1
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Santema LL, Rotilio L, Xiang R, Tjallinks G, Guallar V, Mattevi A, Fraaije MW. Discovery and biochemical characterization of thermostable glycerol oxidases. Appl Microbiol Biotechnol 2024; 108:61. [PMID: 38183484 PMCID: PMC10771423 DOI: 10.1007/s00253-023-12883-9] [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: 06/23/2023] [Revised: 10/10/2023] [Accepted: 10/20/2023] [Indexed: 01/08/2024]
Abstract
Alditol oxidases are promising tools for the biocatalytic oxidation of glycerol to more valuable chemicals. By integrating in silico bioprospecting with cell-free protein synthesis and activity screening, an effective pipeline was developed to rapidly identify enzymes that are active on glycerol. Three thermostable alditol oxidases from Actinobacteria Bacterium, Streptomyces thermoviolaceus, and Thermostaphylospora chromogena active on glycerol were discovered. The characterization of these three flavoenzymes demonstrated their glycerol oxidation activities, preference for alkaline conditions, and excellent thermostabilities with melting temperatures higher than 75 °C. Structural elucidation of the alditol oxidase from Actinobacteria Bacterium highlighted a constellation of side chains that engage the substrate through several hydrogen bonds, a histidine residue covalently bound to the FAD prosthetic group, and a tunnel leading to the active site. Upon computational simulations of substrate binding, a double mutant targeting a residue pair at the tunnel entrance was created and found to display an improved thermal stability and catalytic efficiency for glycerol oxidation. The hereby described alditol oxidases form a valuable panel of oxidative biocatalysts that can perform regioselective oxidation of glycerol and other polyols. KEY POINTS: • Rapid pipeline designed to identify putative oxidases • Biochemical and structural characterization of alditol oxidases • Glycerol oxidation to more valuable derivatives.
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Affiliation(s)
- Lars L Santema
- Molecular Enzymology, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Laura Rotilio
- Department of Biology and Biotechnology, University of Pavia, via Ferrata 9, 27100, Pavia, Italy
| | - Ruite Xiang
- Barcelona Supercomputing Center (BSC), Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08034, Spain
| | - Gwen Tjallinks
- Molecular Enzymology, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Victor Guallar
- Barcelona Supercomputing Center (BSC), Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08034, Spain.
| | - Andrea Mattevi
- Department of Biology and Biotechnology, University of Pavia, via Ferrata 9, 27100, Pavia, Italy.
| | - Marco W Fraaije
- Molecular Enzymology, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
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2
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Baumgartner JT, McCaughey CS, Fleming HS, Lentz AR, Sanchez LM, McKinnie SMK. Vanadium-dependent haloperoxidases from diverse microbes halogenate exogenous alkyl quinolone quorum sensing signals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.31.606109. [PMID: 39131370 PMCID: PMC11312541 DOI: 10.1101/2024.07.31.606109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Site-selective vanadium-dependent haloperoxidases (VHPOs) are a unique enzyme family that catalyze selective halogenation reactions previously characterized within bacterial natural product biosynthetic pathways. However, the broader chemical roles and biological distribution of these halogenases remains to be explored. Using bioinformatic methods, we have defined a VHPO subfamily that regioselectively brominates alkyl quinolone (AQ) quorum sensing molecules. In vitro AQ halogenation activity was demonstrated from phylogenetically distinct bacteria lacking established AQ biosynthetic pathways and sourced from diverse environments. AQ-VHPOs show high sequence and biochemical similarities with negligible genomic synteny or biosynthetic gene cluster co-localization. Exposure of VHPO-containing microbes to synthetic AQs or established bacterial producers identifies the chemical and spatial response to subvert their bacteriostatic effects. The characterization of novel homologs from bacterial taxa without previously demonstrated vanadium enzymology suggests VHPO-mediated AQ bromination is a niche to manipulate the chemical ecology of microbial communities. Table of Contents Graphic Synopsis A broadly distributed subfamily of bacterial site-selective VHPOs provides protection against exogenously encountered bacteriostatic alkyl quinolone quorum sensing signals.
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3
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Vorländer MK, Rothe P, Kleifeld J, Cormack ED, Veleti L, Riabov-Bassat D, Fin L, Phillips AW, Cochella L, Plaschka C. Mechanism for the initiation of spliceosome disassembly. Nature 2024; 632:443-450. [PMID: 38925148 DOI: 10.1038/s41586-024-07741-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 06/19/2024] [Indexed: 06/28/2024]
Abstract
Precursor-mRNA (pre-mRNA) splicing requires the assembly, remodelling and disassembly of the multi-megadalton ribonucleoprotein complex called the spliceosome1. Recent studies have shed light on spliceosome assembly and remodelling for catalysis2-6, but the mechanism of disassembly remains unclear. Here we report cryo-electron microscopy structures of nematode and human terminal intron lariat spliceosomes along with biochemical and genetic data. Our results uncover how four disassembly factors and the conserved RNA helicase DHX15 initiate spliceosome disassembly. The disassembly factors probe large inner and outer spliceosome surfaces to detect the release of ligated mRNA. Two of these factors, TFIP11 and C19L1, and three general spliceosome subunits, SYF1, SYF2 and SDE2, then dock and activate DHX15 on the catalytic U6 snRNA to initiate disassembly. U6 therefore controls both the start5 and end of pre-mRNA splicing. Taken together, our results explain the molecular basis of the initiation of canonical spliceosome disassembly and provide a framework to understand general spliceosomal RNA helicase control and the discard of aberrant spliceosomes.
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Affiliation(s)
- Matthias K Vorländer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Patricia Rothe
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Justus Kleifeld
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Eric D Cormack
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lalitha Veleti
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Daria Riabov-Bassat
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Laura Fin
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Alex W Phillips
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Luisa Cochella
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Clemens Plaschka
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
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4
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Umuhire Juru A, Ghirlando R, Zhang J. Structural basis of tRNA recognition by the widespread OB fold. Nat Commun 2024; 15:6385. [PMID: 39075051 PMCID: PMC11286949 DOI: 10.1038/s41467-024-50730-1] [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: 03/28/2024] [Accepted: 07/18/2024] [Indexed: 07/31/2024] Open
Abstract
The widespread oligonucleotide/oligosaccharide-binding (OB)-fold recognizes diverse substrates from sugars to nucleic acids and proteins, and plays key roles in genome maintenance, transcription, translation, and tRNA metabolism. OB-containing bacterial Trbp and yeast Arc1p proteins are thought to recognize the tRNA elbow or anticodon regions. Here we report a 2.6 Å co-crystal structure of Aquifex aeolicus Trbp111 bound to tRNAIle, which reveals that Trbp recognizes tRNAs solely by capturing their 3' ends. Structural, mutational, and biophysical analyses show that the Trbp/EMAPII-like OB fold precisely recognizes the single-stranded structure, 3' terminal location, and specific sequence of the 3' CA dinucleotide - a universal feature of mature tRNAs. Arc1p supplements its OB - tRNA 3' end interaction with additional contacts that involve an adjacent basic region and the tRNA body. This study uncovers a previously unrecognized mode of tRNA recognition by an ancient protein fold, and provides insights into protein-mediated tRNA aminoacylation, folding, localization, trafficking, and piracy.
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Affiliation(s)
- Aline Umuhire Juru
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA.
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5
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Silverio MP, Neumann T, Schaubruch K, Heermann R, Pérez-García P, Chow J, Streit WR. Metagenome-derived SusD-homologs affiliated with Bacteroidota bind to synthetic polymers. Appl Environ Microbiol 2024; 90:e0093324. [PMID: 38953372 PMCID: PMC11267923 DOI: 10.1128/aem.00933-24] [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: 05/17/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024] Open
Abstract
Starch utilization system (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the sus operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics. IMPORTANCE SusD1 and SusD38489 can be considered for further applications regarding their putative adsorption toward fossil-fuel based polymers. This is the first time that SusD homologs from the polysaccharide utilization loci (PUL), largely described for the phylum Bacteroidota, are characterized as synthetic polymer-binding proteins.
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Affiliation(s)
| | - Tabea Neumann
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Kirsten Schaubruch
- Institute of Molecular Physiology, Johannes-Gutenberg University of Mainz, Mainz, Germany
| | - Ralf Heermann
- Institute of Molecular Physiology, Johannes-Gutenberg University of Mainz, Mainz, Germany
| | - Pablo Pérez-García
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Wolfgang R. Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
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6
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Mevissen TE, Kümmecke M, Schmid EW, Farnung L, Walter JC. STK19 positions TFIIH for cell-free transcription-coupled DNA repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.22.604623. [PMID: 39091863 PMCID: PMC11291053 DOI: 10.1101/2024.07.22.604623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
In transcription-coupled repair, stalled RNA polymerase II (Pol II) is recognized by CSB and CRL4CSA, which co-operate with UVSSSA and ELOF1 to recruit TFIIH for nucleotide excision repair (TC-NER). To explore the mechanism of TC-NER, we recapitulated this reaction in vitro. When a plasmid containing a site-specific lesion is transcribed in frog egg extract, error-free repair is observed that depends on CSB, CRL4CSA, UVSSA, and ELOF1. Repair also depends on STK19, a factor previously implicated in transcription recovery after UV exposure. A 1.9 Å cryo-electron microscopy structure shows that STK19 joins the TC-NER complex by binding CSA and the RPB1 subunit of Pol II. Furthermore, AlphaFold predicts that STK19 interacts with the XPD subunit of TFIIH, and disrupting this interface impairs cell-free repair. Molecular modeling suggests that STK19 positions TFIIH ahead of Pol II for lesion verification. In summary, our analysis of cell-free TC-NER suggests that STK19 couples RNA polymerase II stalling to downstream repair events.
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Affiliation(s)
- Tycho E.T. Mevissen
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute
| | - Maximilian Kümmecke
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ernst W. Schmid
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Lucas Farnung
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Johannes C. Walter
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute
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7
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Beugelink JW, Hóf H, Janssen BJC. CRTAC1 has a Compact β-propeller-TTR Core Stabilized by Potassium Ions. J Mol Biol 2024; 436:168712. [PMID: 39029889 DOI: 10.1016/j.jmb.2024.168712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/21/2024]
Abstract
Cartilage acidic protein-1 (CRTAC1) is a secreted glycoprotein with roles in development, function and repair of the nervous system. It is linked to ischemic stroke, osteoarthritis and (long) COVID outcomes, and has suppressive activity in carcinoma and bladder cancer. Structural characterization of CRTAC1 has been complicated by its tendency to form disulfide-linked aggregates. Here, we show that CRTAC1 is stabilized by potassium ions. Using x-ray crystallography, we determined the structure of CRTAC1 to 1.6 Å. This reveals that the protein consists of a three-domain fold, including a previously-unreported compact β-propeller-TTR combination, in which an extended loop of the TTR plugs the β-propeller core. Electron density is observed for ten bound ions: six calcium, three potassium and one sodium. Low potassium ion concentrations lead to changes in tryptophan environment and exposure of two buried free cysteines located on a β-blade and in the β-propeller-plugging TTR loop. Mutating the two free cysteines to serines prevents covalent intermolecular interactions, but not aggregation, in absence of potassium ions. The potassium ion binding sites are located between the blades of the β-propeller, explaining their importance for the stability of the CRTAC1 fold. Despite varying in sequence, the three potassium ion binding sites are structurally similar and conserved features of the CRTAC protein family. These insights into the stability and structure of CRTAC1 provide a basis for further work into the function of CRTAC1 in health and disease.
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Affiliation(s)
- J Wouter Beugelink
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands
| | - Henrietta Hóf
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands
| | - Bert J C Janssen
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands.
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8
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Mance L, Bigot N, Zhamungui Sánchez E, Coste F, Martín-González N, Zentout S, Biliškov M, Pukało Z, Mishra A, Chapuis C, Arteni AA, Lateur A, Goffinont S, Gaudon V, Talhaoui I, Casuso I, Beaufour M, Garnier N, Artzner F, Cadene M, Huet S, Castaing B, Suskiewicz MJ. Dynamic BTB-domain filaments promote clustering of ZBTB proteins. Mol Cell 2024; 84:2490-2510.e9. [PMID: 38996459 DOI: 10.1016/j.molcel.2024.05.029] [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: 07/28/2023] [Revised: 04/11/2024] [Accepted: 05/31/2024] [Indexed: 07/14/2024]
Abstract
The formation of dynamic protein filaments contributes to various biological functions by clustering individual molecules together and enhancing their binding to ligands. We report such a propensity for the BTB domains of certain proteins from the ZBTB family, a large eukaryotic transcription factor family implicated in differentiation and cancer. Working with Xenopus laevis and human proteins, we solved the crystal structures of filaments formed by dimers of the BTB domains of ZBTB8A and ZBTB18 and demonstrated concentration-dependent higher-order assemblies of these dimers in solution. In cells, the BTB-domain filamentation supports clustering of full-length human ZBTB8A and ZBTB18 into dynamic nuclear foci and contributes to the ZBTB18-mediated repression of a reporter gene. The BTB domains of up to 21 human ZBTB family members and two related proteins, NACC1 and NACC2, are predicted to behave in a similar manner. Our results suggest that filamentation is a more common feature of transcription factors than is currently appreciated.
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Affiliation(s)
- Lucija Mance
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Nicolas Bigot
- Université Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, BIOSIT - UAR3480, 35000 Rennes, France
| | - Edison Zhamungui Sánchez
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Franck Coste
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France.
| | - Natalia Martín-González
- Aix-Marseille Université, INSERM, DyNaMo, Turing Centre for Living Systems (CENTURI), 13288 Marseille Cedex 09, France; Aix-Marseille Université, CNRS, AFMB UMR 7257, 13288 Marseille Cedex 09, France
| | - Siham Zentout
- Université Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, BIOSIT - UAR3480, 35000 Rennes, France
| | - Marin Biliškov
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Zofia Pukało
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Aanchal Mishra
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Catherine Chapuis
- Université Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, BIOSIT - UAR3480, 35000 Rennes, France
| | - Ana-Andreea Arteni
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Cryo-Electron Microscopy Facility, CRYOEM-Gif, 91198 Gif-sur-Yvette, France
| | - Axelle Lateur
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Stéphane Goffinont
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Virginie Gaudon
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Ibtissam Talhaoui
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Ignacio Casuso
- Aix-Marseille Université, INSERM, DyNaMo, Turing Centre for Living Systems (CENTURI), 13288 Marseille Cedex 09, France
| | - Martine Beaufour
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Norbert Garnier
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Franck Artzner
- Université Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, 35000 Rennes, France
| | - Martine Cadene
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Sébastien Huet
- Université Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, BIOSIT - UAR3480, 35000 Rennes, France; Institut Universitaire de France, 75005 Paris, France
| | - Bertrand Castaing
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France
| | - Marcin Józef Suskiewicz
- Centre de Biophysique Moléculaire (CBM), UPR 4301, CNRS, affiliated with Université d'Orléans, 45071 Orléans Cedex 2, France.
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9
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Figueroa Blanco DR, Vidossich P, De Vivo M. Correct Nucleotide Selection Is Confined at the Binding Site of Polymerase Enzymes. J Chem Inf Model 2024; 64:5285-5294. [PMID: 38901009 DOI: 10.1021/acs.jcim.4c00696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
DNA polymerases (Pols) add incoming nucleotides (deoxyribonucleoside triphosphate (dNTPs)) to growing DNA strands, a crucial step for DNA synthesis. The insertion of correct (vs incorrect) nucleotides relates to Pols' fidelity, which defines Pols' ability to faithfully replicate DNA strands in a template-dependent manner. We and others have demonstrated that reactant alignment and correct base pairing at the Pols catalytic site are crucial structural features to fidelity. Here, we first used equilibrium molecular simulations to demonstrate that the local dynamics at the protein-DNA interface in the proximity of the catalytic site is different when correct vs incorrect dNTPs are bound to polymerase β (Pol β). Formation and dynamic stability of specific interatomic interactions around the incoming nucleotide influence the overall binding site architecture. This explains why certain Pols' mutants can affect the local catalytic environment and influence the selection of correct vs incorrect nucleotides. In particular, this is here demonstrated by analyzing the interaction network formed by the residue R283, whose mutant R283A has an experimentally measured lower capacity of differentiating correct (G:dCTP) vs incorrect (G:dATP) base pairing in Pol β. We also used alchemical free-energy calculations to quantify the G:dCTP →G:dATP transformation in Pol β wild-type and mutant R283A. These results correlate well with the experimental trend, thus corroborating our mechanistic insights. Sequence and structural comparisons with other Pols from the same family suggest that these findings may also be valid in similar enzymes.
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Affiliation(s)
- David Ricardo Figueroa Blanco
- Laboratory of Molecular Modelling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, Genoa 16163, Italy
| | - Pietro Vidossich
- Laboratory of Molecular Modelling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, Genoa 16163, Italy
| | - Marco De Vivo
- Laboratory of Molecular Modelling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, Genoa 16163, Italy
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10
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Kurata T, Takegawa M, Ohira T, Syroegin EA, Atkinson GC, Johansson MJO, Polikanov YS, Garcia-Pino A, Suzuki T, Hauryliuk V. Toxic Small Alarmone Synthetase FaRel2 inhibits translation by pyrophosphorylating tRNA Gly and tRNA Thr. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602228. [PMID: 39005314 PMCID: PMC11245113 DOI: 10.1101/2024.07.05.602228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Translation-targeting toxic Small Alarmone Synthetases (toxSAS) are effectors of bacterial Toxin-Antitoxin systems that pyrophosphorylate the 3'-CCA end of tRNA to prevent aminoacylation. toxSAS are implicated in antiphage immunity: phage detection triggers the toxSAS activity to shut down viral production. We show that the toxSAS FaRel2 inspects the tRNA acceptor stem to specifically select tRNAGly and tRNAThr. The 1st, 2nd, 4th and 5th base pairs the stem act as the specificity determinants. We show that the toxSASs PhRel2 and CapRelSJ46 differ in tRNA specificity from FaRel2, and rationalise this through structural modelling: while the universal 3'-CCA end slots into a highly conserved CCA recognition groove, the acceptor stem recognition region is variable across toxSAS diversity. As phages use tRNA isoacceptors to overcome tRNA-targeting defences, we hypothesise that highly evolvable modular tRNA recognition allows for the escape of viral countermeasures through tRNA substrate specificity switching.
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Affiliation(s)
- Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Masaki Takegawa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Takayuki Ohira
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Egor A Syroegin
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | | | - Yury S Polikanov
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, (1C4 203), 1050 Brussels, Belgium
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, Tartu, Estonia
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11
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Hameleers L, Gaenssle LA, Bertran‐Llorens S, Pijning T, Jurak E. Polysaccharide utilization loci encoded DUF1735 likely functions as membrane-bound spacer for carbohydrate active enzymes. FEBS Open Bio 2024; 14:1133-1146. [PMID: 38735878 PMCID: PMC11216935 DOI: 10.1002/2211-5463.13816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/17/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024] Open
Abstract
Proteins featuring the Domain of Unknown Function 1735 are frequently found in Polysaccharide Utilization Loci, yet their role remains unknown. The domain and vicinity analyzer programs we developed mine the Kyoto Encyclopedia of Genes and Genomes and UniProt to enhance the functional prediction of DUF1735. Our datasets confirmed the exclusive presence of DUF1735 in Bacteroidota genomes, with Bacteroidetes thetaiotaomicron harboring 46 copies. Notably, 97.8% of DUF1735 are encoded in PULs, and 89% are N-termini of multimodular proteins featuring C-termini like Laminin_G_3, F5/8-typeC, and GH18 domains. Predominantly possessing a predicted lipoprotein signal peptide and sharing an immunoglobulin-like β-sandwich fold with the BACON domain and the N-termini of SusE/F, DUF1735 likely functions as N-terminal, membrane-bound spacer for diverse C-termini involved in PUL-mediated carbohydrate utilization.
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Affiliation(s)
- Lisanne Hameleers
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
| | - Lucie A. Gaenssle
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
| | | | - Tjaard Pijning
- Department of Biomolecular X‐ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenThe Netherlands
| | - Edita Jurak
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
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12
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Behlendorf C, Diwo M, Neumann-Schaal M, Fuchs M, Körner D, Jänsch L, Faber F, Blankenfeldt W. Formation of the pyruvoyl-dependent proline reductase Prd from Clostridioides difficile requires the maturation enzyme PrdH. PNAS NEXUS 2024; 3:pgae249. [PMID: 38979079 PMCID: PMC11229817 DOI: 10.1093/pnasnexus/pgae249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 06/09/2024] [Indexed: 07/10/2024]
Abstract
Stickland fermentation, the coupled oxidation and reduction of amino acid pairs, is a major pathway for obtaining energy in the nosocomial bacterium Clostridioides difficile. D-proline is the preferred substrate for the reductive path, making it not only a key component of the general metabolism but also impacting on the expression of the clostridial toxins TcdA and TcdB. D-proline reduction is catalyzed by the proline reductase Prd, which belongs to the pyruvoyl-dependent enzymes. These enzymes are translated as inactive proenzymes and require subsequent processing to install the covalently bound pyruvate. Whereas pyruvoyl formation by intramolecular serinolysis has been studied in unrelated enzymes, details about pyruvoyl generation by cysteinolysis as in Prd are lacking. Here, we show that Prd maturation requires a small dimeric protein that we have named PrdH. PrdH (CD630_32430) is co-encoded with the PrdA and PrdB subunits of Prd and also found in species producing similar reductases. By producing stable variants of PrdA and PrdB, we demonstrate that PrdH-mediated cleavage and pyruvoyl formation in the PrdA subunit requires PrdB, which can be harnessed to produce active recombinant Prd for subsequent analyses. We further created PrdA- and PrdH-mutants to get insight into the interaction of the components and into the processing reaction itself. Finally, we show that deletion of prdH renders C. difficile insensitive to proline concentrations in culture media, suggesting that this processing factor is essential for proline utilization. Due to the link between Stickland fermentation and pathogenesis, we suggest PrdH may be an attractive target for drug development.
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Affiliation(s)
- Christian Behlendorf
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Maurice Diwo
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Meina Neumann-Schaal
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, 38124 Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Manuela Fuchs
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany
- Faculty of Medicine, Institute for Molecular Infection Biology (IMIB), Julius-Maximilians-University of Würzburg (JMU), 97080 Würzburg, Germany
| | - Dominik Körner
- Cellular Proteomics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Lothar Jänsch
- Cellular Proteomics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Franziska Faber
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany
- Faculty of Medicine, Institute for Molecular Infection Biology (IMIB), Julius-Maximilians-University of Würzburg (JMU), 97080 Würzburg, Germany
| | - Wulf Blankenfeldt
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, 38106 Braunschweig, Germany
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13
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Datler J, Hansen JM, Thader A, Schlögl A, Bauer LW, Hodirnau VV, Schur FKM. Multi-modal cryo-EM reveals trimers of protein A10 to form the palisade layer in poxvirus cores. Nat Struct Mol Biol 2024; 31:1114-1123. [PMID: 38316877 PMCID: PMC11257981 DOI: 10.1038/s41594-023-01201-6] [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: 06/11/2023] [Accepted: 12/06/2023] [Indexed: 02/07/2024]
Abstract
Poxviruses are among the largest double-stranded DNA viruses, with members such as variola virus, monkeypox virus and the vaccination strain vaccinia virus (VACV). Knowledge about the structural proteins that form the viral core has remained sparse. While major core proteins have been annotated via indirect experimental evidence, their structures have remained elusive and they could not be assigned to individual core features. Hence, which proteins constitute which layers of the core, such as the palisade layer and the inner core wall, has remained enigmatic. Here we show, using a multi-modal cryo-electron microscopy (cryo-EM) approach in combination with AlphaFold molecular modeling, that trimers formed by the cleavage product of VACV protein A10 are the key component of the palisade layer. This allows us to place previously obtained descriptions of protein interactions within the core wall into perspective and to provide a detailed model of poxvirus core architecture. Importantly, we show that interactions within A10 trimers are likely generalizable over members of orthopox- and parapoxviruses.
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Affiliation(s)
- Julia Datler
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Jesse M Hansen
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Andreas Thader
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Alois Schlögl
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Lukas W Bauer
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | | | - Florian K M Schur
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.
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14
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Hsiao C, Tsai T, Shen T, Tsai Y, Liao Y, Lee Y, Tsai P. Characterization of a novel TFG variant causing autosomal recessive pure hereditary spastic paraplegia. Ann Clin Transl Neurol 2024; 11:1909-1920. [PMID: 38837630 PMCID: PMC11251477 DOI: 10.1002/acn3.52113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/03/2024] [Accepted: 05/15/2024] [Indexed: 06/07/2024] Open
Abstract
OBJECTIVE TFG mutations have previously been implicated in autosomal recessive hereditary spastic paraplegia (HSP), also known as SPG57. This study aimed to investigate the clinical and molecular features of TFG mutations in a Taiwanese HSP cohort. METHODS Genetic analysis of TFG was conducted in 242 unrelated Taiwanese HSP patients using a targeted resequencing panel covering the entire coding regions of TFG. Functional assays were performed using an in vitro cell model to assess the impact of TFG variants on protein function. Additionally, other representative TFG mutant proteins were examined to understand the broader implications of TFG mutations in HSP. RESULTS The study identified a novel homozygous TFG c.177A>C (p.(Lys59Asn)) variant in a family with adolescent-onset, pure form HSP. Functional analysis revealed that the Lys59Asn TFG variant, similar to other HSP-associated TFG mutants, exhibited a low affinity between TFG monomers and abnormal assembly of TFG homo-oligomers. These structural alterations led to aberrant intracellular distribution, compromising TFG's protein secretion function and resulting in decreased cellular viability. INTERPRETATION These findings confirm that the homozygous TFG c.177A>C (p.(Lys59Asn)) variant is a novel cause of SPG57. The study expands our understanding of the clinical and mutational spectrum of TFG-associated diseases, highlighting the functional defects associated with this specific TFG variant. Overall, this research contributes to the broader comprehension of the genetic and molecular mechanisms underlying HSP.
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Affiliation(s)
- Cheng‐Tsung Hsiao
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
| | - Tzu‐Yun Tsai
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
| | - Ting‐Yi Shen
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
| | - Yu‐Shuen Tsai
- Cancer and Immunology Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Yi‐Chu Liao
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Yi‐Chung Lee
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
- Center for Intelligent Drug Systems and Smart Bio‐devices (IDS2B)National Yang Ming Chiao Tung UniversityHsinchuTaiwan
| | - Pei‐Chien Tsai
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
- The iEGG and Animal Biotechnology Research CenterNational Chung Hsing UniversityTaichungTaiwan
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15
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Watanabe N, Savchenko A. Molecular insights into the initiation step of the Rcs signaling pathway. Structure 2024:S0969-2126(24)00221-1. [PMID: 38964336 DOI: 10.1016/j.str.2024.06.003] [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: 12/07/2023] [Revised: 04/05/2024] [Accepted: 06/07/2024] [Indexed: 07/06/2024]
Abstract
The Rcs pathway is repressed by the inner membrane protein IgaA under non-stressed conditions. This repression is hypothesized to be relieved by the binding of the outer membrane-anchored RcsF to IgaA. However, the precise mechanism by which RcsF binding triggers the signaling remains unclear. Here, we present the 1.8 Å resolution crystal structure capturing the interaction between IgaA and RcsF. Our comparative structural analysis, examining both the bound and unbound states of the periplasmic domain of IgaA (IgaAp), highlights rotational flexibility within IgaAp. Conversely, the conformation of RcsF remains unchanged upon binding. Our in vivo and in vitro studies do not support the model of a stable complex involving RcsF, IgaAp, and RcsDp. Instead, we demonstrate that the elements beyond IgaAp play a role in the interaction between IgaA and RcsD. These findings collectively allow us to propose a potential mechanism for the signaling across the inner membrane through IgaA.
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Affiliation(s)
- Nobuhiko Watanabe
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada; Center for Structural Biology for Infectious Diseases (CSBID) Chicago, IL, USA
| | - Alexei Savchenko
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada; Center for Structural Biology for Infectious Diseases (CSBID) Chicago, IL, USA.
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16
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Sharkia R, Zalan A, Kessel A, Al-Shareef W, Zahalka H, Hengel H, Schöls L, Azem A, Mahajnah M. SCAPER-Related Autosomal Recessive Retinitis Pigmentosa with Intellectual Disability: Confirming and Extending the Phenotypic Spectrum and Bioinformatics Analyses. Genes (Basel) 2024; 15:791. [PMID: 38927727 PMCID: PMC11203295 DOI: 10.3390/genes15060791] [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: 05/22/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Mutations in the gene SCAPER (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and intellectual disability (ID). In 2011, a possible involvement of SCAPER in human diseases was discovered for the first time due to the identification of a homozygous mutation causing ID in an Iranian family. Later, five studies were published in 2019 that described patients with autosomal recessive syndromic retinitis pigmentosa (arRP) accompanied by ID and attention-deficit/hyperactivity disorder (ADHD). This present study describes three patients from an Arab consanguineous family in Israel with similar clinical features of the SCAPER syndrome. In addition, new manifestations of ocular symptoms, nystagmus, glaucoma, and elevator palsy, were observed. Genetic testing of the patients and both parents via whole-exome sequencing revealed the homozygous mutation c.2023-2A>G in SCAPER. Phenotypic and genotypic descriptions for all available cases described in the literature including our current three cases (37 cases) were carried out, in addition to a bioinformatics analysis for all the genetic variants that was undertaken. Our study confirms and extends the clinical manifestations of SCAPER-related disorders.
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Affiliation(s)
- Rajech Sharkia
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
- Unit of Natural Sciences, Beit-Berl Academic College, Beit-Berl 4490500, Israel
| | - Abdelnaser Zalan
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
- Baqa College, Al-Qasmi Street, 64, Baqa Al-Gharbia 3010000, Israel
| | - Amit Kessel
- Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel; (A.K.); (A.A.)
| | - Wasif Al-Shareef
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
| | - Hazar Zahalka
- Child Development and Pediatric Neurology Service, Meuhedet—Northern Region, Hadera 38100, Israel;
| | - Holger Hengel
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72074 Tübingen, Germany; (H.H.); (L.S.)
- German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72074 Tübingen, Germany; (H.H.); (L.S.)
- German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel; (A.K.); (A.A.)
| | - Muhammad Mahajnah
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
- Child Neurology and Development Center, Hillel Yaffe Medical Center, Hadera 38100, Israel
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17
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Yin JZ, Keszei AFA, Houliston S, Filandr F, Beenstock J, Daou S, Kitaygorodsky J, Schriemer DC, Mazhab-Jafari MT, Gingras AC, Sicheri F. The HisRS-like domain of GCN2 is a pseudoenzyme that can bind uncharged tRNA. Structure 2024; 32:795-811.e6. [PMID: 38531363 DOI: 10.1016/j.str.2024.02.021] [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: 06/22/2023] [Revised: 01/09/2024] [Accepted: 02/28/2024] [Indexed: 03/28/2024]
Abstract
GCN2 is a stress response kinase that phosphorylates the translation initiation factor eIF2α to inhibit general protein synthesis when activated by uncharged tRNA and stalled ribosomes. The presence of a HisRS-like domain in GCN2, normally associated with tRNA aminoacylation, led to the hypothesis that eIF2α kinase activity is regulated by the direct binding of this domain to uncharged tRNA. Here we solved the structure of the HisRS-like domain in the context of full-length GCN2 by cryoEM. Structure and function analysis shows the HisRS-like domain of GCN2 has lost histidine and ATP binding but retains tRNA binding abilities. Hydrogen deuterium exchange mass spectrometry, site-directed mutagenesis and computational docking experiments support a tRNA binding model that is partially shifted from that employed by bona fide HisRS enzymes. These results demonstrate that the HisRS-like domain of GCN2 is a pseudoenzyme and advance our understanding of GCN2 regulation and function.
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Affiliation(s)
- Jay Z Yin
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alexander F A Keszei
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Scott Houliston
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada; Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Frantisek Filandr
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jonah Beenstock
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Salima Daou
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Julia Kitaygorodsky
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Mohammad T Mazhab-Jafari
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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18
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Begley M, Aragon M, Baker RW. A structure-based mechanism for initiation of AP-3 coated vesicle formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.05.597630. [PMID: 38895279 PMCID: PMC11185636 DOI: 10.1101/2024.06.05.597630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Adaptor protein complex 3 (AP-3) mediates cargo sorting from endosomes to lysosomes and lysosome-related organelles. Recently, it was shown that AP-3 is in a constitutively open, active conformation compared to the related AP-1 and AP-2 coat complexes, which are inactive until undergoing large conformational changes upon membrane recruitment. How AP-3 is regulated is therefore an open question. To understand the mechanism of AP-3 membrane recruitment and activation, we reconstituted the core of human AP-3 and determined multiple structures in the soluble and membrane-bound states using electron cryo-microscopy (cryo-EM). Similar to yeast AP-3, human AP-3 is in a constitutively open conformation, with the cargo-binding domain of the μ3 subunit conformationally free. To reconstitute AP-3 activation by the small GTPase Arf1, we used lipid nanodiscs to build Arf1-AP-3 complexes on membranes and determined three structures that show the stepwise conformational changes required for formation of AP-3 coated vesicles. First, membrane-recruitment is driven by one of two predicted Arf1 binding sites on AP-3. In this conformation, AP-3 is flexibly tethered to the membrane and its cargo binding domain remains conformationally dynamic. Second, cargo binding causes AP-3 to adopt a fixed position and rigidifies the complex, which stabilizes binding for a second Arf1 molecule. Finally, binding of the second Arf1 molecule provides the template for AP-3 dimerization, providing a glimpse into the first step of coat polymerization. We propose coat polymerization only occurs after cargo engagement, thereby linking cargo sorting with assembly of higher order coat structures. Additionally, we provide evidence for two amphipathic helices in AP-3, suggesting that AP-3 contributes to membrane deformation during coat assembly. In total, these data provide evidence for the first stages of AP-3 mediated vesicle coat assembly.
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Affiliation(s)
- Matthew Begley
- Department of Biochemistry and Biophysics, UNC Chapel Hill School of Medicine; Chapel Hill, NC 27516, USA
| | - Mahira Aragon
- New York Structural Biology Center; New York, NY 10027, USA
| | - Richard W. Baker
- Department of Biochemistry and Biophysics, UNC Chapel Hill School of Medicine; Chapel Hill, NC 27516, USA
- UNC Lineberger Comprehensive Cancer Center. UNC Chapel Hill School of Medicine; Chapel Hill, NC 27516, USA
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19
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Sung AY, Guerra RM, Steenberge LH, Alston CL, Murayama K, Okazaki Y, Shimura M, Prokisch H, Ghezzi D, Torraco A, Carrozzo R, Rötig A, Taylor RW, Keck JL, Pagliarini DJ. Systematic analysis of NDUFAF6 in complex I assembly and mitochondrial disease. Nat Metab 2024; 6:1128-1142. [PMID: 38720117 DOI: 10.1038/s42255-024-01039-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/28/2024] [Indexed: 06/27/2024]
Abstract
Isolated complex I (CI) deficiencies are a major cause of primary mitochondrial disease. A substantial proportion of CI deficiencies are believed to arise from defects in CI assembly factors (CIAFs) that are not part of the CI holoenzyme. The biochemistry of these CIAFs is poorly defined, making their role in CI assembly unclear, and confounding interpretation of potential disease-causing genetic variants. To address these challenges, we devised a deep mutational scanning approach to systematically assess the function of thousands of NDUFAF6 genetic variants. Guided by these data, biochemical analyses and cross-linking mass spectrometry, we discovered that the CIAF NDUFAF6 facilitates incorporation of NDUFS8 into CI and reveal that NDUFS8 overexpression rectifies NDUFAF6 deficiency. Our data further provide experimental support of pathogenicity for seven novel NDUFAF6 variants associated with human pathology and introduce functional evidence for over 5,000 additional variants. Overall, our work defines the molecular function of NDUFAF6 and provides a clinical resource for aiding diagnosis of NDUFAF6-related diseases.
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Affiliation(s)
- Andrew Y Sung
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Rachel M Guerra
- Department of Cell Biology and Physiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Laura H Steenberge
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Charlotte L Alston
- Mitochondrial Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, Chiba, Japan
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Yasushi Okazaki
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Masaru Shimura
- Department of Metabolism, Chiba Children's Hospital, Chiba, Japan
- Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Neuherberg, Germany
| | - Holger Prokisch
- Institute of Neurogenomics, Computational Health Center, Helmholtz Zentrum München, Neuherberg, Germany
- School of Medicine, Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Daniele Ghezzi
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Instituto Neurologico Carlo Besta, Milan, Italy
| | - Alessandra Torraco
- Unit of Cell Biology and Diagnosis of Mitochondrial Disorders, Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Rosalba Carrozzo
- Unit of Cell Biology and Diagnosis of Mitochondrial Disorders, Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Agnès Rötig
- Université Paris Cité, Imagine Institute, INSERM UMR 1163, Paris, France
| | - Robert W Taylor
- Mitochondrial Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - David J Pagliarini
- Department of Cell Biology and Physiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA.
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20
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Yee SW, Macdonald CB, Mitrovic D, Zhou X, Koleske ML, Yang J, Buitrago Silva D, Rockefeller Grimes P, Trinidad DD, More SS, Kachuri L, Witte JS, Delemotte L, Giacomini KM, Coyote-Maestas W. The full spectrum of SLC22 OCT1 mutations illuminates the bridge between drug transporter biophysics and pharmacogenomics. Mol Cell 2024; 84:1932-1947.e10. [PMID: 38703769 DOI: 10.1016/j.molcel.2024.04.008] [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: 07/11/2023] [Revised: 01/04/2024] [Accepted: 04/15/2024] [Indexed: 05/06/2024]
Abstract
Mutations in transporters can impact an individual's response to drugs and cause many diseases. Few variants in transporters have been evaluated for their functional impact. Here, we combine saturation mutagenesis and multi-phenotypic screening to dissect the impact of 11,213 missense single-amino-acid deletions, and synonymous variants across the 554 residues of OCT1, a key liver xenobiotic transporter. By quantifying in parallel expression and substrate uptake, we find that most variants exert their primary effect on protein abundance, a phenotype not commonly measured alongside function. Using our mutagenesis results combined with structure prediction and molecular dynamic simulations, we develop accurate structure-function models of the entire transport cycle, providing biophysical characterization of all known and possible human OCT1 polymorphisms. This work provides a complete functional map of OCT1 variants along with a framework for integrating functional genomics, biophysical modeling, and human genetics to predict variant effects on disease and drug efficacy.
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Affiliation(s)
- Sook Wah Yee
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Christian B Macdonald
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Darko Mitrovic
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 12121 Solna, Stockholm, Stockholm County 114 28, Sweden
| | - Xujia Zhou
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Megan L Koleske
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jia Yang
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Dina Buitrago Silva
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Patrick Rockefeller Grimes
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Donovan D Trinidad
- Department of Medicine, Division of Infectious Disease, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Swati S More
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Linda Kachuri
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University, Stanford, CA 94305, USA
| | - John S Witte
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University, Stanford, CA 94305, USA
| | - Lucie Delemotte
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 12121 Solna, Stockholm, Stockholm County 114 28, Sweden.
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Willow Coyote-Maestas
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA; Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Chan Zuckerberg Biohub, San Francisco, CA 94148, USA.
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21
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Wozny MR, Nelea V, Siddiqui IFS, Wanga S, de Waard V, Strauss M, Reinhardt DP. Microfibril-associated glycoprotein 4 forms octamers that mediate interactions with elastogenic proteins and cells. Nat Commun 2024; 15:4015. [PMID: 38740766 PMCID: PMC11091212 DOI: 10.1038/s41467-024-48377-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/29/2024] [Indexed: 05/16/2024] Open
Abstract
Microfibril-associated glycoprotein 4 (MFAP4) is a 36-kDa extracellular matrix glycoprotein with critical roles in organ fibrosis, chronic obstructive pulmonary disease, and cardiovascular disorders, including aortic aneurysms. MFAP4 multimerises and interacts with elastogenic proteins, including fibrillin-1 and tropoelastin, and with cells via integrins. Structural details of MFAP4 and its potential interfaces for these interactions are unknown. Here, we present a cryo-electron microscopy structure of human MFAP4. In the presence of calcium, MFAP4 assembles as an octamer, where two sets of homodimers constitute the top and bottom halves of each octamer. Each homodimer is linked together by an intermolecular disulphide bond. A C34S missense mutation prevents disulphide-bond formation between monomers but does not prevent octamer assembly. The atomic model, built into the 3.55 Å cryo-EM map, suggests that salt-bridge interactions mediate homodimer assembly, while non-polar residues form the interface between octamer halves. In the absence of calcium, an MFAP4 octamer dissociates into two tetramers. Binding studies with fibrillin-1, tropoelastin, LTBP4, and small fibulins show that MFAP4 has multiple surfaces for protein-protein interactions, most of which depend upon MFAP4 octamer assembly. The C34S mutation does not affect these protein interactions or cell interactions. MFAP4 assemblies with fibrillin-1 abrogate MFAP4 interactions with cells.
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Affiliation(s)
- Michael R Wozny
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Valentin Nelea
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada
| | | | - Shaynah Wanga
- Amsterdam UMC location University of Amsterdam, Medical Biochemistry, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Vivian de Waard
- Amsterdam UMC location University of Amsterdam, Medical Biochemistry, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Mike Strauss
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada.
| | - Dieter P Reinhardt
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada.
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada.
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22
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Pulsford SB, Outram MA, Förster B, Rhodes T, Williams SJ, Badger MR, Price GD, Jackson CJ, Long BM. Cyanobacterial α-carboxysome carbonic anhydrase is allosterically regulated by the Rubisco substrate RuBP. SCIENCE ADVANCES 2024; 10:eadk7283. [PMID: 38728392 PMCID: PMC11086599 DOI: 10.1126/sciadv.adk7283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 04/08/2024] [Indexed: 05/12/2024]
Abstract
Cyanobacterial CO2 concentrating mechanisms (CCMs) sequester a globally consequential proportion of carbon into the biosphere. Proteinaceous microcompartments, called carboxysomes, play a critical role in CCM function, housing two enzymes to enhance CO2 fixation: carbonic anhydrase (CA) and Rubisco. Despite its importance, our current understanding of the carboxysomal CAs found in α-cyanobacteria, CsoSCA, remains limited, particularly regarding the regulation of its activity. Here, we present a structural and biochemical study of CsoSCA from the cyanobacterium Cyanobium sp. PCC7001. Our results show that the Cyanobium CsoSCA is allosterically activated by the Rubisco substrate ribulose-1,5-bisphosphate and forms a hexameric trimer of dimers. Comprehensive phylogenetic and mutational analyses are consistent with this regulation appearing exclusively in cyanobacterial α-carboxysome CAs. These findings clarify the biologically relevant oligomeric state of α-carboxysomal CAs and advance our understanding of the regulation of photosynthesis in this globally dominant lineage.
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Affiliation(s)
- Sacha B. Pulsford
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Megan A. Outram
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Britta Förster
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Timothy Rhodes
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Simon J. Williams
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Murray R. Badger
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - G. Dean Price
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Colin J. Jackson
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Benedict M. Long
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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23
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Gogishvili D, Illes-Toth E, Harris MJ, Hopley C, Teunissen CE, Abeln S. Structural flexibility and heterogeneity of recombinant human glial fibrillary acidic protein (GFAP). Proteins 2024; 92:649-664. [PMID: 38149328 DOI: 10.1002/prot.26656] [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: 10/04/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 12/28/2023]
Abstract
Glial fibrillary acidic protein (GFAP) is a promising biomarker for brain and spinal cord disorders. Recent studies have highlighted the differences in the reliability of GFAP measurements in different biological matrices. The reason for these discrepancies is poorly understood as our knowledge of the protein's 3-dimensional conformation, proteoforms, and aggregation remains limited. Here, we investigate the structural properties of GFAP under different conditions. For this, we characterized recombinant GFAP proteins from various suppliers and applied hydrogen-deuterium exchange mass spectrometry (HDX-MS) to provide a snapshot of the conformational dynamics of GFAP in artificial cerebrospinal fluid (aCSF) compared to the phosphate buffer. Our findings indicate that recombinant GFAP exists in various conformational species. Furthermore, we show that GFAP dimers remained intact under denaturing conditions. HDX-MS experiments show an overall decrease in H-bonding and an increase in solvent accessibility of GFAP in aCSF compared to the phosphate buffer, with clear indications of mixed EX2 and EX1 kinetics. To understand possible structural interface regions and the evolutionary conservation profiles, we combined HDX-MS results with the predicted GFAP-dimer structure by AlphaFold-Multimer. We found that deprotected regions with high structural flexibility in aCSF overlap with predicted conserved dimeric 1B and 2B domain interfaces. Structural property predictions combined with the HDX data show an overall deprotection and signatures of aggregation in aCSF. We anticipate that the outcomes of this research will contribute to a deeper understanding of the structural flexibility of GFAP and ultimately shed light on its behavior in different biological matrices.
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Affiliation(s)
- Dea Gogishvili
- Bioinformatics, Computer Science Department, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- AI Technology for Life, Department of Computing and Information Sciences, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Eva Illes-Toth
- National Measurement Laboratory at Laboratory of the Government Chemist (LGC), Teddington, UK
| | - Matthew J Harris
- National Measurement Laboratory at Laboratory of the Government Chemist (LGC), Teddington, UK
| | - Christopher Hopley
- National Measurement Laboratory at Laboratory of the Government Chemist (LGC), Teddington, UK
| | - Charlotte E Teunissen
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
- Neurochemistry Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Sanne Abeln
- Bioinformatics, Computer Science Department, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- AI Technology for Life, Department of Computing and Information Sciences, Department of Biology, Utrecht University, Utrecht, The Netherlands
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24
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Benning FMC, Bell TA, Nguyen TH, Syau D, Connell LB, daCosta CJB, Chao LH. Ancestral sequence reconstruction of Mic60 reveals a residue signature supporting respiration in yeast. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591372. [PMID: 38746426 PMCID: PMC11092495 DOI: 10.1101/2024.04.26.591372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
In eukaryotes, the essential process of cellular respiration takes place in the cristae of mitochondria. The protein Mic60 is known to stabilize crista junctions; however, how the C-terminal Mitofilin domain of Mic60 mediates cristae-supported respiration remains elusive. Here, we used ancestral sequence reconstruction to generate Mitofilin ancestors up to and including the last opisthokont common ancestor (LOCA). We found that yeast-lineage derived Mitofilin ancestors as far back as the LOCA rescue respiration. By comparing Mitofilin ancestors with different respiratory phenotypes, we identify four residues that explain the difference between respiration functional yeast- and non-functional animal-derived common Mitofilin ancestors. Our results imply that Mitofilin-supported respiration in yeast stems from a conserved mechanism, and provide a foundation for investigating the divergence of candidate crista junction interactions present during the emergence of eukaryotes.
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25
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Andreas MP, Giessen TW. Cyclodipeptide oxidase is an enzyme filament. Nat Commun 2024; 15:3574. [PMID: 38678027 PMCID: PMC11055893 DOI: 10.1038/s41467-024-48030-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 04/17/2024] [Indexed: 04/29/2024] Open
Abstract
Modified cyclic dipeptides represent a widespread class of secondary metabolites with diverse pharmacological activities, including antibacterial, antifungal, and antitumor. Here, we report the structural characterization of the Streptomyces noursei enzyme AlbAB, a cyclodipeptide oxidase (CDO) carrying out α,β-dehydrogenations during the biosynthesis of the antibiotic albonoursin. We show that AlbAB is a megadalton heterooligomeric enzyme filament containing covalently bound flavin mononucleotide cofactors. We highlight that AlbAB filaments consist of alternating dimers of AlbA and AlbB and that enzyme activity is crucially dependent on filament formation. We show that AlbA-AlbB interactions are highly conserved suggesting that other CDO-like enzymes are likely enzyme filaments. As CDOs have been employed in the structural diversification of cyclic dipeptides, our results will be useful for future applications of CDOs in biocatalysis and chemoenzymatic synthesis.
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Affiliation(s)
- Michael P Andreas
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Tobias W Giessen
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
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26
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Andreas MP, Giessen TW. The biosynthesis of the odorant 2-methylisoborneol is compartmentalized inside a protein shell. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.23.590730. [PMID: 38712110 PMCID: PMC11071394 DOI: 10.1101/2024.04.23.590730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Terpenoids are the largest class of natural products, found across all domains of life. One of the most abundant bacterial terpenoids is the volatile odorant 2-methylisoborneol (2-MIB), partially responsible for the earthy smell of soil and musty taste of contaminated water. Many bacterial 2-MIB biosynthetic gene clusters were thought to encode a conserved transcription factor, named EshA in the model soil bacterium Streptomyces griseus . Here, we revise the function of EshA, now referred to as Sg Enc, and show that it is a Family 2B encapsulin shell protein. Using cryo-electron microscopy, we find that Sg Enc forms an icosahedral protein shell and encapsulates 2-methylisoborneol synthase (2-MIBS) as a cargo protein. Sg Enc contains a cyclic adenosine monophosphate (cAMP) binding domain (CBD)-fold insertion and a unique metal-binding domain, both displayed on the shell exterior. We show that Sg Enc CBDs do not bind cAMP. We find that 2-MIBS cargo loading is mediated by an N-terminal disordered cargo-loading domain and that 2-MIBS activity and Sg Enc shell structure are not modulated by cAMP. Our work redefines the function of EshA and establishes Family 2B encapsulins as cargo-loaded protein nanocompartments involved in secondary metabolite biosynthesis.
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27
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Hutchinson K, Schlessinger A. Comprehensive Characterization of LAT1 Cholesterol-Binding Sites. J Chem Theory Comput 2024; 20:3349-3358. [PMID: 38597304 DOI: 10.1021/acs.jctc.3c01391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The human L-type amino acid transporter 1 (LAT1; SLC7A5), is an amino acid exchanger protein, primarily found in the blood-brain barrier, placenta, and testis, where it plays a key role in amino acid homeostasis. Cholesterol is an essential lipid that has been highlighted to play a role in regulating the activity of membrane transporters, such as LAT1, yet little is known about the molecular mechanisms driving this phenomenon. Here we perform a comprehensive computational analysis to investigate cholesterol's role in LAT1 structure and function, focusing on four cholesterol-binding sites (CHOL1-4) identified in a recent LAT1-apo inward-open conformation cryo-EM structure. Through a series of independent molecular dynamics (MD) simulations, molecular docking, MM/GBSA free energy calculations, and other analysis tools, we explored the interactions between LAT1 and cholesterol. Our findings suggest that CHOL3 forms the most stable and favorable interactions with LAT1. Principal component analysis (PCA) and center of mass (COM) distance assessments show that CHOL3 binding stabilizes the inward-open state of LAT1 by preserving the spatial arrangement of the hash and bundle domains. Additionally, we propose an alternative cholesterol-binding site for originally assigned CHOL1. Overall, this study improves the understanding of cholesterol's modulatory effect on LAT1 and proposes candidate sites for the discovery of future allosteric ligands with rational design.
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Affiliation(s)
- Keino Hutchinson
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Department of Artificial Intelligence and Human Health, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
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28
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Martínez D, Fang L, Meza-Torres C, Garavito G, López-Lluch G, Egea E. Toward Consensus Epitopes B and T of Tropomyosin Involved in Cross-Reactivity across Diverse Allergens: An In Silico Study. Biomedicines 2024; 12:884. [PMID: 38672238 PMCID: PMC11048304 DOI: 10.3390/biomedicines12040884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 04/28/2024] Open
Abstract
Tropomyosin (TM) is a pan-allergen with cross-reactivity to arthropods, insects, and nematodes in tropical regions. While IgE epitopes of TM contribute to sensitization, T-cell (MHC-II) epitopes polarize the Th2 immune response. This study aimed to identify linear B and T consensus epitopes among house dust mites, cockroaches, Ascaris lumbricoides, shrimp, and mosquitoes, exploring the molecular basis of cross-reactivity in allergic diseases. Amino acid sequences of Der p 10, Der f 10, Blo t 10, Lit v 1, Pen a 1, Pen m 1, rAsc l 3, Per a 7, Bla g 7, and Aed a 10 were collected from Allergen Nomenclature and UniProt. B epitopes were predicted using AlgPred 2.0 and BepiPred 3.0. T epitopes were predicted with NetMHCIIpan 4.1 against 10 HLA-II alleles. Consensus epitopes were obtained through analysis and Epitope Cluster Analysis in the Immune Epitope Database. We found 7 B-cell epitopes and 28 linear T-cell epitopes binding to MHC II. A unique peptide (residues 160-174) exhibited overlap between linear B-cell and T-cell epitopes, highly conserved across tropomyosin sequences. These findings shed light on IgE cross-reactivity among the tested species. The described immuno-informatics pipeline and epitopes can inform in vitro research and guide synthetic multi-epitope proteins' design for potential allergology immunotherapies. Further in silico studies are warranted to confirm epitope accuracy and guide future experimental protocols.
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Affiliation(s)
- Dalgys Martínez
- Department of Medicine, Health Sciences Division, Universidad del Norte, Barranquilla 081007, Colombia; (D.M.); (L.F.); (C.M.-T.); (G.G.)
- Institute for Immunological Research, University of Cartagena, Cartagena 130014, Colombia
| | - Luis Fang
- Department of Medicine, Health Sciences Division, Universidad del Norte, Barranquilla 081007, Colombia; (D.M.); (L.F.); (C.M.-T.); (G.G.)
| | - Catherine Meza-Torres
- Department of Medicine, Health Sciences Division, Universidad del Norte, Barranquilla 081007, Colombia; (D.M.); (L.F.); (C.M.-T.); (G.G.)
- Department of Physiology, Anatomy, and Cellular Biology, Andalusian Centre for Development Biology (CABD-CSIC-JA), Pablo de Olavide University, 41013 Seville, Spain;
| | - Gloria Garavito
- Department of Medicine, Health Sciences Division, Universidad del Norte, Barranquilla 081007, Colombia; (D.M.); (L.F.); (C.M.-T.); (G.G.)
- Health Sciences Division, Universidad Simón Bolívar, Barranquilla 080002, Colombia
| | - Guillermo López-Lluch
- Department of Physiology, Anatomy, and Cellular Biology, Andalusian Centre for Development Biology (CABD-CSIC-JA), Pablo de Olavide University, 41013 Seville, Spain;
| | - Eduardo Egea
- Department of Medicine, Health Sciences Division, Universidad del Norte, Barranquilla 081007, Colombia; (D.M.); (L.F.); (C.M.-T.); (G.G.)
- Health Sciences Division, Universidad Simón Bolívar, Barranquilla 080002, Colombia
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29
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Karagöl A, Karagöl T, Smorodina E, Zhang S. Structural bioinformatics studies of glutamate transporters and their AlphaFold2 predicted water-soluble QTY variants and uncovering the natural mutations of L->Q, I->T, F->Y and Q->L, T->I and Y->F. PLoS One 2024; 19:e0289644. [PMID: 38598436 PMCID: PMC11006163 DOI: 10.1371/journal.pone.0289644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/22/2023] [Indexed: 04/12/2024] Open
Abstract
Glutamate transporters play key roles in nervous physiology by modulating excitatory neurotransmitter levels, when malfunctioning, involving in a wide range of neurological and physiological disorders. However, integral transmembrane proteins including the glutamate transporters remain notoriously difficult to study, due to their localization within the cell membrane. Here we present the structural bioinformatics studies of glutamate transporters and their water-soluble variants generated through QTY-code, a protein design strategy based on systematic amino acid substitutions. These include 2 structures determined by X-ray crystallography, cryo-EM, and 6 predicted by AlphaFold2, and their predicted water-soluble QTY variants. In the native structures of glutamate transporters, transmembrane helices contain hydrophobic amino acids such as leucine (L), isoleucine (I), and phenylalanine (F). To design water-soluble variants, these hydrophobic amino acids are systematically replaced by hydrophilic amino acids, namely glutamine (Q), threonine (T) and tyrosine (Y). The QTY variants exhibited water-solubility, with four having identical isoelectric focusing points (pI) and the other four having very similar pI. We present the superposed structures of the native glutamate transporters and their water-soluble QTY variants. The superposed structures displayed remarkable similarity with RMSD 0.528Å-2.456Å, despite significant protein transmembrane sequence differences (41.1%->53.8%). Additionally, we examined the differences of hydrophobicity patches between the native glutamate transporters and their QTY variants. Upon closer inspection, we discovered multiple natural variations of L->Q, I->T, F->Y and Q->L, T->I, Y->F in these transporters. Some of these natural variations were benign and the remaining were reported in specific neurological disorders. We further investigated the characteristics of hydrophobic to hydrophilic substitutions in glutamate transporters, utilizing variant analysis and evolutionary profiling. Our structural bioinformatics studies not only provided insight into the differences between the hydrophobic helices and hydrophilic helices in the glutamate transporters, but they are also expected to stimulate further study of other water-soluble transmembrane proteins.
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Affiliation(s)
- Alper Karagöl
- Istanbul University Istanbul Medical Faculty, Istanbul, Turkey
| | - Taner Karagöl
- Istanbul University Istanbul Medical Faculty, Istanbul, Turkey
| | - Eva Smorodina
- Laboratory for Computational and Systems Immunology, Department of Immunology, University of Oslo, Oslo University Hospital, Oslo, Norway
| | - Shuguang Zhang
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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30
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Knejski PP, Erramilli SK, Kossiakoff AA. Chaperone-assisted cryo-EM structure of P. aeruginosa PhuR reveals molecular basis for heme binding. Structure 2024; 32:411-423.e6. [PMID: 38325368 PMCID: PMC10997469 DOI: 10.1016/j.str.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/14/2023] [Accepted: 01/11/2024] [Indexed: 02/09/2024]
Abstract
Pathogenic bacteria, such as Pseudomonas aeruginosa, depend on scavenging heme for the acquisition of iron, an essential nutrient. The TonB-dependent transporter (TBDT) PhuR is the major heme uptake protein in P. aeruginosa clinical isolates. However, a comprehensive understanding of heme recognition and TBDT transport mechanisms, especially PhuR, remains limited. In this study, we employed single-particle cryogenic electron microscopy (cryo-EM) and a phage display-generated synthetic antibody (sAB) as a fiducial marker to enable the determination of a high-resolution (2.5 Å) structure of PhuR with a bound heme. Notably, the structure reveals iron coordination by Y529 on a conserved extracellular loop, shedding light on the role of tyrosine in heme binding. Biochemical assays and negative-stain EM demonstrated that the sAB specifically targets the heme-bound state of PhuR. These findings provide insights into PhuR's heme binding and offer a template for developing conformation-specific sABs against outer membrane proteins (OMPs) for structure-function investigations.
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Affiliation(s)
- Paweł P Knejski
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA.
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
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31
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Mukhopadhyay AG, Toropova K, Daly L, Wells JN, Vuolo L, Mladenov M, Seda M, Jenkins D, Stephens DJ, Roberts AJ. Structure and tethering mechanism of dynein-2 intermediate chains in intraflagellar transport. EMBO J 2024; 43:1257-1272. [PMID: 38454149 PMCID: PMC10987677 DOI: 10.1038/s44318-024-00060-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 03/09/2024] Open
Abstract
Dynein-2 is a large multiprotein complex that powers retrograde intraflagellar transport (IFT) of cargoes within cilia/flagella, but the molecular mechanism underlying this function is still emerging. Distinctively, dynein-2 contains two identical force-generating heavy chains that interact with two different intermediate chains (WDR34 and WDR60). Here, we dissect regulation of dynein-2 function by WDR34 and WDR60 using an integrative approach including cryo-electron microscopy and CRISPR/Cas9-enabled cell biology. A 3.9 Å resolution structure shows how WDR34 and WDR60 use surprisingly different interactions to engage equivalent sites of the two heavy chains. We show that cilia can assemble in the absence of either WDR34 or WDR60 individually, but not both subunits. Dynein-2-dependent distribution of cargoes depends more strongly on WDR60, because the unique N-terminal extension of WDR60 facilitates dynein-2 targeting to cilia. Strikingly, this N-terminal extension can be transplanted onto WDR34 and retain function, suggesting it acts as a flexible tether to the IFT "trains" that assemble at the ciliary base. We discuss how use of unstructured tethers represents an emerging theme in IFT train interactions.
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Affiliation(s)
- Aakash G Mukhopadhyay
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Katerina Toropova
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Lydia Daly
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
- Randall Centre of Cell & Molecular Biophysics, King's College London, London, UK
| | - Jennifer N Wells
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
- MRC London Institute of Medical Sciences (LMS), London, UK
| | - Laura Vuolo
- Cell Biology Laboratories, School of Biochemistry, University of Bristol, Bristol, UK
| | - Miroslav Mladenov
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, London, UK
| | - Marian Seda
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Dagan Jenkins
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, University of Bristol, Bristol, UK
| | - Anthony J Roberts
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK.
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32
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Hwang J, Lee MJ, Lee SG, Do H, Lee JH. Structural insights into the distinct substrate preferences of two bacterial epoxide hydrolases. Int J Biol Macromol 2024; 264:130419. [PMID: 38423431 DOI: 10.1016/j.ijbiomac.2024.130419] [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: 11/20/2023] [Revised: 01/22/2024] [Accepted: 02/22/2024] [Indexed: 03/02/2024]
Abstract
Epoxide hydrolases (EHs), which catalyze the transformation of epoxides to diols, are present in many eukaryotic and prokaryotic organisms. They have recently drawn considerable attention from organic chemists owing to their application in the semisynthesis of enantiospecific diol compounds. Here, we report the crystal structures of BoEH from Bosea sp. PAMC 26642 and CaEH from Caballeronia sordidicola PAMC 26510 at 1.95 and 2.43 Å resolution, respectively. Structural analysis showed that the overall structures of BoEH and CaEH commonly possess typical α/β hydrolase fold with the same ring-opening residues (Tyr-Tyr) and conserved catalytic triad residues (Asp-Asp-His). However, the two enzymes were found to have significantly different sequence compositions in the cap domain region, which is involved in the formation of the substrate-binding site in both enzymes. Enzyme activity assay results showed that BoEH had the strongest activity toward the linear aliphatic substrates, whereas CaEH had a higher preference for aromatic- and cycloaliphatic substrates. Computational docking simulations and tunnel identification revealed important residues with different substrate-binding preferences. Collectively, structure comparison studies, together with ligand docking simulation results, suggested that the differences in substrate-binding site residues were highly correlated with substrate specificity.
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Affiliation(s)
- Jisub Hwang
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Min Ju Lee
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Sung Gu Lee
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Hackwon Do
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea.
| | - Jun Hyuck Lee
- Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea.
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33
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Failayev H, Ganoth A, Tsfadia Y. Molecular insights on the coronavirus MERS-CoV interaction with the CD26 receptor. Virus Res 2024; 342:199330. [PMID: 38272241 PMCID: PMC10862065 DOI: 10.1016/j.virusres.2024.199330] [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: 08/29/2023] [Revised: 12/21/2023] [Accepted: 01/22/2024] [Indexed: 01/27/2024]
Abstract
The Middle East respiratory syndrome (MERS) is a severe respiratory disease with high fatality rates, caused by the Middle East respiratory syndrome coronavirus (MERS-CoV). The virus initiates infection by binding to the CD26 receptor (also known as dipeptidyl peptidase 4 or DPP4) via its spike protein. Although the receptor-binding domain (RBD) of the viral spike protein and the complex between RBD and the extracellular domain of CD26 have been studied using X-ray crystallography, conflicting studies exist regarding the importance of certain amino acids outside the resolved RBD-CD26 complex interaction interface. To gain atomic-level knowledge of the RBD-CD26 complex, we employed computational simulations to study the complex's dynamic behavior as it evolves from its crystal structure to a conformation stable in solution. Our study revealed previously unidentified interaction regions and interacting amino acids within the complex, determined a novel comprehensive RBD-binding domain of CD26, and by that expanded the current understanding of its structure. Additionally, we examined the impact of a single amino acid substitution, E513A, on the complex's stability. We discovered that this substitution disrupts the complex through an allosteric domino-like mechanism that affects other residues. Since MERS-CoV is a zoonotic virus, we evaluated its potential risk of human infection via animals, and suggest a low likelihood for possible infection by cats or dogs. The molecular structural information gleaned from our insights into the RBD-CD26 complex pre-dissociative states may be proved useful not only from a mechanistic view but also in assessing inter-species transmission and in developing anti-MERS-CoV antiviral therapeutics.
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Affiliation(s)
- Hila Failayev
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Assaf Ganoth
- Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; The Interdisciplinary Center (IDC), P.O. Box 167, Herzliya 4610101, Israel
| | - Yossi Tsfadia
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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34
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Pierdominici‐Sottile G, Palma J, Ferrelli ML, Sobrado P. The dynamics of the flavin, NADPH, and active site loops determine the mechanism of activation of class B flavin-dependent monooxygenases. Protein Sci 2024; 33:e4935. [PMID: 38501462 PMCID: PMC10962481 DOI: 10.1002/pro.4935] [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: 10/11/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 03/20/2024]
Abstract
Flavin-dependent monooxygenases (FMOs) constitute a diverse enzyme family that catalyzes crucial hydroxylation, epoxidation, and Baeyer-Villiger reactions across various metabolic pathways in all domains of life. Due to the intricate nature of this enzyme family's mechanisms, some aspects of their functioning remain unknown. Here, we present the results of molecular dynamics computations, supplemented by a bioinformatics analysis, that clarify the early stages of their catalytic cycle. We have elucidated the intricate binding mechanism of NADPH and L-Orn to a class B monooxygenase, the ornithine hydroxylase fromAspergillus $$ Aspergillus $$ fumigatus $$ fumigatus $$ known as SidA. Our investigation involved a comprehensive characterization of the conformational changes associated with the FAD (Flavin Adenine Dinucleotide) cofactor, transitioning from the out to the in position. Furthermore, we explored the rotational dynamics of the nicotinamide ring of NADPH, shedding light on its role in facilitating FAD reduction, supported by experimental evidence. Finally, we also analyzed the extent of conservation of two Tyr-loops that play critical roles in the process.
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Affiliation(s)
- Gustavo Pierdominici‐Sottile
- Departamento de Ciencia y TecnologíaUniversidad Nacional de QuilmesBernalArgentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
| | - Juliana Palma
- Departamento de Ciencia y TecnologíaUniversidad Nacional de QuilmesBernalArgentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
| | - María Leticia Ferrelli
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
- Instituto de Biotecnología y Biología Molecular (IBBM, UNLP‐CONICET), Facultad de Ciencias ExactasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Pablo Sobrado
- Department of BiochemistryVirginia TechBlacksburgVirginiaUSA
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35
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Singh K, Lau CK, Manigrasso G, Gama JB, Gassmann R, Carter AP. Molecular mechanism of dynein-dynactin complex assembly by LIS1. Science 2024; 383:eadk8544. [PMID: 38547289 PMCID: PMC7615804 DOI: 10.1126/science.adk8544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 02/09/2024] [Indexed: 04/02/2024]
Abstract
Cytoplasmic dynein is a microtubule motor vital for cellular organization and division. It functions as a ~4-megadalton complex containing its cofactor dynactin and a cargo-specific coiled-coil adaptor. However, how dynein and dynactin recognize diverse adaptors, how they interact with each other during complex formation, and the role of critical regulators such as lissencephaly-1 (LIS1) protein (LIS1) remain unclear. In this study, we determined the cryo-electron microscopy structure of dynein-dynactin on microtubules with LIS1 and the lysosomal adaptor JIP3. This structure reveals the molecular basis of interactions occurring during dynein activation. We show how JIP3 activates dynein despite its atypical architecture. Unexpectedly, LIS1 binds dynactin's p150 subunit, tethering it along the length of dynein. Our data suggest that LIS1 and p150 constrain dynein-dynactin to ensure efficient complex formation.
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Affiliation(s)
- Kashish Singh
- MRC Laboratory of Molecular Biology, Francis Crick Ave, Cambridge, CB2 0QH, UK
| | - Clinton K. Lau
- MRC Laboratory of Molecular Biology, Francis Crick Ave, Cambridge, CB2 0QH, UK
| | - Giulia Manigrasso
- MRC Laboratory of Molecular Biology, Francis Crick Ave, Cambridge, CB2 0QH, UK
| | - José B. Gama
- Instituto de Investigação e Inovação em Saúde – i3S / Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, 4200-135 Porto, Portugal
| | - Reto Gassmann
- Instituto de Investigação e Inovação em Saúde – i3S / Instituto de Biologia Molecular e Celular – IBMC, Universidade do Porto, 4200-135 Porto, Portugal
| | - Andrew P. Carter
- MRC Laboratory of Molecular Biology, Francis Crick Ave, Cambridge, CB2 0QH, UK
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36
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Yang C, Sun X, Wu G. New insights into GATOR2-dependent interactions and its conformational changes in amino acid sensing. Biosci Rep 2024; 44:BSR20240038. [PMID: 38372438 PMCID: PMC10938194 DOI: 10.1042/bsr20240038] [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: 02/01/2024] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 02/20/2024] Open
Abstract
Eukaryotic cells coordinate growth under different environmental conditions via mechanistic target of rapamycin complex 1 (mTORC1). In the amino-acid-sensing signalling pathway, the GATOR2 complex, containing five evolutionarily conserved subunits (WDR59, Mios, WDR24, Seh1L and Sec13), is required to regulate mTORC1 activity by interacting with upstream CASTOR1 (arginine sensor) and Sestrin2 (leucine sensor and downstream GATOR1 complex). GATOR2 complex utilizes β-propellers to engage with CASTOR1, Sestrin2 and GATOR1, removal of these β-propellers results in substantial loss of mTORC1 capacity. However, structural information regarding the interface between amino acid sensors and GATOR2 remains elusive. With the recent progress of the AI-based tool AlphaFold2 (AF2) for protein structure prediction, structural models were predicted for Sentrin2-WDR24-Seh1L and CASTOR1-Mios β-propeller. Furthermore, the effectiveness of relevant residues within the interface was examined using biochemical experiments combined with molecular dynamics (MD) simulations. Notably, fluorescence resonance energy transfer (FRET) analysis detected the structural transition of GATOR2 in response to amino acid signals, and the deletion of Mios β-propeller severely impeded that change at distinct arginine levels. These findings provide structural perspectives on the association between GATOR2 and amino acid sensors and can facilitate future research on structure determination and function.
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Affiliation(s)
- Can Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, the Joint International Research Laboratory of Metabolic and Developmental Sciences MOE, Shanghai Jiao Tong University, Shanghai, China
| | - Xuan Sun
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, the Joint International Research Laboratory of Metabolic and Developmental Sciences MOE, Shanghai Jiao Tong University, Shanghai, China
| | - Geng Wu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, the Joint International Research Laboratory of Metabolic and Developmental Sciences MOE, Shanghai Jiao Tong University, Shanghai, China
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37
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Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here, we report a 3.1 Å resolution cryo-electron microscopy (cryo-EM) structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
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Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of PittsburghPittsburghUnited States
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook UniversityStony BrookUnited States
| | - Jonathan A Coleman
- Department of Structural Biology, University of PittsburghPittsburghUnited States
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38
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Jones JA, Andreas MP, Giessen TW. Structural basis for peroxidase encapsulation inside the encapsulin from the Gram-negative pathogen Klebsiella pneumoniae. Nat Commun 2024; 15:2558. [PMID: 38519509 PMCID: PMC10960027 DOI: 10.1038/s41467-024-46880-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
Encapsulins are self-assembling protein nanocompartments capable of selectively encapsulating dedicated cargo proteins, including enzymes involved in iron storage, sulfur metabolism, and stress resistance. They represent a unique compartmentalization strategy used by many pathogens to facilitate specialized metabolic capabilities. Encapsulation is mediated by specific cargo protein motifs known as targeting peptides (TPs), though the structural basis for encapsulation of the largest encapsulin cargo class, dye-decolorizing peroxidases (DyPs), is currently unknown. Here, we characterize a DyP-containing encapsulin from the enterobacterial pathogen Klebsiella pneumoniae. By combining cryo-electron microscopy with TP and TP-binding site mutagenesis, we elucidate the molecular basis for cargo encapsulation. TP binding is mediated by cooperative hydrophobic and ionic interactions as well as shape complementarity. Our results expand the molecular understanding of enzyme encapsulation inside protein nanocompartments and lay the foundation for rationally modulating encapsulin cargo loading for biomedical and biotechnological applications.
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Affiliation(s)
- Jesse A Jones
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Michael P Andreas
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Tobias W Giessen
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.
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39
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Zoch A, Konieczny G, Auchynnikava T, Stallmeyer B, Rotte N, Heep M, Berrens RV, Schito M, Kabayama Y, Schöpp T, Kliesch S, Houston B, Nagirnaja L, O'Bryan MK, Aston KI, Conrad DF, Rappsilber J, Allshire RC, Cook AG, Tüttelmann F, O'Carroll D. C19ORF84 connects piRNA and DNA methylation machineries to defend the mammalian germ line. Mol Cell 2024; 84:1021-1035.e11. [PMID: 38359823 PMCID: PMC10960678 DOI: 10.1016/j.molcel.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/01/2023] [Accepted: 01/17/2024] [Indexed: 02/17/2024]
Abstract
In the male mouse germ line, PIWI-interacting RNAs (piRNAs), bound by the PIWI protein MIWI2 (PIWIL4), guide DNA methylation of young active transposons through SPOCD1. However, the underlying mechanisms of SPOCD1-mediated piRNA-directed transposon methylation and whether this pathway functions to protect the human germ line remain unknown. We identified loss-of-function variants in human SPOCD1 that cause defective transposon silencing and male infertility. Through the analysis of these pathogenic alleles, we discovered that the uncharacterized protein C19ORF84 interacts with SPOCD1. DNMT3C, the DNA methyltransferase responsible for transposon methylation, associates with SPOCD1 and C19ORF84 in fetal gonocytes. Furthermore, C19ORF84 is essential for piRNA-directed DNA methylation and male mouse fertility. Finally, C19ORF84 mediates the in vivo association of SPOCD1 with the de novo methylation machinery. In summary, we have discovered a conserved role for the human piRNA pathway in transposon silencing and C19ORF84, an uncharacterized protein essential for orchestrating piRNA-directed DNA methylation.
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Affiliation(s)
- Ansgar Zoch
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK.
| | - Gabriela Konieczny
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Tania Auchynnikava
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Birgit Stallmeyer
- Institute of Reproductive Genetics, University of Münster, Münster, Germany
| | - Nadja Rotte
- Institute of Reproductive Genetics, University of Münster, Münster, Germany
| | - Madeleine Heep
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Rebecca V Berrens
- Institute for Developmental and Regenerative Medicine, University of Oxford, IMS-Tetsuya Nakamura Building, Old Road Campus, Roosevelt Drive, Oxford OX37TY, UK
| | - Martina Schito
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Yuka Kabayama
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Theresa Schöpp
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Sabine Kliesch
- Centre of Reproductive Medicine and Andrology, Department of Clinical and Surgical Andrology, University Hospital Münster, Münster, Germany
| | - Brendan Houston
- School of BioSciences and Bio21 Institute, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Liina Nagirnaja
- Division of Genetics, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Moira K O'Bryan
- School of BioSciences and Bio21 Institute, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Kenneth I Aston
- Andrology and In Vitro Fertilization Laboratory, Department of Surgery (Urology), University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Donald F Conrad
- Division of Genetics, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA; Center for Embryonic Cell and Gene Therapy, Oregon Health and Science University, Portland, OR, USA
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK; Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Robin C Allshire
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Atlanta G Cook
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Frank Tüttelmann
- Institute of Reproductive Genetics, University of Münster, Münster, Germany
| | - Dónal O'Carroll
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute for Stem Cell Research, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK; Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK.
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40
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Alpsoy A, Wu XS, Pal S, Klingbeil O, Kumar P, El Demerdash O, Nalbant B, Vakoc CR. IκBζ is a dual-use coactivator of NF-κB and POU transcription factors. Mol Cell 2024; 84:1149-1157.e7. [PMID: 38309274 PMCID: PMC10960667 DOI: 10.1016/j.molcel.2024.01.007] [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: 07/28/2023] [Revised: 12/01/2023] [Accepted: 01/09/2024] [Indexed: 02/05/2024]
Abstract
OCA-B, OCA-T1, and OCA-T2 belong to a family of coactivators that bind to POU transcription factors (TFs) to regulate gene expression in immune cells. Here, we identify IκBζ (encoded by the NFKBIZ gene) as an additional coactivator of POU TFs. Although originally discovered as an inducible regulator of NF-κB, we show here that IκBζ shares a microhomology with OCA proteins and uses this segment to bind to POU TFs and octamer-motif-containing DNA. Our functional experiments suggest that IκBζ requires its interaction with POU TFs to coactivate immune-related genes. This finding is reinforced by epigenomic analysis of MYD88L265P-mutant lymphoma cells, which revealed colocalization of IκBζ with the POU TF OCT2 and NF-κB:p50 at hundreds of DNA elements harboring octamer and κB motifs. These results suggest that IκBζ is a transcriptional coactivator that can amplify and integrate the output of NF-κB and POU TFs at inducible genes in immune cells.
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Affiliation(s)
- Aktan Alpsoy
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Xiaoli S Wu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Sujay Pal
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Olaf Klingbeil
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Pramod Kumar
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Benan Nalbant
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
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41
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Muthukumar G, Stevens TA, Inglis AJ, Esantsi TK, Saunders RA, Schulte F, Voorhees RM, Guna A, Weissman JS. Triaging of α-helical proteins to the mitochondrial outer membrane by distinct chaperone machinery based on substrate topology. Mol Cell 2024; 84:1101-1119.e9. [PMID: 38428433 DOI: 10.1016/j.molcel.2024.01.028] [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: 07/31/2023] [Revised: 12/08/2023] [Accepted: 01/31/2024] [Indexed: 03/03/2024]
Abstract
Mitochondrial outer membrane ⍺-helical proteins play critical roles in mitochondrial-cytoplasmic communication, but the rules governing the targeting and insertion of these biophysically diverse proteins remain unknown. Here, we first defined the complement of required mammalian biogenesis machinery through genome-wide CRISPRi screens using topologically distinct membrane proteins. Systematic analysis of nine identified factors across 21 diverse ⍺-helical substrates reveals that these components are organized into distinct targeting pathways that act on substrates based on their topology. NAC is required for the efficient targeting of polytopic proteins, whereas signal-anchored proteins require TTC1, a cytosolic chaperone that physically engages substrates. Biochemical and mutational studies reveal that TTC1 employs a conserved TPR domain and a hydrophobic groove in its C-terminal domain to support substrate solubilization and insertion into mitochondria. Thus, the targeting of diverse mitochondrial membrane proteins is achieved through topological triaging in the cytosol using principles with similarities to ER membrane protein biogenesis systems.
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Affiliation(s)
- Gayathri Muthukumar
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Taylor A Stevens
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Avenue, Pasadena, CA 91125, USA
| | - Alison J Inglis
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Avenue, Pasadena, CA 91125, USA
| | - Theodore K Esantsi
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Reuben A Saunders
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Fabian Schulte
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Rebecca M Voorhees
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Avenue, Pasadena, CA 91125, USA
| | - Alina Guna
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Avenue, Pasadena, CA 91125, USA.
| | - Jonathan S Weissman
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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42
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Balakrishnan S, Adolph M, Tsai MS, Akizuki T, Gallagher K, Cortez D, Chazin WJ. Structure of RADX and mechanism for regulation of RAD51 nucleofilaments. Proc Natl Acad Sci U S A 2024; 121:e2316491121. [PMID: 38466836 PMCID: PMC10962997 DOI: 10.1073/pnas.2316491121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024] Open
Abstract
Replication fork reversal is a fundamental process required for resolution of encounters with DNA damage. A key step in the stabilization and eventual resolution of reversed forks is formation of RAD51 nucleoprotein filaments on exposed single strand DNA (ssDNA). To avoid genome instability, RAD51 filaments are tightly controlled by a variety of positive and negative regulators. RADX (RPA-related RAD51-antagonist on the X chromosome) is a recently discovered negative regulator that binds tightly to ssDNA, directly interacts with RAD51, and regulates replication fork reversal and stabilization in a context-dependent manner. Here, we present a structure-based investigation of RADX's mechanism of action. Mass photometry experiments showed that RADX forms multiple oligomeric states in a concentration-dependent manner, with a predominance of trimers in the presence of ssDNA. The structure of RADX, which has no structurally characterized orthologs, was determined ab initio by cryo-electron microscopy (cryo-EM) from maps in the 2 to 4 Å range. The structure reveals the molecular basis for RADX oligomerization and the coupled multi-valent binding of ssDNA binding. The interaction of RADX with RAD51 filaments was imaged by negative stain EM, which showed a RADX oligomer at the end of filaments. Based on these results, we propose a model in which RADX functions by capping and restricting the end of RAD51 filaments.
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Affiliation(s)
- Swati Balakrishnan
- Center for Structural Biology, Vanderbilt University, Nashville, TN37240
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
| | - Madison Adolph
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
| | - Miaw-Sheue Tsai
- Biological Systems and Bioengineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Tae Akizuki
- Center for Structural Biology, Vanderbilt University, Nashville, TN37240
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
| | - Kaitlyn Gallagher
- Center for Structural Biology, Vanderbilt University, Nashville, TN37240
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
| | - David Cortez
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
| | - Walter J. Chazin
- Center for Structural Biology, Vanderbilt University, Nashville, TN37240
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN37237
- Department of Chemistry, Vanderbilt University, Nashville, TN37235
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43
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Li J, Kang X, Guidi I, Lu L, Fernández-Millán P, Prats-Ejarque G, Boix E. Structural determinants for tRNA selective cleavage by RNase 2/EDN. Structure 2024; 32:328-341.e4. [PMID: 38228145 DOI: 10.1016/j.str.2023.12.012] [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: 08/22/2023] [Revised: 11/03/2023] [Accepted: 12/20/2023] [Indexed: 01/18/2024]
Abstract
tRNA-derived fragments (tRFs) have emerged as key players of immunoregulation. Some RNase A superfamily members participate in the shaping of the tRFs population. By comparing wild-type and knockout macrophage cell lines, our previous work revealed that RNase 2 can selectively cleave tRNAs. Here, we confirm the in vitro protein cleavage pattern by screening of synthetic tRNAs, single-mutant variants, and anticodon-loop DNA/RNA hairpins. By sequencing of tRF products, we identified the cleavage selectivity of recombinant RNase 2 with base specificity at B1 (U/C) and B2 (A) sites, consistent with a previous cellular study. Lastly, protein-hairpin complexes were predicted by MD simulations. Results reveal the contribution of the α1, loop 3 and loop 4, and β6 RNase 2 regions, where residues Arg36/Asn39/Gln40/Asn65/Arg68/Arg132 provide interactions, spanning from P-1 to P2 sites that are essential for anticodon loop recognition. Knowledge of RNase 2-specific tRFs generation might guide new therapeutic approaches for infectious and immune-related diseases.
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Affiliation(s)
- Jiarui Li
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain.
| | - Xincheng Kang
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Irene Guidi
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Lu Lu
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Pablo Fernández-Millán
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Guillem Prats-Ejarque
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Ester Boix
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, 08193 Barcelona, Spain.
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44
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Penner TV, Lorente Cobo N, Patel DT, Patel DH, Savchenko A, Brassinga AKC, Prehna G. Structural characterization of the Sel1-like repeat protein LceB from Legionella pneumophila. Protein Sci 2024; 33:e4889. [PMID: 38160319 PMCID: PMC10868440 DOI: 10.1002/pro.4889] [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: 07/03/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 01/03/2024]
Abstract
Legionella are freshwater Gram-negative bacteria that in their normal environment infect protozoa. However, this adaptation also allows Legionella to infect human alveolar macrophages and cause pneumonia. Central to Legionella pathogenesis are more than 330 secreted effectors, of which there are nine core effectors that are conserved in all pathogenic species. Despite their importance, the biochemical function of several core effectors remains unclear. To address this, we have taken a structural approach to characterize the core effector of unknown function LceB, or Lpg1356, from Legionella pneumophila. Here, we solve an X-ray crystal structure of LceB using an AlphaFold model for molecular replacement. The experimental structure shows that LceB adopts a Sel1-like repeat (SLR) fold as predicted. However, the crystal structure captured multiple conformations of LceB, all of which differed from the AlphaFold model. A comparison of the predicted model and the experimental models suggests that LceB is highly flexible in solution. Additionally, the molecular analysis of LceB using its close structural homologs reveals sequence and structural motifs of known biochemical function. Specifically, LceB harbors a repeated KAAEQG motif that both stabilizes the SLR fold and is known to participate in protein-protein interactions with eukaryotic host proteins. We also observe that LceB forms several higher-order oligomers in solution. Overall, our results have revealed that LceB has conformational flexibility, self-associates, and contains a molecular surface for binding a target host-cell protein. Additionally, our data provides structural insights into the SLR family of proteins that remain poorly studied.
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Affiliation(s)
- Tiffany V Penner
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Neil Lorente Cobo
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Deepak T Patel
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Dhruvin H Patel
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Alexei Savchenko
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | | | - Gerd Prehna
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
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45
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Vincenzi M, Mercurio FA, Autiero I, Leone M. Cancer-Related Mutations in the Sam Domains of EphA2 Receptor and Ship2 Lipid Phosphatase: A Computational Study. Molecules 2024; 29:1024. [PMID: 38474536 DOI: 10.3390/molecules29051024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/09/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
The lipid phosphatase Ship2 interacts with the EphA2 receptor by forming a heterotypic Sam (sterile alpha motif)-Sam complex. Ship2 works as a negative regulator of receptor endocytosis and consequent degradation, and anti-oncogenic effects in cancer cells should be induced by hindering its association with EphA2. Herein, a computational approach is presented to investigate the relationship between Ship2-Sam/EphA2-Sam interaction and cancer onset and further progression. A search was first conducted through the COSMIC (Catalogue of Somatic Mutations in Cancer) database to identify cancer-related missense mutations positioned inside or close to the EphA2-Sam and Ship2-Sam reciprocal binding interfaces. Next, potential differences in the chemical-physical properties of mutant and wild-type Sam domains were evaluated by bioinformatics tools based on analyses of primary sequences. Three-dimensional (3D) structural models of mutated EphA2-Sam and Ship2-Sam domains were built as well and deeply analysed with diverse computational instruments, including molecular dynamics, to classify potentially stabilizing and destabilizing mutations. In the end, the influence of mutations on the EphA2-Sam/Ship2-Sam interaction was studied through docking techniques. This in silico approach contributes to understanding, at the molecular level, the mutation/cancer relationship by predicting if amino acid substitutions could modulate EphA2 receptor endocytosis.
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Affiliation(s)
- Marian Vincenzi
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Flavia Anna Mercurio
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Ida Autiero
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
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46
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Rivera K, Tanaka KJ, Buechel ER, Origel O, Harrison A, Mason KM, Pinkett HW. Antimicrobial Peptide Recognition Motif of the Substrate Binding Protein SapA from Nontypeable Haemophilus influenzae. Biochemistry 2024; 63:294-311. [PMID: 38189237 PMCID: PMC10851439 DOI: 10.1021/acs.biochem.3c00562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 01/09/2024]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen associated with respiratory diseases, including otitis media and exacerbations of chronic obstructive pulmonary disease. NTHi exhibits resistance to killing by host antimicrobial peptides (AMPs) mediated by SapA, the substrate binding protein of the sensitivity to antimicrobial peptides (Sap) transporter. However, the specific mechanisms by which SapA selectively binds various AMPs such as defensins and cathelicidin are unknown. In this study, we report mutational analyses of both defensin AMPs and the SapA binding pocket to define the specificity of AMP recognition. Bactericidal assays revealed that NTHi lacking SapA are more susceptible to human beta defensins and LL-37, while remaining highly resistant to a human alpha defensin. In contrast to homologues, our research underscores the distinct specificity of NTHi SapA, which selectively recognizes and binds to peptides containing the charged-hydrophobic motif PKE and RRY. These findings provide valuable insight into the divergence of SapA among bacterial species and NTHi SapA's ability to selectively interact with specific AMPs to mediate resistance.
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Affiliation(s)
- Kristen
G. Rivera
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Kari J. Tanaka
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Evan R. Buechel
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Octavio Origel
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Alistair Harrison
- The
Center for Microbial Pathogenesis, The Abigail Wexner Research Institute
at Nationwide Children’s Hospital and College of Medicine,
Department of Pediatrics, The Ohio State
University, Columbus, Ohio 43205, United States
| | - Kevin M. Mason
- The
Center for Microbial Pathogenesis, The Abigail Wexner Research Institute
at Nationwide Children’s Hospital and College of Medicine,
Department of Pediatrics, The Ohio State
University, Columbus, Ohio 43205, United States
| | - Heather W. Pinkett
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
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47
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Benisch R, Andreas MP, Giessen TW. A widespread bacterial protein compartment sequesters and stores elemental sulfur. SCIENCE ADVANCES 2024; 10:eadk9345. [PMID: 38306423 PMCID: PMC10836720 DOI: 10.1126/sciadv.adk9345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/03/2024] [Indexed: 02/04/2024]
Abstract
Subcellular compartments often serve to store nutrients or sequester labile or toxic compounds. As bacteria mostly do not possess membrane-bound organelles, they often have to rely on protein-based compartments. Encapsulins are one of the most prevalent protein-based compartmentalization strategies found in prokaryotes. Here, we show that desulfurase encapsulins can sequester and store large amounts of crystalline elemental sulfur. We determine the 1.78-angstrom cryo-EM structure of a 24-nanometer desulfurase-loaded encapsulin. Elemental sulfur crystals can be formed inside the encapsulin shell in a desulfurase-dependent manner with l-cysteine as the sulfur donor. Sulfur accumulation can be influenced by the concentration and type of sulfur source in growth medium. The selectively permeable protein shell allows the storage of redox-labile elemental sulfur by excluding cellular reducing agents, while encapsulation substantially improves desulfurase activity and stability. These findings represent an example of a protein compartment able to accumulate and store elemental sulfur.
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Affiliation(s)
- Robert Benisch
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael P. Andreas
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Tobias W. Giessen
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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48
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Zecchin P, Pecqueur L, Oltmanns J, Velours C, Schünemann V, Fontecave M, Golinelli‐Pimpaneau B. Structure-based insights into the mechanism of [4Fe-4S]-dependent sulfur insertase LarE. Protein Sci 2024; 33:e4874. [PMID: 38100250 PMCID: PMC10806937 DOI: 10.1002/pro.4874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/28/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
Several essential cellular metabolites, such as enzyme cofactors, contain sulfur atoms and their biosynthesis requires specific thiolation enzymes. LarE is an ATP-dependent sulfur insertase, which catalyzes the sequential conversion of the two carboxylate groups of the precursor of the lactate racemase cofactor into thiocarboxylates. Two types of LarE enzymes are known, one that uses a catalytic cysteine as a sacrificial sulfur donor, and the other one that uses a [4Fe-4S] cluster as a cofactor. Only the crystal structure of LarE from Lactobacillus plantarum (LpLarE) from the first class has been solved. We report here the crystal structure of LarE from Methanococcus maripaludis (MmLarE), belonging to the second class, in the cluster-free (apo-) and cluster-bound (holo-) forms. The structure of holo-MmLarE shows that the [4Fe-4S] cluster is chelated by three cysteines only, leaving an open coordination site on one Fe atom. Moreover, the fourth nonprotein-bonded iron atom was able to bind an anionic ligand such as a phosphate group or a chloride ion. Together with the spectroscopic analysis of holo-MmLarE and the previously reported biochemical investigations of holo-LarE from Thermotoga maritima, these crystal structures support the hypothesis of a reaction mechanism, in which the [4Fe-4S] cluster binds a hydrogenosulfide ligand in place of the chloride anion, thus generating a [4Fe-5S] intermediate, and transfers it to the substrate, as in the case of [4Fe-4S]-dependent tRNA thiolation enzymes.
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Affiliation(s)
- Paolo Zecchin
- Laboratoire de Chimie des Processus Biologiques, Collège de France, CNRS UMR 8829Sorbonne UniversitéParis cedex 05France
| | - Ludovic Pecqueur
- Laboratoire de Chimie des Processus Biologiques, Collège de France, CNRS UMR 8829Sorbonne UniversitéParis cedex 05France
| | - Jonathan Oltmanns
- Universität of Kaiserslautern‐LandauDepartment of PhysicsKaiserslauternGermany
| | - Christophe Velours
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRSUniversité Paris‐SaclayGif‐sur‐Yvette cedexFrance
- Present address:
Fundamental Microbiology and Pathogenicity LaboratoryUMR 5234 CNRS‐University of Bordeaux, SFR TransBioMedBordeauxFrance
| | - Volker Schünemann
- Universität of Kaiserslautern‐LandauDepartment of PhysicsKaiserslauternGermany
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, Collège de France, CNRS UMR 8829Sorbonne UniversitéParis cedex 05France
| | - Béatrice Golinelli‐Pimpaneau
- Laboratoire de Chimie des Processus Biologiques, Collège de France, CNRS UMR 8829Sorbonne UniversitéParis cedex 05France
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49
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Li Y, Lin J, Fu S, Li L, Huang Z, Yang H, Liang X, Qin Y, Zhou J, Liu D, Luo Z. The mystery of transient pregnancy-induced cushing's syndrome: a case report and literature review highlighting GNAS somatic mutations and LHCGR overexpression. Endocrine 2024; 83:473-482. [PMID: 37828397 DOI: 10.1007/s12020-023-03549-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/23/2023] [Indexed: 10/14/2023]
Abstract
PURPOSE Transient pregnancy-induced Cushing's syndrome is a rare condition characterized by the manifestation of symptoms solely during pregnancy, which typically resolve spontaneously following delivery or miscarriage. While it has been established that GNAS is associated with adrenal tumors, its specific role in the pathogenesis of pregnancy-induced Cushing's syndrome remains uncertain.This work aims to examine the association between GNAS mutation and pregnancy-induced Cushing's syndrome. METHODS DNA was extracted from patients' peripheral blood and tumor tissues for whole-exome sequencing (WES) and Sanger sequencing. We used AlphaFold to predict the protein structure of wild-type and mutant GNAS and to make functional predictions, and immunohistochemistry was used to detect disease-associated protein expression. A review and summary of reported cases of transient pregnancy-induced Cushing's syndrome induced by pregnancy was conducted. RESULTS Using WES, we identified a somatic mutation in GNAS (NM_000516, c.C601T, p.R201C) that was predicted to have a deleterious effect using computational methods, such as AlphaFold. Human chorionic gonadotropin (hCG) stimulation tests had weakly positive results, and immunohistochemical staining of adrenal adenoma tissue also revealed positivity for luteinizing hormone/chorionic gonadotropin receptor (LHCGR) and cytochrome P450 family 11 subfamily B member 1 (CYP11B1). We reviewed 15 published cases of transient Cushing's syndrome induced by pregnancy. Among these cases, immunohistochemical staining of the adrenal gland showed positive LHCGR expression in 3 case reports, similar to our findings. CONCLUSION Transient pregnancy-induced Cushing's syndrome may be associated with somatic GNAS mutations and altered adrenal pathology due to abnormal activation of LHCGR.
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Affiliation(s)
- Yufei Li
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Jianfan Lin
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Shien Fu
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Li Li
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Zhenxing Huang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Haiyan Yang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Xinghuan Liang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Yingfen Qin
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Jia Zhou
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Deyun Liu
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China
| | - Zuojie Luo
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, P. R. China.
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50
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Dalton MP, Cheng MH, Bahar I, Coleman JA. Structural mechanisms for VMAT2 inhibition by tetrabenazine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.05.556211. [PMID: 37732203 PMCID: PMC10508774 DOI: 10.1101/2023.09.05.556211] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The vesicular monoamine transporter 2 (VMAT2) is a proton-dependent antiporter responsible for loading monoamine neurotransmitters into synaptic vesicles. Dysregulation of VMAT2 can lead to several neuropsychiatric disorders including Parkinson's disease and schizophrenia. Furthermore, drugs such as amphetamine and MDMA are known to act on VMAT2, exemplifying its role in the mechanisms of actions for drugs of abuse. Despite VMAT2's importance, there remains a critical lack of mechanistic understanding, largely driven by a lack of structural information. Here we report a 3.1 Å resolution cryo-EM structure of VMAT2 complexed with tetrabenazine (TBZ), a non-competitive inhibitor used in the treatment of Huntington's chorea. We find TBZ interacts with residues in a central binding site, locking VMAT2 in an occluded conformation and providing a mechanistic basis for non-competitive inhibition. We further identify residues critical for cytosolic and lumenal gating, including a cluster of hydrophobic residues which are involved in a lumenal gating strategy. Our structure also highlights three distinct polar networks that may determine VMAT2 conformational dynamics and play a role in proton transduction. The structure elucidates mechanisms of VMAT2 inhibition and transport, providing insights into VMAT2 architecture, function, and the design of small-molecule therapeutics.
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Affiliation(s)
- Michael P Dalton
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Mary Hongying Cheng
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ivet Bahar
- Laufer Center for Physical and Quantitative Biology, and Department of Biochemistry and Cell Biology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jonathan A Coleman
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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