about our planet’s past.
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Affiliation(s)
- Audrey A Burnim
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | - Matthew A Spence
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Da Xu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Nozomi Ando
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
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Fietze T, Wilk P, Kabinger F, Anoosheh S, Hofer A, Lundin D, Feiler CG, Weiss MS, Loderer C. HUG Domain Is Responsible for Active Dimer Stabilization in an NrdJd Ribonucleotide Reductase. Biochemistry 2022; 61:1633-1641. [PMID: 35856337 DOI: 10.1021/acs.biochem.2c00173] [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
Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to the corresponding deoxyribonucleotides. The catalytic activity of most RNRs depends on the formation of a dimer of the catalytic subunits. The active site is located at the interface, and part of the substrate binding site and regulatory mechanisms work across the subunit in the dimer. In this study, we describe and characterize a novel domain responsible for forming the catalytic dimer in several class II RNRs. The 3D structure of the class II RNR from Rhodobacter sphaeroides reveals a so far undescribed α-helical domain in the dimer interface, which is embracing the other subunit. Genetic removal of this HUG domain leads to a severe reduction of activity paired with reduced dimerization capability. In comparison with other described RNRs, the enzyme with this domain is less dependent on the presence of nucleotides to act as allosteric effectors in the formation of dimers. The HUG domain appears to serve as an interlock to keep the dimer intact and functional even at low enzyme and/or effector concentrations.
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Affiliation(s)
- Tobias Fietze
- Chair of Molecular Biotechnology, Technische Universität Dresden, Dresden 01217, Germany
| | - Piotr Wilk
- Macromolecular Crystallography, Helmholtz-Zentrum Berlin, Berlin 12489, Germany.,Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 31-007, Poland
| | - Florian Kabinger
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Saber Anoosheh
- Department of Medical Biochemistry, Umeå University, Umeå 1965, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry, Umeå University, Umeå 1965, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm 114 19, Sweden
| | - Christian G Feiler
- Macromolecular Crystallography, Helmholtz-Zentrum Berlin, Berlin 12489, Germany
| | - Manfred S Weiss
- Macromolecular Crystallography, Helmholtz-Zentrum Berlin, Berlin 12489, Germany
| | - Christoph Loderer
- Chair of Molecular Biotechnology, Technische Universität Dresden, Dresden 01217, Germany
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9
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Rozman Grinberg I, Martínez-Carranza M, Bimai O, Nouaïria G, Shahid S, Lundin D, Logan DT, Sjöberg BM, Stenmark P. A nucleotide-sensing oligomerization mechanism that controls NrdR-dependent transcription of ribonucleotide reductases. Nat Commun 2022; 13:2700. [PMID: 35577776 PMCID: PMC9110341 DOI: 10.1038/s41467-022-30328-1] [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: 09/20/2021] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractRibonucleotide reductase (RNR) is an essential enzyme that catalyzes the synthesis of DNA building blocks in virtually all living cells. NrdR, an RNR-specific repressor, controls the transcription of RNR genes and, often, its own, in most bacteria and some archaea. NrdR senses the concentration of nucleotides through its ATP-cone, an evolutionarily mobile domain that also regulates the enzymatic activity of many RNRs, while a Zn-ribbon domain mediates binding to NrdR boxes upstream of and overlapping the transcription start site of RNR genes. Here, we combine biochemical and cryo-EM studies of NrdR from Streptomyces coelicolor to show, at atomic resolution, how NrdR binds to DNA. The suggested mechanism involves an initial dodecamer loaded with two ATP molecules that cannot bind to DNA. When dATP concentrations increase, an octamer forms that is loaded with one molecule each of dATP and ATP per monomer. A tetramer derived from this octamer then binds to DNA and represses transcription of RNR. In many bacteria — including well-known pathogens such as Mycobacterium tuberculosis — NrdR simultaneously controls multiple RNRs and hence DNA synthesis, making it an excellent target for novel antibiotics development.
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10
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Bromberg Y, Aptekmann AA, Mahlich Y, Cook L, Senn S, Miller M, Nanda V, Ferreiro DU, Falkowski PG. Quantifying structural relationships of metal-binding sites suggests origins of biological electron transfer. SCIENCE ADVANCES 2022; 8:eabj3984. [PMID: 35030025 PMCID: PMC8759750 DOI: 10.1126/sciadv.abj3984] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 11/22/2021] [Indexed: 06/07/2023]
Abstract
Biological redox reactions drive planetary biogeochemical cycles. Using a novel, structure-guided sequence analysis of proteins, we explored the patterns of evolution of enzymes responsible for these reactions. Our analysis reveals that the folds that bind transition metal–containing ligands have similar structural geometry and amino acid sequences across the full diversity of proteins. Similarity across folds reflects the availability of key transition metals over geological time and strongly suggests that transition metal–ligand binding had a small number of common peptide origins. We observe that structures central to our similarity network come primarily from oxidoreductases, suggesting that ancestral peptides may have also facilitated electron transfer reactions. Last, our results reveal that the earliest biologically functional peptides were likely available before the assembly of fully functional protein domains over 3.8 billion years ago.Thus, life is a special, very complex form of motion of matter, but this form did not always exist, and it is not separated from inorganic nature by an impassable abyss; rather, it arose from inorganic nature as a new property in the process of evolution of the world. We must study the history of this evolution if we want to solve the problem of the origin of life. [A. I. Oparin (1)]
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Affiliation(s)
- Yana Bromberg
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ 08873, USA
| | - Ariel A. Aptekmann
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ 08873, USA
| | - Yannick Mahlich
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ 08873, USA
| | - Linda Cook
- Program in Applied and Computational Math, Princeton University, Princeton, NJ 08540, USA
| | - Stefan Senn
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ 08873, USA
| | - Maximillian Miller
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ 08873, USA
| | - Vikas Nanda
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, and Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ 08854, USA
| | - Diego U. Ferreiro
- Protein Physiology Lab, Departamento de Química Biológica, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paul G. Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA
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11
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Banerjee R, Srinivas V, Lebrette H. Ferritin-Like Proteins: A Conserved Core for a Myriad of Enzyme Complexes. Subcell Biochem 2022; 99:109-153. [PMID: 36151375 DOI: 10.1007/978-3-031-00793-4_4] [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] [Indexed: 06/16/2023]
Abstract
Ferritin-like proteins share a common fold, a four α-helix bundle core, often coordinating a pair of metal ions. Although conserved, the ferritin fold permits a diverse set of reactions, and is central in a multitude of macromolecular enzyme complexes. Here, we emphasize this diversity through three members of the ferritin-like superfamily: the soluble methane monooxygenase, the class I ribonucleotide reductase and the aldehyde deformylating oxygenase. They all rely on dinuclear metal cofactors to catalyze different challenging oxygen-dependent reactions through the formation of multi-protein complexes. Recent studies using cryo-electron microscopy, serial femtosecond crystallography at an X-ray free electron laser source, or single-crystal X-ray diffraction, have reported the structures of the active protein complexes, and revealed unprecedented insights into the molecular mechanisms of these three enzymes.
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Affiliation(s)
- Rahul Banerjee
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Vivek Srinivas
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Hugo Lebrette
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse, France.
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12
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Long MJC, Ly P, Aye Y. Still no Rest for the Reductases: Ribonucleotide Reductase (RNR) Structure and Function: An Update. Subcell Biochem 2022; 99:155-197. [PMID: 36151376 DOI: 10.1007/978-3-031-00793-4_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Herein we present a multidisciplinary discussion of ribonucleotide reductase (RNR), the essential enzyme uniquely responsible for conversion of ribonucleotides to deoxyribonucleotides. This chapter primarily presents an overview of this multifaceted and complex enzyme, covering RNR's role in enzymology, biochemistry, medicinal chemistry, and cell biology. It further focuses on RNR from mammals, whose interesting and often conflicting roles in health and disease are coming more into focus. We present pitfalls that we think have not always been dealt with by researchers in each area and further seek to unite some of the field-specific observations surrounding this enzyme. Our work is thus not intended to cover any one topic in extreme detail, but rather give what we consider to be the necessary broad grounding to understand this critical enzyme holistically. Although this is an approach we have advocated in many different areas of scientific research, there is arguably no other single enzyme that embodies the need for such broad study than RNR. Thus, we submit that RNR itself is a paradigm of interdisciplinary research that is of interest from the perspective of the generalist and the specialist alike. We hope that the discussions herein will thus be helpful to not only those wanting to tackle RNR-specific problems, but also those working on similar interdisciplinary projects centering around other enzymes.
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Affiliation(s)
- Marcus J C Long
- University of Lausanne (UNIL), Lausanne, Switzerland
- Department of Biochemistry, UNIL, Epalinges, Switzerland
| | - Phillippe Ly
- Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- EPFL SB ISIC LEAGO, Lausanne, Switzerland
| | - Yimon Aye
- Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
- EPFL SB ISIC LEAGO, Lausanne, Switzerland.
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13
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Rehling D, Scaletti ER, Rozman Grinberg I, Lundin D, Sahlin M, Hofer A, Sjöberg BM, Stenmark P. Structural and Biochemical Investigation of Class I Ribonucleotide Reductase from the Hyperthermophile Aquifex aeolicus. Biochemistry 2021; 61:92-106. [PMID: 34941255 PMCID: PMC8772380 DOI: 10.1021/acs.biochem.1c00503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ribonucleotide reductase (RNR) is an essential enzyme with a complex mechanism of allosteric regulation found in nearly all living organisms. Class I RNRs are composed of two proteins, a large α-subunit (R1) and a smaller β-subunit (R2) that exist as homodimers, that combine to form an active heterotetramer. Aquifex aeolicus is a hyperthermophilic bacterium with an unusual RNR encoding a 346-residue intein in the DNA sequence encoding its R2 subunit. We present the first structures of the A. aeolicus R1 and R2 (AaR1 and AaR2, respectively) proteins as well as the biophysical and biochemical characterization of active and inactive A. aeolicus RNR. While the active oligomeric state and activity regulation of A. aeolicus RNR are similar to those of other characterized RNRs, the X-ray crystal structures also reveal distinct features and adaptations. Specifically, AaR1 contains a β-hairpin hook structure at the dimer interface, which has an interesting π-stacking interaction absent in other members of the NrdAh subclass, and its ATP cone houses two ATP molecules. We determined structures of two AaR2 proteins: one purified from a construct lacking the intein (AaR2) and a second purified from a construct including the intein sequence (AaR2_genomic). These structures in the context of metal content analysis and activity data indicate that AaR2_genomic displays much higher iron occupancy and activity compared to AaR2, suggesting that the intein is important for facilitating complete iron incorporation, particularly in the Fe2 site of the mature R2 protein, which may be important for the survival of A. aeolicus in low-oxygen environments.
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Affiliation(s)
- Daniel Rehling
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Emma Rose Scaletti
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Inna Rozman Grinberg
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Anders Hofer
- Department of Biochemistry and Biophysics, Umeå University, SE-907 36 Umeå, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
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14
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Smethurst DGJ, Shcherbik N. Interchangeable utilization of metals: New perspectives on the impacts of metal ions employed in ancient and extant biomolecules. J Biol Chem 2021; 297:101374. [PMID: 34732319 PMCID: PMC8633580 DOI: 10.1016/j.jbc.2021.101374] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 02/08/2023] Open
Abstract
Metal ions provide considerable functionality across biological systems, and their utilization within biomolecules has adapted through changes in the chemical environment to maintain the activity they facilitate. While ancient earth's atmosphere was rich in iron and manganese and low in oxygen, periods of atmospheric oxygenation significantly altered the availability of certain metal ions, resulting in ion replacement within biomolecules. This adaptation mechanism has given rise to the phenomenon of metal cofactor interchangeability, whereby contemporary proteins and nucleic acids interact with multiple metal ions interchangeably, with different coordinated metals influencing biological activity, stability, and toxic potential. The ability of extant organisms to adapt to fluctuating metal availability remains relevant in a number of crucial biomolecules, including the superoxide dismutases of the antioxidant defense systems and ribonucleotide reductases. These well-studied and ancient enzymes illustrate the potential for metal interchangeability and adaptive utilization. More recently, the ribosome has also been demonstrated to exhibit interchangeable interactions with metal ions with impacts on function, stability, and stress adaptation. Using these and other examples, here we review the biological significance of interchangeable metal ions from a new angle that combines both biochemical and evolutionary viewpoints. The geochemical pressures and chemical properties that underlie biological metal utilization are discussed in the context of their impact on modern disease states and treatments.
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Affiliation(s)
- Daniel G J Smethurst
- Department for Cell Biology and Neuroscience, School of Osteopathic Medicine, Rowan University, Stratford, New Jersey, USA.
| | - Natalia Shcherbik
- Department for Cell Biology and Neuroscience, School of Osteopathic Medicine, Rowan University, Stratford, New Jersey, USA.
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15
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Abstract
Radicals in biology, once thought to all be bad actors, are now known to play a central role in many enzymatic reactions. Of the known radical-based enzymes, ribonucleotide reductases (RNRs) are pre-eminent as they are essential in the biology of all organisms by providing the building blocks and controlling the fidelity of DNA replication and repair. Intense examination of RNRs has led to the development of new tools and a guiding framework for the study of radicals in biology, pointing the way to future frontiers in radical enzymology.
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Affiliation(s)
- JoAnne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 20139 USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 20139 USA
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138 USA
| | - Daniel G. Nocera
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138 USA
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16
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Schell E, Nouairia G, Steiner E, Weber N, Lundin D, Loderer C. Structural determinants and distribution of phosphate specificity in ribonucleotide reductases. J Biol Chem 2021; 297:101008. [PMID: 34314684 PMCID: PMC8365446 DOI: 10.1016/j.jbc.2021.101008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 11/24/2022] Open
Abstract
Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to the corresponding deoxyribonucleotides, the building blocks of DNA. RNRs are specific for either ribonucleoside diphosphates or triphosphates as substrates. As far as is known, oxygen-dependent class I RNRs (NrdAB) all reduce ribonucleoside diphosphates, and oxygen-sensitive class III RNRs (NrdD) are all ribonucleoside triphosphate reducers, whereas the adenosylcobalamin-dependent class II (NrdJ) contains both ribonucleoside diphosphate and triphosphate reducers. However, it is unknown how this specificity is conveyed by the active site of the enzymes and how this feature developed in RNR evolution. By structural comparison of the active sites in different RNRs, we identified the apical loop of the phosphate-binding site as a potential structural determinant of substrate specificity. Grafting two residues from this loop from a diphosphate- to a triphosphate-specific RNR caused a change in preference from ribonucleoside triphosphate to diphosphate substrates in a class II model enzyme, confirming them as the structural determinants of phosphate specificity. The investigation of the phylogenetic distribution of this motif in class II RNRs yielded a likely monophyletic clade with the diphosphate-defining motif. This indicates a single evolutionary-split event early in NrdJ evolution in which diphosphate specificity developed from the earlier triphosphate specificity. For those interesting cases where organisms contain more than one nrdJ gene, we observed a preference for encoding enzymes with diverse phosphate specificities, suggesting that this varying phosphate specificity confers a selective advantage.
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Affiliation(s)
- Eugen Schell
- Institute for Microbiology, Technische Universität Dresden, Dresden, Saxony, Germany
| | - Ghada Nouairia
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Elisabeth Steiner
- Institute for Microbiology, Technische Universität Dresden, Dresden, Saxony, Germany
| | - Niclas Weber
- Institute for Microbiology, Technische Universität Dresden, Dresden, Saxony, Germany
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Christoph Loderer
- Institute for Microbiology, Technische Universität Dresden, Dresden, Saxony, Germany.
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17
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Hasan M, Banerjee I, Rozman Grinberg I, Sjöberg BM, Logan DT. Solution Structure of the dATP-Inactivated Class I Ribonucleotide Reductase From Leeuwenhoekiella blandensis by SAXS and Cryo-Electron Microscopy. Front Mol Biosci 2021; 8:713608. [PMID: 34381817 PMCID: PMC8350387 DOI: 10.3389/fmolb.2021.713608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 06/21/2021] [Indexed: 01/14/2023] Open
Abstract
The essential enzyme ribonucleotide reductase (RNR) is highly regulated both at the level of overall activity and substrate specificity. Studies of class I, aerobic RNRs have shown that overall activity is downregulated by the binding of dATP to a small domain known as the ATP-cone often found at the N-terminus of RNR subunits, causing oligomerization that prevents formation of a necessary α2β2 complex between the catalytic (α2) and radical generating (β2) subunits. In some relatively rare organisms with RNRs of the subclass NrdAi, the ATP-cone is found at the N-terminus of the β subunit rather than more commonly the α subunit. Binding of dATP to the ATP-cone in β results in formation of an unusual β4 tetramer. However, the structural basis for how the formation of the active complex is hindered by such oligomerization has not been studied. Here we analyse the low-resolution three-dimensional structures of the separate subunits of an RNR from subclass NrdAi, as well as the α4β4 octamer that forms in the presence of dATP. The results reveal a type of oligomer not previously seen for any class of RNR and suggest a mechanism for how binding of dATP to the ATP-cone switches off catalysis by sterically preventing formation of the asymmetrical α2β2 complex.
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Affiliation(s)
- Mahmudul Hasan
- Biochemistry and Structural Biology, Dept. of Chemistry, Lund University, Lund, Sweden
| | - Ipsita Banerjee
- Biochemistry and Structural Biology, Dept. of Chemistry, Lund University, Lund, Sweden
| | | | - Britt-Marie Sjöberg
- Dept. of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Derek T Logan
- Biochemistry and Structural Biology, Dept. of Chemistry, Lund University, Lund, Sweden
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18
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Frisch J, Maršić T, Loderer C. A Novel One-Pot Enzyme Cascade for the Biosynthesis of Cladribine Triphosphate. Biomolecules 2021; 11:biom11030346. [PMID: 33668847 PMCID: PMC7996316 DOI: 10.3390/biom11030346] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/19/2021] [Accepted: 02/22/2021] [Indexed: 02/06/2023] Open
Abstract
Cladribine triphosphate is the active compound of the anti-cancer and multiple sclerosis drug Mavenclad (cladribine). Biosynthesis of such non-natural deoxyribonucleotides is challenging but important in order to study the pharmaceutical modes of action. In this study, we developed a novel one-pot enzyme cascade for the biosynthesis of cladribine triphosphate, starting with the nucleobase 2Cl-adenine and the generic co-substrate phosphoribosyl pyrophosphate. The cascade is comprised of the three enzymes, namely, adenine phosphoribosyltransferase (APT), polyphosphate kinase (PPK), and ribonucleotide reductase (RNR). APT catalyzes the binding of the nucleobase to the ribose moiety, followed by two consecutive phosphorylation reactions by PPK. The formed nucleoside triphosphate is reduced to the final product 2Cl-deoxyadenonsine triphosphate (cladribine triphosphate) by the RNR. The cascade is feasible, showing comparative product concentrations and yields to existing enzyme cascades for nucleotide biosynthesis. While this study is limited to the biosynthesis of cladribine triphosphate, the design of the cascade offers the potential to extend its application to other important deoxyribonucleotides.
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Affiliation(s)
- Julia Frisch
- Chair for Molecular Biotechnology, Technical University, 01217 Dresden, Germany;
| | - Tin Maršić
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;
| | - Christoph Loderer
- Chair for Molecular Biotechnology, Technical University, 01217 Dresden, Germany;
- Correspondence: ; Tel.: +49-351-463-39517
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19
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Kirschning A. The coenzyme/protein pair and the molecular evolution of life. Nat Prod Rep 2020; 38:993-1010. [PMID: 33206101 DOI: 10.1039/d0np00037j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Covering: up to 2020What was first? Coenzymes or proteins? These questions are archetypal examples of causal circularity in living systems. Classically, this "chicken-and-egg" problem was discussed for the macromolecules RNA, DNA and proteins. This report focuses on coenzymes and cofactors and discusses the coenzyme/protein pair as another example of causal circularity in life. Reflections on the origin of life and hypotheses on possible prebiotic worlds led to the current notion that RNA was the first macromolecule, long before functional proteins and hence DNA. So these causal circularities of living systems were solved by a time travel into the past. To tackle the "chicken-and-egg" problem of the protein-coenzyme pair, this report addresses this problem by looking for clues (a) in the first hypothetical biotic life forms such as protoviroids and the last unified common ancestor (LUCA) and (b) in considerations and evidence of the possible prebiotic production of amino acids and coenzymes before life arose. According to these considerations, coenzymes and cofactors can be regarded as very old molecular players in the origin and evolution of life, and at least some of them developed independently of α-amino acids, which here are evolutionarily synonymous with proteins. Discussions on "chicken-and-egg" problems open further doors to the understanding of evolution.
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Affiliation(s)
- Andreas Kirschning
- Institut für Organische Chemie und Zentrum für Biomolekulare Wirkstoffchemie (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, D-30167 Hannover, Germany.
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20
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Martínez-Carranza M, Jonna VR, Lundin D, Sahlin M, Carlson LA, Jemal N, Högbom M, Sjöberg BM, Stenmark P, Hofer A. A ribonucleotide reductase from Clostridium botulinum reveals distinct evolutionary pathways to regulation via the overall activity site. J Biol Chem 2020; 295:15576-15587. [PMID: 32883811 DOI: 10.1074/jbc.ra120.014895] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/02/2020] [Indexed: 01/05/2023] Open
Abstract
Ribonucleotide reductase (RNR) is a central enzyme for the synthesis of DNA building blocks. Most aerobic organisms, including nearly all eukaryotes, have class I RNRs consisting of R1 and R2 subunits. The catalytic R1 subunit contains an overall activity site that can allosterically turn the enzyme on or off by the binding of ATP or dATP, respectively. The mechanism behind the ability to turn the enzyme off via the R1 subunit involves the formation of different types of R1 oligomers in most studied species and R1-R2 octamers in Escherichia coli To better understand the distribution of different oligomerization mechanisms, we characterized the enzyme from Clostridium botulinum, which belongs to a subclass of class I RNRs not studied before. The recombinantly expressed enzyme was analyzed by size-exclusion chromatography, gas-phase electrophoretic mobility macromolecular analysis, EM, X-ray crystallography, and enzyme assays. Interestingly, it shares the ability of the E. coli RNR to form inhibited R1-R2 octamers in the presence of dATP but, unlike the E. coli enzyme, cannot be turned off by combinations of ATP and dGTP/dTTP. A phylogenetic analysis of class I RNRs suggests that activity regulation is not ancestral but was gained after the first subclasses diverged and that RNR subclasses with inhibition mechanisms involving R1 oligomerization belong to a clade separated from the two subclasses forming R1-R2 octamers. These results give further insight into activity regulation in class I RNRs as an evolutionarily dynamic process.
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Affiliation(s)
| | | | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Lars-Anders Carlson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden; Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Newal Jemal
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden; Department of Experimental Medical Science, Lund University, Lund, Sweden.
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
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21
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Abstract
For evaluating the deepest evolutionary relationships among proteins, sequence similarity is too low for application of sequence-based homology search or phylogenetic methods. In such cases, comparison of protein structures, which are often better conserved than sequences, may provide an alternative means of uncovering deep evolutionary signal. Although major protein structure databases such as SCOP and CATH hierarchically group protein structures, they do not describe the specific evolutionary relationships within a hierarchical level. Structural phylogenies have the potential to fill this gap. However, it is difficult to assess evolutionary relationships derived from structural phylogenies without some means of assessing confidence in such trees. We therefore address two shortcomings in the application of structural data to deep phylogeny. First, we examine whether phylogenies derived from pairwise structural comparisons are sensitive to differences in protein length and shape. We find that structural phylogenetics is best employed where structures have very similar lengths, and that shape fluctuations generated during molecular dynamics simulations impact pairwise comparisons, but not so drastically as to eliminate evolutionary signal. Second, we address the absence of statistical support for structural phylogeny. We present a method for assessing confidence in a structural phylogeny using shape fluctuations generated via molecular dynamics or Monte Carlo simulations of proteins. Our approach will aid the evolutionary reconstruction of relationships across structurally defined protein superfamilies. With the Protein Data Bank now containing in excess of 158,000 entries (December 2019), we predict that structural phylogenetics will become a useful tool for ordering the protein universe.
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Affiliation(s)
- Ashar J Malik
- Centre for Theoretical Chemistry and Physics, School of Natural and Computational Sciences, Massey University Auckland, Auckland, New Zealand.,Bioinformatics Institute, Agency for Science, Technology and Research, Singapore
| | - Anthony M Poole
- Bioinformatics Institute, School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Digital Life Institute, University of Auckland, Auckland, New Zealand.,Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Jane R Allison
- Bioinformatics Institute, School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Digital Life Institute, University of Auckland, Auckland, New Zealand.,Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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22
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Minimal cobalt metabolism in the marine cyanobacterium Prochlorococcus. Proc Natl Acad Sci U S A 2020; 117:15740-15747. [PMID: 32576688 DOI: 10.1073/pnas.2001393117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite very low concentrations of cobalt in marine waters, cyanobacteria in the genus Prochlorococcus retain the genetic machinery for the synthesis and use of cobalt-bearing cofactors (cobalamins) in their genomes. We explore cobalt metabolism in a Prochlorococcus isolate from the equatorial Pacific Ocean (strain MIT9215) through a series of growth experiments under iron- and cobalt-limiting conditions. Metal uptake rates, quantitative proteomic measurements of cobalamin-dependent enzymes, and theoretical calculations all indicate that Prochlorococcus MIT9215 can sustain growth with less than 50 cobalt atoms per cell, ∼100-fold lower than minimum iron requirements for these cells (∼5,100 atoms per cell). Quantitative descriptions of Prochlorococcus cobalt limitation are used to interpret the cobalt distribution in the equatorial Pacific Ocean, where surface concentrations are among the lowest measured globally but Prochlorococcus biomass is high. A low minimum cobalt quota ensures that other nutrients, notably iron, will be exhausted before cobalt can be fully depleted, helping to explain the persistence of cobalt-dependent metabolism in marine cyanobacteria.
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23
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Ling B, Liao X, Huang Y, Liang L, Jiang Y, Pang Y, Qi G. Identification of prognostic markers of lung cancer through bioinformatics analysis and in vitro experiments. Int J Oncol 2020; 56:193-205. [PMID: 31789390 PMCID: PMC6910184 DOI: 10.3892/ijo.2019.4926] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/15/2019] [Indexed: 12/15/2022] Open
Abstract
Lung cancer is one of the most common types of cancer worldwide. Understanding the molecular mechanisms underlying the development and progression of lung cancer may improve early diagnosis, treatment and prognosis. The aim of the present study was to examine the pathogenesis of lung cancer and to identify potentially novel biomarkers. Gene expression datasets of patients with lung cancer were obtained from the Gene Expression Omnibus. Genes which were most closely associated with lung cancer (core genes) were screened by weighted gene co‑expression network analysis. In vitro cell based experiments were further utilized to verify the effects of the core genes on the proliferation of lung cancer cells, adhesion between cells and the matrix, and the associated metabolic pathways. Based on WGCNA screening, two gene modules and five core genes closely associated with lung cancer, including immunoglobulin superfamily member 10 (IGSF10) from the turquoise module, and ribonucleotide reductase regulatory subunit M2, protein regulator of cytokinesis 1, kinesin family member (KIF)14 and KIF2C from the brown module were identified as relevant. Survival analysis and differential gene expression analysis showed that there were significant differences in IGSF10 expression levels between the healthy controls and patients with lung cancer. In patients with lung cancer, IGSF10 expression was decreased, and the overall survival time of patients with lung cancer was significantly shortened. An MTT and colony formation assay showed that IGSF10‑knockout significantly increased proliferation of lung cancer cells, and Transwell assays and adhesion experiments further suggested that the adhesion between cells and the matrix was significantly increased in IGSF10‑knockout cells. Gene Set Enrichment Analysis showed that the expression level of IGSF10 was significantly associated with the activation of the integrin‑β1/focal adhesion kinase (FAK) pathway. Western blotting revealed that knockout of IGSF10 resulted in the activation of the integrin‑β1/FAK pathway, as the protein expression levels of integrin‑β1, phosphorylated (p)‑FAK and p‑AKT were significantly upregulated. Activation of the integrin‑β1/FAK pathway, following knockout of IGSF10, affected the proliferation and adhesion of lung cancer cells. Therefore, IGSF10 my serve as a potential prognostic marker of lung cancer.
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Affiliation(s)
| | | | - Yuanhe Huang
- Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, Guangxi 533000
| | | | - Yan Jiang
- Medical College, Guangxi University, Nanning, Guangxi 530004
| | - Yaqin Pang
- College of Public Health and Management, Youjiang Medical University for Nationalities, Baise, Guangxi 533000, P.R. China
| | - Guangzi Qi
- College of Public Health and Management, Youjiang Medical University for Nationalities, Baise, Guangxi 533000, P.R. China
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24
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Mebs S, Srinivas V, Kositzki R, Griese JJ, Högbom M, Haumann M. Fate of oxygen species from O 2 activation at dimetal cofactors in an oxidase enzyme revealed by 57Fe nuclear resonance X-ray scattering and quantum chemistry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148060. [PMID: 31394094 DOI: 10.1016/j.bbabio.2019.148060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/30/2019] [Accepted: 08/02/2019] [Indexed: 10/26/2022]
Abstract
Oxygen (O2) activation is a central challenge in chemistry and catalyzed at prototypic dimetal cofactors in biological enzymes with diverse functions. Analysis of intermediates is required to elucidate the reaction paths of reductive O2 cleavage. An oxidase protein from the bacterium Geobacillus kaustophilus, R2lox, was used for aerobic in-vitro reconstitution with only 57Fe(II) or Mn(II) plus 57Fe(II) ions to yield [FeFe] or [MnFe] cofactors under various oxygen and solvent isotopic conditions including 16/18O and H/D exchange. 57Fe-specific X-ray scattering techniques were employed to collect nuclear forward scattering (NFS) and nuclear resonance vibrational spectroscopy (NRVS) data of the R2lox proteins. NFS revealed Fe/Mn(III)Fe(III) cofactor states and Mössbauer quadrupole splitting energies. Quantum chemical calculations of NRVS spectra assigned molecular structures, vibrational modes, and protonation patterns of the cofactors, featuring a terminal water (H2O) bound at iron or manganese in site 1 and a metal-bridging hydroxide (μOH-) ligand. A procedure for quantitation and correlation of experimental and computational NRVS difference signals due to isotope labeling was developed. This approach revealed that the protons of the ligands as well as the terminal water at the R2lox cofactors exchange with the bulk solvent whereas 18O from 18O2 cleavage is incorporated in the hydroxide bridge. In R2lox, the two water molecules from four-electron O2 reduction are released in a two-step reaction to the solvent. These results establish combined NRVS and QM/MM for tracking of iron-based oxygen activation in biological and chemical catalysts and clarify the reductive O2 cleavage route in an enzyme.
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Affiliation(s)
- Stefan Mebs
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Vivek Srinivas
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16, 10691 Stockholm, Sweden
| | - Ramona Kositzki
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Julia J Griese
- Department of Cell and Molecular Biology, Structural Biology, Uppsala University, Box 596, 75124 Uppsala, Sweden
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16, 10691 Stockholm, Sweden
| | - Michael Haumann
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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25
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Class Id ribonucleotide reductase utilizes a Mn 2(IV,III) cofactor and undergoes large conformational changes on metal loading. J Biol Inorg Chem 2019; 24:863-877. [PMID: 31414238 PMCID: PMC6754362 DOI: 10.1007/s00775-019-01697-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 08/02/2019] [Indexed: 12/15/2022]
Abstract
Outside of the photosynthetic machinery, high-valent manganese cofactors are rare in biology. It was proposed that a recently discovered subclass of ribonucleotide reductase (RNR), class Id, is dependent on a Mn2(IV,III) cofactor for catalysis. Class I RNRs consist of a substrate-binding component (NrdA) and a metal-containing radical-generating component (NrdB). Herein we utilize a combination of EPR spectroscopy and enzyme assays to underscore the enzymatic relevance of the Mn2(IV,III) cofactor in class Id NrdB from Facklamia ignava. Once formed, the Mn2(IV,III) cofactor confers enzyme activity that correlates well with cofactor quantity. Moreover, we present the X-ray structure of the apo- and aerobically Mn-loaded forms of the homologous class Id NrdB from Leeuwenhoekiella blandensis, revealing a dimanganese centre typical of the subclass, with a tyrosine residue maintained at distance from the metal centre and a lysine residue projected towards the metals. Structural comparison of the apo- and metal-loaded forms of the protein reveals a refolding of the loop containing the conserved lysine and an unusual shift in the orientation of helices within a monomer, leading to the opening of a channel towards the metal site. Such major conformational changes have not been observed in NrdB proteins before. Finally, in vitro reconstitution experiments reveal that the high-valent manganese cofactor is not formed spontaneously from oxygen, but can be generated from at least two different reduced oxygen species, i.e. H2O2 and superoxide (O 2 ·- ). Considering the observed differences in the efficiency of these two activating reagents, we propose that the physiologically relevant mechanism involves superoxide.
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26
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Berggren G, Sahlin M, Crona M, Tholander F, Sjöberg BM. Compounds with capacity to quench the tyrosyl radical in Pseudomonas aeruginosa ribonucleotide reductase. J Biol Inorg Chem 2019; 24:841-848. [PMID: 31218442 PMCID: PMC6754346 DOI: 10.1007/s00775-019-01679-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/12/2019] [Indexed: 11/02/2022]
Abstract
Ribonucleotide reductase (RNR) has been extensively probed as a target enzyme in the search for selective antibiotics. Here we report on the mechanism of inhibition of nine compounds, serving as representative examples of three different inhibitor classes previously identified by us to efficiently inhibit RNR. The interaction between the inhibitors and Pseudomonas aeruginosa RNR was elucidated using a combination of electron paramagnetic resonance spectroscopy and thermal shift analysis. All nine inhibitors were found to efficiently quench the tyrosyl radical present in RNR, required for catalysis. Three different mechanisms of radical quenching were identified, and shown to depend on reduction potential of the assay solution and quaternary structure of the protein complex. These results form a good foundation for further development of P. aeruginosa selective antibiotics. Moreover, this study underscores the complex nature of RNR inhibition and the need for detailed spectroscopic studies to unravel the mechanism of RNR inhibitors.
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Affiliation(s)
- Gustav Berggren
- Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala, Sweden.
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Mikael Crona
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Swedish Orphan Biovitrum AB, Stockholm, Sweden
| | - Fredrik Tholander
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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27
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Thomas WC, Brooks FP, Burnim AA, Bacik JP, Stubbe J, Kaelber JT, Chen JZ, Ando N. Convergent allostery in ribonucleotide reductase. Nat Commun 2019; 10:2653. [PMID: 31201319 PMCID: PMC6572854 DOI: 10.1038/s41467-019-10568-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 05/20/2019] [Indexed: 02/04/2023] Open
Abstract
Ribonucleotide reductases (RNRs) use a conserved radical-based mechanism to catalyze the conversion of ribonucleotides to deoxyribonucleotides. Within the RNR family, class Ib RNRs are notable for being largely restricted to bacteria, including many pathogens, and for lacking an evolutionarily mobile ATP-cone domain that allosterically controls overall activity. In this study, we report the emergence of a distinct and unexpected mechanism of activity regulation in the sole RNR of the model organism Bacillus subtilis. Using a hypothesis-driven structural approach that combines the strengths of small-angle X-ray scattering (SAXS), crystallography, and cryo-electron microscopy (cryo-EM), we describe the reversible interconversion of six unique structures, including a flexible active tetramer and two inhibited helical filaments. These structures reveal the conformational gymnastics necessary for RNR activity and the molecular basis for its control via an evolutionarily convergent form of allostery. Ribonucleotide reductase (RNR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides, which is an essential step in DNA synthesis. Here the authors use small-angle X-ray scattering, X-ray crystallography, and cryo-electron microscopy to capture active and inactive forms of the Bacillus subtilis RNR and provide mechanistic insights into a convergent form of allosteric regulation.
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Affiliation(s)
- William C Thomas
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA.,Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - F Phil Brooks
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Audrey A Burnim
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA.,Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - John-Paul Bacik
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA.,Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - JoAnne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jason T Kaelber
- Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ, 08854, USA
| | - James Z Chen
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Nozomi Ando
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA. .,Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA.
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28
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Rose HR, Maggiolo AO, McBride MJ, Palowitch GM, Pandelia ME, Davis KM, Yennawar NH, Boal AK. Structures of Class Id Ribonucleotide Reductase Catalytic Subunits Reveal a Minimal Architecture for Deoxynucleotide Biosynthesis. Biochemistry 2019; 58:1845-1860. [PMID: 30855138 PMCID: PMC6456427 DOI: 10.1021/acs.biochem.8b01252] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Class I ribonucleotide reductases (RNRs) share a common mechanism of nucleotide reduction in a catalytic α subunit. All RNRs initiate catalysis with a thiyl radical, generated in class I enzymes by a metallocofactor in a separate β subunit. Class Id RNRs use a simple mechanism of cofactor activation involving oxidation of a MnII2 cluster by free superoxide to yield a metal-based MnIIIMnIV oxidant. This simple cofactor assembly pathway suggests that class Id RNRs may be representative of the evolutionary precursors to more complex class Ia-c enzymes. X-ray crystal structures of two class Id α proteins from Flavobacterium johnsoniae ( Fj) and Actinobacillus ureae ( Au) reveal that this subunit is distinctly small. The enzyme completely lacks common N-terminal ATP-cone allosteric motifs that regulate overall activity, a process that normally occurs by dATP-induced formation of inhibitory quaternary structures to prevent productive β subunit association. Class Id RNR activity is insensitive to dATP in the Fj and Au enzymes evaluated here, as expected. However, the class Id α protein from Fj adopts higher-order structures, detected crystallographically and in solution. The Au enzyme does not exhibit these quaternary forms. Our study reveals structural similarity between bacterial class Id and eukaryotic class Ia α subunits in conservation of an internal auxiliary domain. Our findings with the Fj enzyme illustrate that nucleotide-independent higher-order quaternary structures can form in simple RNRs with truncated or missing allosteric motifs.
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Affiliation(s)
- Hannah R. Rose
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Ailiena O. Maggiolo
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Molly J. McBride
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Gavin M. Palowitch
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | | | - Katherine M. Davis
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Neela H. Yennawar
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Amie K. Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
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29
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Loderer C, Holmfeldt K, Lundin D. Non-host class II ribonucleotide reductase in Thermus viruses: sequence adaptation and host interaction. PeerJ 2019; 7:e6700. [PMID: 30993041 PMCID: PMC6459318 DOI: 10.7717/peerj.6700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/01/2019] [Indexed: 01/14/2023] Open
Abstract
Ribonucleotide reductases (RNR) are essential enzymes for all known life forms. Their current taxonomic distribution suggests extensive horizontal gene transfer e.g., by processes involving viruses. To improve our understanding of the underlying processes, we characterized a monomeric class II RNR (NrdJm) enzyme from a Thermus virus, a subclass not present in any sequenced Thermus spp. genome. Phylogenetic analysis revealed a distant origin of the nrdJm gene with the most closely related sequences found in mesophiles or moderate thermophiles from the Firmicutes phylum. GC-content, codon usage and the ratio of coding to non-coding substitutions (dN/dS) suggest extensive adaptation of the gene in the virus in terms of nucleotide composition and amino acid sequence. The NrdJm enzyme is a monomeric B12-dependent RNR with nucleoside triphosphate specificity. It exhibits a temperature optimum at 60–70 °C, which is in the range of the growth optimum of Thermus spp. Experiments in combination with the Thermus thermophilus thioredoxin system show that the enzyme is able to retrieve electrons from the host NADPH pool via host thioredoxin and thioredoxin reductases. This is different from other characterized viral RNRs such as T4 phage RNR, where a viral thioredoxin is present. We hence show that the monomeric class II RNR, present in Thermus viruses, was likely transferred from an organism phylogenetically distant from the one they were isolated from, and adapted to the new host in genetic signature and amino acids sequence.
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Affiliation(s)
- Christoph Loderer
- Institute for Microbiology, Technische Universität Dresden, Dresden, Saxony, Germany
| | - Karin Holmfeldt
- Centre for Ecology and Evolution in Microbial model Systems-EEMiS, Linnaeus University, Kalmar, Sweden
| | - Daniel Lundin
- Centre for Ecology and Evolution in Microbial model Systems-EEMiS, Linnaeus University, Kalmar, Sweden.,Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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30
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Harrison AO, Moore RM, Polson SW, Wommack KE. Reannotation of the Ribonucleotide Reductase in a Cyanophage Reveals Life History Strategies Within the Virioplankton. Front Microbiol 2019; 10:134. [PMID: 30804913 PMCID: PMC6370689 DOI: 10.3389/fmicb.2019.00134] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/21/2019] [Indexed: 01/16/2023] Open
Abstract
Ribonucleotide reductases (RNRs) are ancient enzymes that catalyze the reduction of ribonucleotides to deoxyribonucleotides. They are required for virtually all cellular life and are prominent within viral genomes. RNRs share a common ancestor and must generate a protein radical for direct ribonucleotide reduction. The mechanisms by which RNRs produce radicals are diverse and divide RNRs into three major classes and several subclasses. The diversity of radical generation methods means that cellular organisms and viruses typically contain the RNR best-suited to the environmental conditions surrounding DNA replication. However, such diversity has also fostered high rates of RNR misannotation within subject sequence databases. These misannotations have resulted in incorrect translative presumptions of RNR biochemistry and have diminished the utility of this marker gene for ecological studies of viruses. We discovered a misannotation of the RNR gene within the Prochlorococcus phage P-SSP7 genome, which caused a chain of misannotations within commonly observed RNR genes from marine virioplankton communities. These RNRs are found in marine cyanopodo- and cyanosiphoviruses and are currently misannotated as Class II RNRs, which are O2-independent and require cofactor B12. In fact, these cyanoviral RNRs are Class I enzymes that are O2-dependent and may require a di-metal cofactor made of Fe, Mn, or a combination of the two metals. The discovery of an overlooked Class I β subunit in the P-SSP7 genome, together with phylogenetic analysis of the α and β subunits confirms that the RNR from P-SSP7 is a Class I RNR. Phylogenetic and conserved residue analyses also suggest that the P-SSP7 RNR may constitute a novel Class I subclass. The reannotation of the RNR clade represented by P-SSP7 means that most lytic cyanophage contain Class I RNRs, while their hosts, B12-producing Synechococcus and Prochlorococcus, contain Class II RNRs. By using a Class I RNR, cyanophage avoid a dependence on host-produced B12, a more effective strategy for a lytic virus. The discovery of a novel RNR β subunit within cyanopodoviruses also implies that some unknown viral genes may be familiar cellular genes that are too divergent for homology-based annotation methods to identify.
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Affiliation(s)
- Amelia O. Harrison
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States
| | - Ryan M. Moore
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States
| | - Shawn W. Polson
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States
| | - K. Eric Wommack
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States
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31
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Miret-Casals L, Baelo A, Julián E, Astola J, Lobo-Ruiz A, Albericio F, Torrents E. Hydroxylamine Derivatives as a New Paradigm in the Search of Antibacterial Agents. ACS OMEGA 2018; 3:17057-17069. [PMID: 31458325 PMCID: PMC6643834 DOI: 10.1021/acsomega.8b01384] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/28/2018] [Indexed: 06/10/2023]
Abstract
Serious infections caused by bacteria that are resistant to commonly used antibiotics have become a major global healthcare problem in the 21st century. Multidrug-resistant bacteria causing severe infections mainly grow in complex bacterial communities known as biofilms, in which bacterial resistance to antibacterial agents and to the host immune system is strengthened. As drug resistance is becoming a threatening problem, it is necessary to develop new antimicrobial agents with novel mechanisms of action. Here, we designed and synthesized a small library of N-substituted hydroxylamine (N-HA) compounds with antibacterial activity. These compounds, acting as radical scavengers, inhibit the bacterial ribonucleotide reductase (RNR) enzyme. RNR enzyme is essential for bacterial proliferation during infection, as it provides the building blocks for DNA synthesis and repair. We demonstrate the broad antimicrobial effect of several drug candidates against a variety of Gram-positive and Gram-negative bacteria, together with low toxicity toward eukaryotic cells. Furthermore, the most promising compounds can reduce the biomass of an established biofilm on Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. This study settles the starting point to develop new N-hydroxylamine compounds as potential effective antibacterial agents to fight against drug-resistant pathogenic bacteria.
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Affiliation(s)
- Laia Miret-Casals
- Department
of Organic Chemistry, University of Barcelona, C/ Martí i Franquès,
1-11, 08028 Barcelona, Spain
| | - Aida Baelo
- Bacterial
Infections: Antimicrobial Therapies, Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac, 15-21, 08028 Barcelona, Spain
| | - Esther Julián
- Group
of Mycobacteriology, Department of Genetics
and Microbiology, Facultat de Biociències Universitat Autònoma de Barcelona, Building C, 08193 Bellaterra, Barcelona, Spain
| | - Josep Astola
- Bacterial
Infections: Antimicrobial Therapies, Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac, 15-21, 08028 Barcelona, Spain
| | - Ariadna Lobo-Ruiz
- Department
of Organic Chemistry, University of Barcelona, C/ Martí i Franquès,
1-11, 08028 Barcelona, Spain
| | - Fernando Albericio
- Department
of Organic Chemistry, University of Barcelona, C/ Martí i Franquès,
1-11, 08028 Barcelona, Spain
- CIBER-BBN,
Networking Centre on Bioengineering, Biomaterials and Nanomedicine, C/ Martí i Franquès,
1-11, 08028 Barcelona, Spain
- School
of Chemistry & Physics, University of
Kwazulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
| | - Eduard Torrents
- Bacterial
Infections: Antimicrobial Therapies, Institute
for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac, 15-21, 08028 Barcelona, Spain
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32
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Rozman Grinberg I, Lundin D, Sahlin M, Crona M, Berggren G, Hofer A, Sjöberg BM. A glutaredoxin domain fused to the radical-generating subunit of ribonucleotide reductase (RNR) functions as an efficient RNR reductant. J Biol Chem 2018; 293:15889-15900. [PMID: 30166338 PMCID: PMC6187632 DOI: 10.1074/jbc.ra118.004991] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/27/2018] [Indexed: 01/08/2023] Open
Abstract
Class I ribonucleotide reductase (RNR) consists of a catalytic subunit (NrdA) and a radical-generating subunit (NrdB) that together catalyze reduction of ribonucleotides to their corresponding deoxyribonucleotides. NrdB from the firmicute Facklamia ignava is a unique fusion protein with N-terminal add-ons of a glutaredoxin (Grx) domain followed by an ATP-binding domain, the ATP cone. Grx, usually encoded separately from the RNR operon, is a known RNR reductant. We show that the fused Grx domain functions as an efficient reductant of the F. ignava class I RNR via the common dithiol mechanism and, interestingly, also via a monothiol mechanism, although less efficiently. To our knowledge, a Grx that uses both of these two reaction mechanisms has not previously been observed with a native substrate. The ATP cone is in most RNRs an N-terminal domain of the catalytic subunit. It is an allosteric on/off switch promoting ribonucleotide reduction in the presence of ATP and inhibiting RNR activity in the presence of dATP. We found that dATP bound to the ATP cone of F. ignava NrdB promotes formation of tetramers that cannot form active complexes with NrdA. The ATP cone bound two dATP molecules but only one ATP molecule. F. ignava NrdB contains the recently identified radical-generating cofactor MnIII/MnIV We show that NrdA from F. ignava can form a catalytically competent RNR with the MnIII/MnIV-containing NrdB from the flavobacterium Leeuwenhoekiella blandensis In conclusion, F. ignava NrdB is fused with a Grx functioning as an RNR reductant and an ATP cone serving as an on/off switch.
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Affiliation(s)
- Inna Rozman Grinberg
- From the Department of Biochemistry and Biophysics, Stockholm University SE-10691 Stockholm, Sweden
| | - Daniel Lundin
- From the Department of Biochemistry and Biophysics, Stockholm University SE-10691 Stockholm, Sweden
| | - Margareta Sahlin
- From the Department of Biochemistry and Biophysics, Stockholm University SE-10691 Stockholm, Sweden
| | - Mikael Crona
- From the Department of Biochemistry and Biophysics, Stockholm University SE-10691 Stockholm, Sweden
- the Swedish Orphan Biovitrum AB, SE-112 76 Stockholm, Sweden
| | - Gustav Berggren
- the Department of Chemistry, Uppsala University, SE-752 36 Uppsala, Sweden, and
| | - Anders Hofer
- the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | - Britt-Marie Sjöberg
- From the Department of Biochemistry and Biophysics, Stockholm University SE-10691 Stockholm, Sweden,
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33
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Myllykallio H, Sournia P, Heliou A, Liebl U. Unique Features and Anti-microbial Targeting of Folate- and Flavin-Dependent Methyltransferases Required for Accurate Maintenance of Genetic Information. Front Microbiol 2018; 9:918. [PMID: 29867829 PMCID: PMC5954106 DOI: 10.3389/fmicb.2018.00918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022] Open
Abstract
Comparative genome analyses have led to the discovery and characterization of novel flavin- and folate-dependent methyltransferases that mainly function in DNA precursor synthesis and post-transcriptional RNA modification by forming (ribo) thymidylate and its derivatives. Here we discuss the recent literature on the novel mechanistic features of these enzymes sometimes referred to as “uracil methyltransferases,” albeit we prefer to refer to them as (ribo) thymidylate synthases. These enzyme families attest to the convergent evolution of nucleic acid methylation. Special focus is given to describing the unique characteristics of these flavin- and folate-dependent enzymes that have emerged as new models for studying the non-canonical roles of reduced flavin co-factors (FADH2) in relaying carbon atoms between enzyme substrates. This ancient enzymatic methylation mechanism with a very wide phylogenetic distribution may be more commonly used for biological methylation reactions than previously anticipated. This notion is exemplified by the recent discovery of additional substrates for these enzymes. Moreover, similar reaction mechanisms can be reversed by demethylases, which remove methyl groups e.g., from human histones. Future work is now required to address whether the use of different methyl donors facilitates the regulation of distinct methylation reactions in the cell. It will also be of great interest to address whether the low activity flavin-dependent thymidylate synthases ThyX represent ancestral enzymes that were eventually replaced by the more active thymidylate synthases of the ThyA family to facilitate the maintenance of larger genomes in fast-growing microbes. Moreover, we discuss the recent efforts from several laboratories to identify selective anti-microbial compounds that target flavin-dependent thymidylate synthase ThyX. Altogether we underline how the discovery of the alternative flavoproteins required for methylation of DNA and/or RNA nucleotides, in addition to providing novel targets for antibiotics, has provided new insight into microbial physiology and virulence.
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Affiliation(s)
- Hannu Myllykallio
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
| | - Pierre Sournia
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
| | - Alice Heliou
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France.,Laboratoire d'Informatique de l'École Polytechnique, Ecole Polytechnique, Centre National de la Recherche Scientifique, Université Paris-Saclay, Palaiseau, France
| | - Ursula Liebl
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Palaiseau, France
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34
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Rose HR, Ghosh MK, Maggiolo AO, Pollock CJ, Blaesi EJ, Hajj V, Wei Y, Rajakovich LJ, Chang WC, Han Y, Hajj M, Krebs C, Silakov A, Pandelia ME, Bollinger JM, Boal AK. Structural Basis for Superoxide Activation of Flavobacterium johnsoniae Class I Ribonucleotide Reductase and for Radical Initiation by Its Dimanganese Cofactor. Biochemistry 2018; 57:2679-2693. [PMID: 29609464 DOI: 10.1021/acs.biochem.8b00247] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A ribonucleotide reductase (RNR) from Flavobacterium johnsoniae ( Fj) differs fundamentally from known (subclass a-c) class I RNRs, warranting its assignment to a new subclass, Id. Its β subunit shares with Ib counterparts the requirements for manganese(II) and superoxide (O2-) for activation, but it does not require the O2--supplying flavoprotein (NrdI) needed in Ib systems, instead scavenging the oxidant from solution. Although Fj β has tyrosine at the appropriate sequence position (Tyr 104), this residue is not oxidized to a radical upon activation, as occurs in the Ia/b proteins. Rather, Fj β directly deploys an oxidized dimanganese cofactor for radical initiation. In treatment with one-electron reductants, the cofactor can undergo cooperative three-electron reduction to the II/II state, in contrast to the quantitative univalent reduction to inactive "met" (III/III) forms seen with I(a-c) βs. This tendency makes Fj β unusually robust, as the II/II form can readily be reactivated. The structure of the protein rationalizes its distinctive traits. A distortion in a core helix of the ferritin-like architecture renders the active site unusually open, introduces a cavity near the cofactor, and positions a subclass-d-specific Lys residue to shepherd O2- to the Mn2II/II cluster. Relative to the positions of the radical tyrosines in the Ia/b proteins, the unreactive Tyr 104 of Fj β is held away from the cofactor by a hydrogen bond with a subclass-d-specific Thr residue. Structural comparisons, considered with its uniquely simple mode of activation, suggest that the Id protein might most closely resemble the primordial RNR-β.
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Affiliation(s)
| | | | | | | | | | | | - Yifeng Wei
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | | | | | | | | | | | | | - Maria-Eirini Pandelia
- Department of Biochemistry , Brandeis University , Waltham , Massachusetts 02454 , United States
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35
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Rozman Grinberg I, Lundin D, Hasan M, Crona M, Jonna VR, Loderer C, Sahlin M, Markova N, Borovok I, Berggren G, Hofer A, Logan DT, Sjöberg BM. Novel ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit. eLife 2018; 7:31529. [PMID: 29388911 PMCID: PMC5794259 DOI: 10.7554/elife.31529] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/23/2017] [Indexed: 12/27/2022] Open
Abstract
Ribonucleotide reductases (RNRs) are key enzymes in DNA metabolism, with allosteric mechanisms controlling substrate specificity and overall activity. In RNRs, the activity master-switch, the ATP-cone, has been found exclusively in the catalytic subunit. In two class I RNR subclasses whose catalytic subunit lacks the ATP-cone, we discovered ATP-cones in the radical-generating subunit. The ATP-cone in the Leeuwenhoekiella blandensis radical-generating subunit regulates activity via quaternary structure induced by binding of nucleotides. ATP induces enzymatically competent dimers, whereas dATP induces non-productive tetramers, resulting in different holoenzymes. The tetramer forms by interactions between ATP-cones, shown by a 2.45 Å crystal structure. We also present evidence for an MnIIIMnIV metal center. In summary, lack of an ATP-cone domain in the catalytic subunit was compensated by transfer of the domain to the radical-generating subunit. To our knowledge, this represents the first observation of transfer of an allosteric domain between components of the same enzyme complex. When a cell copies its DNA, it uses four different building blocks called deoxyribonucleotides (dNTPs). These consist of one of the four ‘bases’ (A, T, C and G), which pair up to link the two strands of DNA in the double helix, bound to a sugar and a phosphate group. If the cell contains too little or too much of one of these building blocks, an incorrect base may be inserted into the DNA. This results in a mutation, which in bacteria can cause death, and in animals may lead to cancer. The enzyme that fabricates and carefully controls the amount of each dNTP building block inside a cell is called ribonucleotide reductase. Once there are enough building blocks in a cell the enzyme is turned off. A part of the enzyme called the ATP-cone acts as an on/off switch to control this activity. The ribonucleotide reductase consists of a large component and a small component. Until now, studies of the ATP-cone have found it only in the large component of the enzyme. However, when looking through a public database of sequence data, Rozman Grinberg et al. noticed that ribonucleotide reductases in some bacteria have their ATP-cone joined to the small component. Does this ATP-cone also control the amounts of dNTP building blocks inside cells and, if so, how? Rozman Grinberg et al. studied one such ATP-cone in a ribonucleotide reductase from a bacterium (named Leeuwenhoekiella blandensis) found in the Mediterranean Sea. This revealed that when the amount of dNTP building blocks reaches a certain limit, the ATP-cone turns off the enzyme. Examining the three-dimensional structure of the enzyme using a technique called X-ray crystallography revealed that when turned off, the enzyme’s small components are glued together in pairs. This prevents them from working. Rozman Grinberg et al. also discovered that this enzyme contains a new type of metal center with two manganese ions suggesting that a new reaction mechanism may operate in this class of ribonucleotide reductase. These findings support a theory that biological on/off switches can evolve rapidly. In addition to its evolutionary and biomedical interest, understanding how the ATP-cone works might help to improve the enzymes used in industrial processes.
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Affiliation(s)
- Inna Rozman Grinberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Mahmudul Hasan
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | | | | | - Christoph Loderer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | | | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Gustav Berggren
- Department of Chemistry, Uppsala University, Uppsala, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Derek T Logan
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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Loderer C, Jonna VR, Crona M, Rozman Grinberg I, Sahlin M, Hofer A, Lundin D, Sjöberg BM. A unique cysteine-rich zinc finger domain present in a majority of class II ribonucleotide reductases mediates catalytic turnover. J Biol Chem 2017; 292:19044-19054. [PMID: 28972190 PMCID: PMC5704485 DOI: 10.1074/jbc.m117.806331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/28/2017] [Indexed: 12/04/2022] Open
Abstract
Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to the corresponding deoxyribonucleotides, used in DNA synthesis and repair. Two different mechanisms help deliver the required electrons to the RNR active site. Formate can be used as reductant directly in the active site, or glutaredoxins or thioredoxins reduce a C-terminal cysteine pair, which then delivers the electrons to the active site. Here, we characterized a novel cysteine-rich C-terminal domain (CRD), which is present in most class II RNRs found in microbes. The NrdJd-type RNR from the bacterium Stackebrandtia nassauensis was used as a model enzyme. We show that the CRD is involved in both higher oligomeric state formation and electron transfer to the active site. The CRD-dependent formation of high oligomers, such as tetramers and hexamers, was induced by addition of dATP or dGTP, but not of dTTP or dCTP. The electron transfer was mediated by an array of six cysteine residues at the very C-terminal end, which also coordinated a zinc atom. The electron transfer can also occur between subunits, depending on the enzyme's oligomeric state. An investigation of the native reductant of the system revealed no interaction with glutaredoxins or thioredoxins, indicating that this class II RNR uses a different electron source. Our results indicate that the CRD has a crucial role in catalytic turnover and a potentially new terminal reduction mechanism and suggest that the CRD is important for the activities of many class II RNRs.
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Affiliation(s)
- Christoph Loderer
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
| | | | - Mikael Crona
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
| | - Inna Rozman Grinberg
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
| | - Margareta Sahlin
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
| | - Anders Hofer
- the Department of Medical Biochemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Daniel Lundin
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
| | - Britt-Marie Sjöberg
- From the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden and
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Backman LRF, Funk MA, Dawson CD, Drennan CL. New tricks for the glycyl radical enzyme family. Crit Rev Biochem Mol Biol 2017; 52:674-695. [PMID: 28901199 DOI: 10.1080/10409238.2017.1373741] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glycyl radical enzymes (GREs) are important biological catalysts in both strict and facultative anaerobes, playing key roles both in the human microbiota and in the environment. GREs contain a backbone glycyl radical that is post-translationally installed, enabling radical-based mechanisms. GREs function in several metabolic pathways including mixed acid fermentation, ribonucleotide reduction and the anaerobic breakdown of the nutrient choline and the pollutant toluene. By generating a substrate-based radical species within the active site, GREs enable C-C, C-O and C-N bond breaking and formation steps that are otherwise challenging for nonradical enzymes. Identification of previously unknown family members from genomic data and the determination of structures of well-characterized GREs have expanded the scope of GRE-catalyzed reactions as well as defined key features that enable radical catalysis. Here, we review the structures and mechanisms of characterized GREs, classifying members into five categories. We consider the open questions about each of the five GRE classes and evaluate the tools available to interrogate uncharacterized GREs.
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Affiliation(s)
- Lindsey R F Backman
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Michael A Funk
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA.,b Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , IL , USA
| | - Christopher D Dawson
- c Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Catherine L Drennan
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA.,c Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA.,d Howard Hughes Medical Institute , Massachusetts Institute of Technology , Cambridge , MA , USA
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Knappenberger AJ, Grandhi S, Sheth R, Ahmad MF, Viswanathan R, Harris ME. Phylogenetic sequence analysis and functional studies reveal compensatory amino acid substitutions in loop 2 of human ribonucleotide reductase. J Biol Chem 2017; 292:16463-16476. [PMID: 28808063 DOI: 10.1074/jbc.m117.798769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/17/2017] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic class I ribonucleotide reductases (RRs) generate deoxyribonucleotides for DNA synthesis. Binding of dNTP effectors is coupled to the formation of active dimers and induces conformational changes in a short loop (loop 2) to regulate RR specificity among its nucleoside diphosphate substrates. Moreover, ATP and dATP bind at an additional allosteric site 40 Å away from loop 2 and thereby drive formation of activated or inactive hexamers, respectively. To better understand how dNTP binding influences specificity, activity, and oligomerization of human RR, we aligned >300 eukaryotic RR sequences to examine natural sequence variation in loop 2. We found that most amino acids in eukaryotic loop 2 were nearly invariant in this sample; however, two positions co-varied as nonconservative substitutions (N291G and P294K; human numbering). We also found that the individual N291G and P294K substitutions in human RR additively affect substrate specificity. The P294K substitution significantly impaired effector-induced oligomerization required for enzyme activity, and oligomerization was rescued in the N291G/P294K enzyme. None of the other mutants exhibited altered ATP-mediated hexamerization; however, certain combinations of loop 2 mutations and dNTP effectors perturbed ATP's role as an allosteric activator. Our results demonstrate that the observed compensatory covariation of amino acids in eukaryotic loop 2 is essential for its role in dNTP-induced dimerization. In contrast, defects in substrate specificity are not rescued in the double mutant, implying that functional sequence variation elsewhere in the protein is necessary. These findings yield insight into loop 2's roles in regulating RR specificity, allostery, and oligomerization.
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Danchin A. From chemical metabolism to life: the origin of the genetic coding process. Beilstein J Org Chem 2017; 13:1119-1135. [PMID: 28684991 PMCID: PMC5480338 DOI: 10.3762/bjoc.13.111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/19/2017] [Indexed: 12/11/2022] Open
Abstract
Looking for origins is so much rooted in ideology that most studies reflect opinions that fail to explore the first realistic scenarios. To be sure, trying to understand the origins of life should be based on what we know of current chemistry in the solar system and beyond. There, amino acids and very small compounds such as carbon dioxide, dihydrogen or dinitrogen and their immediate derivatives are ubiquitous. Surface-based chemical metabolism using these basic chemicals is the most likely beginning in which amino acids, coenzymes and phosphate-based small carbon molecules were built up. Nucleotides, and of course RNAs, must have come to being much later. As a consequence, the key question to account for life is to understand how chemical metabolism that began with amino acids progressively shaped into a coding process involving RNAs. Here I explore the role of building up complementarity rules as the first information-based process that allowed for the genetic code to emerge, after RNAs were substituted to surfaces to carry over the basic metabolic pathways that drive the pursuit of life.
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Affiliation(s)
- Antoine Danchin
- Institute of Cardiometabolism and Nutrition, Hôpital de la Pitié-Salpêtrière, 47 Boulevard de l'Hôpital, 75013, Paris, France
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Foskolou IP, Jorgensen C, Leszczynska KB, Olcina MM, Tarhonskaya H, Haisma B, D'Angiolella V, Myers WK, Domene C, Flashman E, Hammond EM. Ribonucleotide Reductase Requires Subunit Switching in Hypoxia to Maintain DNA Replication. Mol Cell 2017; 66:206-220.e9. [PMID: 28416140 PMCID: PMC5405111 DOI: 10.1016/j.molcel.2017.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 02/13/2017] [Accepted: 03/07/2017] [Indexed: 02/07/2023]
Abstract
Cells exposed to hypoxia experience replication stress but do not accumulate DNA damage, suggesting sustained DNA replication. Ribonucleotide reductase (RNR) is the only enzyme capable of de novo synthesis of deoxyribonucleotide triphosphates (dNTPs). However, oxygen is an essential cofactor for mammalian RNR (RRM1/RRM2 and RRM1/RRM2B), leading us to question the source of dNTPs in hypoxia. Here, we show that the RRM1/RRM2B enzyme is capable of retaining activity in hypoxia and therefore is favored over RRM1/RRM2 in order to preserve ongoing replication and avoid the accumulation of DNA damage. We found two distinct mechanisms by which RRM2B maintains hypoxic activity and identified responsible residues in RRM2B. The importance of RRM2B in the response to tumor hypoxia is further illustrated by correlation of its expression with a hypoxic signature in patient samples and its roles in tumor growth and radioresistance. Our data provide mechanistic insight into RNR biology, highlighting RRM2B as a hypoxic-specific, anti-cancer therapeutic target. RRM2B is induced in response to hypoxia in both cell models and patient datasets RRM2B retains activity in hypoxic conditions and is the favored RNR subunit in hypoxia Loss of RRM2B has detrimental consequences for cell fate, specifically in hypoxia RRM2B depletion enhanced hypoxic-specific apoptosis and increased radiosensitivity
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Affiliation(s)
- Iosifina P Foskolou
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Christian Jorgensen
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Katarzyna B Leszczynska
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Monica M Olcina
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Hanna Tarhonskaya
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Bauke Haisma
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Vincenzo D'Angiolella
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - William K Myers
- Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| | - Carmen Domene
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK; Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Emily Flashman
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Ester M Hammond
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK.
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41
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Fuller FD, Gul S, Chatterjee R, Burgie ES, Young ID, Lebrette H, Srinivas V, Brewster AS, Michels-Clark T, Clinger JA, Andi B, Ibrahim M, Pastor E, de Lichtenberg C, Hussein R, Pollock CJ, Zhang M, Stan CA, Kroll T, Fransson T, Weninger C, Kubin M, Aller P, Lassalle L, Bräuer P, Miller MD, Amin M, Koroidov S, Roessler CG, Allaire M, Sierra RG, Docker PT, Glownia JM, Nelson S, Koglin JE, Zhu D, Chollet M, Song S, Lemke H, Liang M, Sokaras D, Alonso-Mori R, Zouni A, Messinger J, Bergmann U, Boal AK, Bollinger JM, Krebs C, Högbom M, Phillips GN, Vierstra RD, Sauter NK, Orville AM, Kern J, Yachandra VK, Yano J. Drop-on-demand sample delivery for studying biocatalysts in action at X-ray free-electron lasers. Nat Methods 2017; 14:443-449. [PMID: 28250468 PMCID: PMC5376230 DOI: 10.1038/nmeth.4195] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/18/2017] [Indexed: 12/22/2022]
Abstract
X-ray crystallography at X-ray free-electron laser sources is a powerful method for studying macromolecules at biologically relevant temperatures. Moreover, when combined with complementary techniques like X-ray emission spectroscopy, both global structures and chemical properties of metalloenzymes can be obtained concurrently, providing insights into the interplay between the protein structure and dynamics and the chemistry at an active site. The implementation of such a multimodal approach can be compromised by conflicting requirements to optimize each individual method. In particular, the method used for sample delivery greatly affects the data quality. We present here a robust way of delivering controlled sample amounts on demand using acoustic droplet ejection coupled with a conveyor belt drive that is optimized for crystallography and spectroscopy measurements of photochemical and chemical reactions over a wide range of time scales. Studies with photosystem II, the phytochrome photoreceptor, and ribonucleotide reductase R2 illustrate the power and versatility of this method.
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Affiliation(s)
- Franklin D. Fuller
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ernest S. Burgie
- Department of Biology, Washington University in St. Louis, St.
Louis, Missouri 63130, USA
| | - Iris D. Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hugo Lebrette
- Department of Biochemistry and Biophysics, Stockholm University,
SE-106 91 Stockholm, Sweden
| | - Vivek Srinivas
- Department of Biochemistry and Biophysics, Stockholm University,
SE-106 91 Stockholm, Sweden
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Tara Michels-Clark
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Babak Andi
- National Synchrotron Light Source II, Brookhaven National
Laboratory, Upton, NY, 11973, USA
| | - Mohamed Ibrahim
- Institut für Biologie, Humboldt-Universität zu
Berlin, D-10099 Berlin, Germany
| | - Ernest Pastor
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Casper de Lichtenberg
- Institutionen för Kemi, Kemiskt Biologiskt Centrum,
Umeå Universitet, SE 90187 Umeå, Sweden
| | - Rana Hussein
- Institut für Biologie, Humboldt-Universität zu
Berlin, D-10099 Berlin, Germany
| | - Christopher J. Pollock
- Department of Chemistry, The Pennsylvania State University,
University Park, PA 16802, USA
| | - Miao Zhang
- Institut für Biologie, Humboldt-Universität zu
Berlin, D-10099 Berlin, Germany
| | - Claudiu A. Stan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory,
Menlo Park, CA 94025, USA
| | - Thomas Kroll
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Thomas Fransson
- Stanford PULSE Institute, SLAC National Accelerator Laboratory,
Menlo Park, CA 94025, USA
| | - Clemens Weninger
- Stanford PULSE Institute, SLAC National Accelerator Laboratory,
Menlo Park, CA 94025, USA
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Markus Kubin
- Institute for Methods and Instrumentation on Synchrotron Radiation
Research, Helmholtz Zentrum Berlin für Materialien und Energie GmbH, 12489
Berlin, Germany
| | - Pierre Aller
- Diamond Light Source Ltd, Harwell Science and Innovation Campus,
Didcot, OX110DE, UK
| | - Louise Lassalle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Philipp Bräuer
- Diamond Light Source Ltd, Harwell Science and Innovation Campus,
Didcot, OX110DE, UK
- Department of Biochemistry, University of Oxford, South Parks Road,
Oxford OX1 3QU, UK
| | | | - Muhamed Amin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sergey Koroidov
- Institutionen för Kemi, Kemiskt Biologiskt Centrum,
Umeå Universitet, SE 90187 Umeå, Sweden
- Stanford PULSE Institute, SLAC National Accelerator Laboratory,
Menlo Park, CA 94025, USA
| | - Christian G. Roessler
- National Synchrotron Light Source II, Brookhaven National
Laboratory, Upton, NY, 11973, USA
| | - Marc Allaire
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Raymond G. Sierra
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Peter T. Docker
- Diamond Light Source Ltd, Harwell Science and Innovation Campus,
Didcot, OX110DE, UK
| | - James M. Glownia
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Silke Nelson
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Jason E. Koglin
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Diling Zhu
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Matthieu Chollet
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Sanghoon Song
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Henrik Lemke
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Mengning Liang
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | | | | | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu
Berlin, D-10099 Berlin, Germany
| | - Johannes Messinger
- Institutionen för Kemi, Kemiskt Biologiskt Centrum,
Umeå Universitet, SE 90187 Umeå, Sweden
- Department of Chemistry – Ångström,
Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory,
Menlo Park, CA 94025, USA
| | - Amie K. Boal
- Department of Chemistry, The Pennsylvania State University,
University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania
State University, University Park, PA 16802, USA
| | - J. Martin Bollinger
- Department of Chemistry, The Pennsylvania State University,
University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania
State University, University Park, PA 16802, USA
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University,
University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania
State University, University Park, PA 16802, USA
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University,
SE-106 91 Stockholm, Sweden
- Department of Chemistry, Stanford University, Stanford, CA 94305,
USA
| | - George N. Phillips
- Department of BioSciences, Rice Univ. Houston, TX 77005, USA
- Department of Chemistry, Rice Univ. Houston, TX 77005, USA
| | - Richard D. Vierstra
- Department of Biology, Washington University in St. Louis, St.
Louis, Missouri 63130, USA
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Allen M. Orville
- Diamond Light Source Ltd, Harwell Science and Innovation Campus,
Didcot, OX110DE, UK
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA 94025,
USA
| | - Vittal K. Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, USA
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42
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Caforio A, Driessen AJM. Archaeal phospholipids: Structural properties and biosynthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1325-1339. [PMID: 28007654 DOI: 10.1016/j.bbalip.2016.12.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 01/06/2023]
Abstract
Phospholipids are major components of the cellular membranes present in all living organisms. They typically form a lipid bilayer that embroiders the cell or cellular organelles, constitute a barrier for ions and small solutes and form a matrix that supports the function of membrane proteins. The chemical composition of the membrane phospholipids present in the two prokaryotic domains Archaea and Bacteria are vastly different. Archaeal lipids are composed of highly-methylated isoprenoid chains that are ether-linked to a glycerol-1-phosphate backbone while bacterial phospholipids consist of straight fatty acids bound by ester bonds to the enantiomeric glycerol-3-phosphate backbone. The chemical structure of the archaeal lipids and their compositional diversity ensures the required stability at extreme environmental conditions as many archaea thrive at such conditions including high or low temperature, high salinity and extreme acidic or alkaline pH values. However, not all archaea are extremophiles, and the presence of ether-linked phospholipids is a phylogenetic marker that distinguishes Archaea from other life forms. During the past decade, our understanding of the biosynthesis of archaeal lipids has progressed resulting in the characterization of the main biosynthetic steps of the pathway including the reconstitution of lipid biosynthesis in vitro. Here we describe the chemical and physical properties of archaeal lipids and membranes derived thereof, summarize the existing knowledge about the enzymology of the archaeal lipid biosynthetic pathway and discuss evolutionary theories associated with the "Lipid Divide" that resulted in the differentiation of bacterial and archaeal organisms. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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Affiliation(s)
- Antonella Caforio
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands; The Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Arnold J M Driessen
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands; The Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.
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Crespo A, Pedraz L, Astola J, Torrents E. Pseudomonas aeruginosa Exhibits Deficient Biofilm Formation in the Absence of Class II and III Ribonucleotide Reductases Due to Hindered Anaerobic Growth. Front Microbiol 2016; 7:688. [PMID: 27242714 PMCID: PMC4860495 DOI: 10.3389/fmicb.2016.00688] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/26/2016] [Indexed: 01/11/2023] Open
Abstract
Chronic lung infections by the ubiquitous and extremely adaptable opportunistic pathogen Pseudomonas aeruginosa correlate with the formation of a biofilm, where bacteria grow in association with an extracellular matrix and display a wide range of changes in gene expression and metabolism. This leads to increased resistance to physical stress and antibiotic therapies, while enhancing cell-to-cell communication. Oxygen diffusion through the complex biofilm structure generates an oxygen concentration gradient, leading to the appearance of anaerobic microenvironments. Ribonucleotide reductases (RNRs) are a family of highly sophisticated enzymes responsible for the synthesis of the deoxyribonucleotides, and they constitute the only de novo pathway for the formation of the building blocks needed for DNA synthesis and repair. P. aeruginosa is one of the few bacteria encoding all three known RNR classes (Ia, II, and III). Class Ia RNRs are oxygen dependent, class II are oxygen independent, and class III are oxygen sensitive. A tight control of RNR activity is essential for anaerobic growth and therefore for biofilm development. In this work we explored the role of the different RNR classes in biofilm formation under aerobic and anaerobic initial conditions and using static and continuous-flow biofilm models. We demonstrated the importance of class II and III RNR for proper cell division in biofilm development and maturation. We also determined that these classes are transcriptionally induced during biofilm formation and under anaerobic conditions. The molecular mechanism of their anaerobic regulation was also studied, finding that the Anr/Dnr system is responsible for class II RNR induction. These data can be integrated with previous knowledge about biofilms in a model where these structures are understood as a set of layers determined by oxygen concentration and contain cells with different RNR expression profiles, bringing us a step closer to the understanding of this complex growth pattern, essential for P. aeruginosa chronic infections.
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Affiliation(s)
- Anna Crespo
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia Barcelona, Spain
| | - Lucas Pedraz
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia Barcelona, Spain
| | - Josep Astola
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia Barcelona, Spain
| | - Eduard Torrents
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia Barcelona, Spain
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Structural Mechanism of Allosteric Activity Regulation in a Ribonucleotide Reductase with Double ATP Cones. Structure 2016; 24:906-17. [PMID: 27133024 DOI: 10.1016/j.str.2016.03.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 11/22/2022]
Abstract
Ribonucleotide reductases (RNRs) reduce ribonucleotides to deoxyribonucleotides. Their overall activity is stimulated by ATP and downregulated by dATP via a genetically mobile ATP cone domain mediating the formation of oligomeric complexes with varying quaternary structures. The crystal structure and solution X-ray scattering data of a novel dATP-induced homotetramer of the Pseudomonas aeruginosa class I RNR reveal the structural bases for its unique properties, namely one ATP cone that binds two dATP molecules and a second one that is non-functional, binding no nucleotides. Mutations in the observed tetramer interface ablate oligomerization and dATP-induced inhibition but not the ability to bind dATP. Sequence analysis shows that the novel type of ATP cone may be widespread in RNRs. The present study supports a scenario in which diverse mechanisms for allosteric activity regulation are gained and lost through acquisition and evolutionary erosion of different types of ATP cone.
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The TIM Barrel Architecture Facilitated the Early Evolution of Protein-Mediated Metabolism. J Mol Evol 2016; 82:17-26. [PMID: 26733481 PMCID: PMC4709378 DOI: 10.1007/s00239-015-9722-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 11/11/2015] [Indexed: 12/30/2022]
Abstract
The triosephosphate isomerase (TIM) barrel protein fold is a structurally repetitive architecture that is present in approximately 10 % of all enzymes. It is generally assumed that this ubiquity in modern proteomes reflects an essential historical role in early protein-mediated metabolism. Here, we provide quantitative and comparative analyses to support several hypotheses about the early importance of the TIM barrel architecture. An information theoretical analysis of protein structures supports the hypothesis that the TIM barrel architecture could arise more easily by duplication and recombination compared to other mixed α/β structures. We show that TIM barrel enzymes corresponding to the most taxonomically broad superfamilies also have the broadest range of functions, often aided by metal and nucleotide-derived cofactors that are thought to reflect an earlier stage of metabolic evolution. By comparison to other putatively ancient protein architectures, we find that the functional diversity of TIM barrel proteins cannot be explained simply by their antiquity. Instead, the breadth of TIM barrel functions can be explained, in part, by the incorporation of a broad range of cofactors, a trend that does not appear to be shared by proteins in general. These results support the hypothesis that the simple and functionally general TIM barrel architecture may have arisen early in the evolution of protein biosynthesis and provided an ideal scaffold to facilitate the metabolic transition from ribozymes, peptides, and geochemical catalysts to modern protein enzymes.
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The RNA World: 4,000,000,050 years old. Life (Basel) 2015; 5:1583-6. [PMID: 26791312 PMCID: PMC4695837 DOI: 10.3390/life5041583] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 12/26/2022] Open
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Crona M, Hofer A, Astorga-Wells J, Sjöberg BM, Tholander F. Biochemical Characterization of the Split Class II Ribonucleotide Reductase from Pseudomonas aeruginosa. PLoS One 2015. [PMID: 26225432 PMCID: PMC4520616 DOI: 10.1371/journal.pone.0134293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa can grow under both aerobic and anaerobic conditions. Its flexibility with respect to oxygen load is reflected by the fact that its genome encodes all three existing classes of ribonucleotides reductase (RNR): the oxygen-dependent class I RNR, the oxygen-indifferent class II RNR, and the oxygen-sensitive class III RNR. The P. aeruginosa class II RNR is expressed as two separate polypeptides (NrdJa and NrdJb), a unique example of a split RNR enzyme in a free-living organism. A split class II RNR is also found in a few closely related γ-Proteobacteria. We have characterized the P. aeruginosa class II RNR and show that both subunits are required for formation of a biologically functional enzyme that can sustain vitamin B12-dependent growth. Binding of the B12 coenzyme as well as substrate and allosteric effectors resides in the NrdJa subunit, whereas the NrdJb subunit mediates efficient reductive dithiol exchange during catalysis. A combination of activity assays and activity-independent methods like surface plasmon resonance and gas phase electrophoretic macromolecule analysis suggests that the enzymatically active form of the enzyme is a (NrdJa-NrdJb)2 homodimer of heterodimers, and a combination of hydrogen-deuterium exchange experiments and molecular modeling suggests a plausible region in NrdJa that interacts with NrdJb. Our detailed characterization of the split NrdJ from P. aeruginosa provides insight into the biochemical function of a unique enzyme known to have central roles in biofilm formation and anaerobic growth.
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Affiliation(s)
- Mikael Crona
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, SE-17177, Stockholm, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187, Umeå, Sweden
| | - Juan Astorga-Wells
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, SE-17177, Stockholm, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691, Stockholm, Sweden
| | - Fredrik Tholander
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 2, SE-17177, Stockholm, Sweden
- * E-mail:
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Jonna VR, Crona M, Rofougaran R, Lundin D, Johansson S, Brännström K, Sjöberg BM, Hofer A. Diversity in Overall Activity Regulation of Ribonucleotide Reductase. J Biol Chem 2015; 290:17339-48. [PMID: 25971975 DOI: 10.1074/jbc.m115.649624] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Indexed: 12/11/2022] Open
Abstract
Ribonucleotide reductase (RNR) catalyzes the reduction of ribonucleotides to the corresponding deoxyribonucleotides, which are used as building blocks for DNA replication and repair. This process is tightly regulated via two allosteric sites, the specificity site (s-site) and the overall activity site (a-site). The a-site resides in an N-terminal ATP cone domain that binds dATP or ATP and functions as an on/off switch, whereas the composite s-site binds ATP, dATP, dTTP, or dGTP and determines which substrate to reduce. There are three classes of RNRs, and class I RNRs consist of different combinations of α and β subunits. In eukaryotic and Escherichia coli class I RNRs, dATP inhibits enzyme activity through the formation of inactive α6 and α4β4 complexes, respectively. Here we show that the Pseudomonas aeruginosa class I RNR has a duplicated ATP cone domain and represents a third mechanism of overall activity regulation. Each α polypeptide binds three dATP molecules, and the N-terminal ATP cone is critical for binding two of the dATPs because a truncated protein lacking this cone could only bind dATP to its s-site. ATP activates the enzyme solely by preventing dATP from binding. The dATP-induced inactive form is an α4 complex, which can interact with β2 to form a non-productive α4β2 complex. Other allosteric effectors induce a mixture of α2 and α4 forms, with the former being able to interact with β2 to form active α2β2 complexes. The unique features of the P. aeruginosa RNR are interesting both from evolutionary and drug discovery perspectives.
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Affiliation(s)
- Venkateswara Rao Jonna
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå and
| | - Mikael Crona
- the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Reza Rofougaran
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå and
| | - Daniel Lundin
- the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Samuel Johansson
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå and
| | - Kristoffer Brännström
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå and
| | - Britt-Marie Sjöberg
- the Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Anders Hofer
- From the Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå and
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