168 results match your criteria heterotrimer composed

Complex structure reveals CcmM and CcmN form a heterotrimeric adaptor in β-carboxysome.

Protein Sci 2021 Apr 29. Epub 2021 Apr 29.

Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China.

Carboxysome is an icosahedral self-assembled microcompartment that sequesters RuBisCO and carbonic anhydrases within a selectively permeable protein shell. The scaffolding proteins, CcmM, and CcmN were proposed to act as adaptors that crosslink the enzymatic core to shell facets. However, the details of interaction pattern remain unknown. Read More

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Generation of Fluorescent Versions of Saccharomyces cerevisiae RPA to Study the Conformational Dynamics of Its ssDNA-Binding Domains.

Methods Mol Biol 2021 ;2281:151-168

Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA.

Replication protein A (RPA) is an essential single-stranded DNA (ssDNA)-binding protein that sequesters ssDNA and protects it from nucleolytic degradation. The RPA-ssDNA nucleoprotein acts as a hub to recruit over two dozen DNA metabolic enzymes onto ssDNA to coordinate DNA replication, repair, and recombination. RPA functions as a heterotrimer composed of RPA70, RPA32, and RPA14 subunits and has multiple DNA-binding and protein-interaction domains. Read More

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January 2021

BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in oocytes.

Elife 2020 12 23;9. Epub 2020 Dec 23.

Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, United Kingdom.

Protein Phosphatase 2A (PP2A) is a heterotrimer composed of scaffolding (A), catalytic (C), and regulatory (B) subunits. PP2A complexes with B56 subunits are targeted by Shugoshin and BUBR1 to protect centromeric cohesion and stabilise kinetochore-microtubule attachments in yeast and mouse meiosis. In , the closest BUBR1 orthologue lacks the B56-interaction domain and Shugoshin is not required for meiotic segregation. Read More

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December 2020

Expression of laminin-5 gamma 2 chain predicts invasion of extramammary Paget's disease cell.

APMIS 2021 Jan 21;129(1):3-8. Epub 2020 Oct 21.

Departments of Surgery and Science, Faculty of Medicine, Academic Assembly, University of Toyama, Toyama City, Japan.

Extramammary Paget's disease (EMPD) is a rare malignant skin neoplasm characterized by intraepidermal proliferation of tumor cells. The tumor cells of EMPD may sometimes invade into the dermis or metastasize into the regional lymph nodes. Several studies have proposed mechanisms underlying the increased invasiveness of EMPD; however, molecular markers indicating invasiveness have yet to be well characterized. Read More

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January 2021

A Heterotrimeric Dehydrogenase Complex Functions with 2 Distinct YcaO Proteins to Install 5 Azole Heterocycles into 35-Membered Sulfomycin Thiopeptides.

J Am Chem Soc 2020 05 24;142(18):8454-8463. Epub 2020 Apr 24.

State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.

Sulfomycins are sulfur-rich, ribosomally synthesized, and post-translationally modified peptides (RiPPs) that are characterized by a 35-membered macrocyclic ring system with a pyridine domain central to five azoles and additional dehydroamino acids. The pathway through which these large thiopeptide antibiotics are formed in remains elusive. Starting with the cloning of the biosynthetic gene cluster of sulfomycins, we here dissect a two-stage process in which an unusual dehydrogenase heterotrimer functions with two distinct YcaO proteins to install five azole heterocycles into the core peptide sequence of the precursor peptide. Read More

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Reduction of protein phosphatase 2A (PP2A) complexity reveals cellular functions and dephosphorylation motifs of the PP2A/B'δ holoenzyme.

J Biol Chem 2020 04 10;295(17):5654-5668. Epub 2020 Mar 10.

Department of Neuroscience and Pharmacology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242. Electronic address:

Protein phosphatase 2A (PP2A) is a large enzyme family responsible for most cellular Ser/Thr dephosphorylation events. PP2A substrate specificity, localization, and regulation by second messengers rely on more than a dozen regulatory subunits (including B/R2, B'/R5, and B″/R3), which form the PP2A heterotrimeric holoenzyme by associating with a dimer comprising scaffolding (A) and catalytic (C) subunits. Because of partial redundancy and high endogenous expression of PP2A holoenzymes, traditional approaches of overexpressing, knocking down, or knocking out PP2A regulatory subunits have yielded only limited insights into their biological roles and substrates. Read More

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Photoreactive DNA as a Tool to Study Replication Protein A Functioning in DNA Replication and Repair.

Photochem Photobiol 2020 03 5;96(2):440-449. Epub 2020 Mar 5.

Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia.

Replication protein A (RPA), eukaryotic single-stranded DNA-binding protein, is a key player in multiple processes of DNA metabolism including DNA replication, recombination and DNA repair. Human RPA composed of subunits of 70-, 32- and 14-kDa binds ssDNA with high affinity and interacts specifically with multiple proteins. The RPA heterotrimer binds ssDNA in several modes, with occlusion lengths of 8-10, 13-22 and 30 nucleotides corresponding to global, transitional and elongated conformations of protein. Read More

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Nucleotide exchange-dependent and nucleotide exchange-independent functions of plant heterotrimeric GTP-binding proteins.

Sci Signal 2019 11 5;12(606). Epub 2019 Nov 5.

Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia.

Heterotrimeric guanine nucleotide-binding proteins (G proteins), which are composed of α, β, and γ subunits, are versatile, guanine nucleotide-dependent, molecular on-off switches. In animals and fungi, the exchange of GDP for GTP on Gα controls G protein activation and is crucial for normal cellular responses to diverse extracellular signals. The model plant has a single canonical Gα subunit, AtGPA1. Read More

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November 2019

The PvNF-YA1 and PvNF-YB7 Subunits of the Heterotrimeric NF-Y Transcription Factor Influence Strain Preference in the Symbiosis.

Front Plant Sci 2019 28;10:221. Epub 2019 Feb 28.

Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata - Centro Científico y Tecnológico La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Argentina.

Transcription factors of the Nuclear Factor Y (NF-Y) family play essential functions in plant development and plasticity, including the formation of lateral root organs such as lateral root and symbiotic nodules. NF-Ys mediate transcriptional responses by acting as heterotrimers composed of three subunits, NF-YA, NF-YB, and NF-YC, which in plants are encoded by relatively large gene families. We have previously shown that, in the × interaction, the PvNF-YC1 subunit is involved not only in the formation of symbiotic nodules, but also in the preference exhibited by the plant for rhizobial strains that are more efficient and competitive in nodule formation. Read More

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February 2019

Structure of the human epithelial sodium channel by cryo-electron microscopy.

Elife 2018 09 25;7. Epub 2018 Sep 25.

Vollum Institute, Oregon Health and Science University, Portland, United States.

The epithelial sodium channel (ENaC), a member of the ENaC/DEG superfamily, regulates Na and water homeostasis. ENaCs assemble as heterotrimeric channels that harbor protease-sensitive domains critical for gating the channel. Here, we present the structure of human ENaC in the uncleaved state determined by single-particle cryo-electron microscopy. Read More

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September 2018

Protein phosphatase 2A is crucial for sarcomere organization in Caenorhabditis elegans striated muscle.

Mol Biol Cell 2018 08 27;29(17):2084-2097. Epub 2018 Jun 27.

Department of Pathology, Emory University, Atlanta, GA 30322.

Protein phosphatase 2A (PP2A) is a heterotrimer composed of single catalytic and scaffolding subunits and one of several possible regulatory subunits. We identified PPTR-2, a regulatory subunit of PP2A, as a binding partner for the giant muscle protein UNC-89 (obscurin) in Caenorhabditis elegans. PPTR-2 is required for sarcomere organization when its paralogue, PPTR-1, is deficient. Read More

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A Mechanism for the Activation of the Influenza Virus Transcriptase.

Mol Cell 2018 06 14;70(6):1101-1110.e4. Epub 2018 Jun 14.

Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK. Electronic address:

Influenza virus RNA polymerase (FluPol), a heterotrimer composed of PB1, PB2, and PA subunits (P3 in influenza C), performs both transcription and replication of the viral RNA genome. For transcription, FluPol interacts with the C-terminal domain (CTD) of RNA polymerase II (Pol II), which enables FluPol to snatch capped RNA primers from nascent host RNAs. Here, we describe the co-crystal structure of influenza C virus polymerase (FluPol) bound to a Ser5-phosphorylated CTD (pS-CTD) peptide. Read More

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Heterotrimeric G-Protein γ Subunit CsGG3.2 Positively Regulates the Expression of Genes and Chilling Tolerance in Cucumber.

Front Plant Sci 2018 17;9:488. Epub 2018 Apr 17.

Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.

Heterotrimeric guanine nucleotide-binding proteins (G proteins) composed of alpha (Gα), beta (Gβ), and gamma (Gγ) subunits are central signal transducers mediating the cellular response to multiple stimuli, such as cold, in eukaryotes. Plant Gγ subunits, divided into A, B, and C three structurally distinct types, provide proper cellular localization and functional specificity to the heterotrimer complex. Here, we demonstrate that a type C Gγ subunit CsGG3. Read More

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Novel Cu Labeled RGD-BBN Heterotrimers for PET Imaging of Prostate Cancer.

Bioconjug Chem 2018 05 13;29(5):1595-1604. Epub 2018 Apr 13.

Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program , Stanford University , Stanford , California 94305-5344 , United States.

Bombesin receptor 2 (BB) and integrin αβ receptor are privileged targets for molecular imaging of cancer because of their overexpression in a number of tumor tissues. The most recent developments in heterodimer-based radiopharmaceuticals concern BB- and integrin αβ-targeting compounds, consisting of bombesin (BBN) and cyclic arginine-glycine-aspartic acid peptides (RGD), connected through short length linkers. Molecular imaging probes based on RGD-BBN heterodimer design exhibit improved tumor targeting efficacy compared to the single-receptor targeting peptide monomers. Read More

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A Functional Signature Ontology (FUSION) screen detects an AMPK inhibitor with selective toxicity toward human colon tumor cells.

Sci Rep 2018 02 28;8(1):3770. Epub 2018 Feb 28.

Eppley Institute, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA.

AMPK is a serine threonine kinase composed of a heterotrimer of a catalytic, kinase-containing α and regulatory β and γ subunits. Here we show that individual AMPK subunit expression and requirement for survival varies across colon cancer cell lines. While AMPKα1 expression is relatively consistent across colon cancer cell lines, AMPKα1 depletion does not induce cell death. Read More

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February 2018

Retriever is a multiprotein complex for retromer-independent endosomal cargo recycling.

Nat Cell Biol 2017 Oct 11;19(10):1214-1225. Epub 2017 Sep 11.

School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK.

Following endocytosis into the endosomal network, integral membrane proteins undergo sorting for lysosomal degradation or are retrieved and recycled back to the cell surface. Here we describe the discovery of an ancient and conserved multiprotein complex that orchestrates cargo retrieval and recycling and, importantly, is biochemically and functionally distinct from the established retromer pathway. We have called this complex 'retriever'; it is a heterotrimer composed of DSCR3, C16orf62 and VPS29, and bears striking similarity to retromer. Read More

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October 2017

Prerequisites for the acquisition of mammalian pathogenicity by influenza A virus with a prototypic avian PB2 gene.

Sci Rep 2017 08 31;7(1):10205. Epub 2017 Aug 31.

Laboratory of Poultry Production Medicine, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea.

The polymerase of avian influenza A virus (AIV) is a heterotrimer composed of PB2, PB1, and PA. PB2 plays a role in overcoming the host barrier; however, the genetic prerequisites for avian PB2 to acquire mammalian pathogenic mutations have not been well elucidated. Previously, we identified a prototypic avian PB2 that conferred non-replicative and non-pathogenic traits to a PR8-derived recombinant virus when it was used to infect mice. Read More

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Biochemical characterization of recombinant influenza A polymerase heterotrimer complex: Endonuclease activity and evaluation of inhibitors.

PLoS One 2017 15;12(8):e0181969. Epub 2017 Aug 15.

Gilead Sciences, Inc., Foster City, California, United States of America.

Influenza polymerase is a heterotrimer composed of polymerase acidic protein A (PA) and basic proteins 1 (PB1) and 2 (PB2). The endonuclease active site, located in the PA subunit, cleaves host mRNA to prime viral mRNA transcription, and is essential for viral replication. To date, the human influenza A endonuclease activity has only been studied on the truncated active-site containing N-terminal domain of PA (PAN) or full-length PA in the absence of PB1 or PB2. Read More

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October 2017

Design of bFGF-tethered self-assembling extracellular matrix proteins via coiled-coil triple-helix formation.

Biomed Mater 2017 Aug 9;12(4):045021. Epub 2017 Aug 9.

School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.

Self-assembling peptides are attractive materials for tissue engineering applications because of their functionality including high biocompatibility and biodegradability. Modification of self-assembling peptides with functional motifs, such as the cell-adhesive tripeptide sequence RGD leads to functional artificial extracellular matrices (ECMs). In this study, we developed an artificial self-assembling ECM protein tethered with a growth factor via heterotrimer triple-helix (helix A/B/C) formation. Read More

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Formation of AAB-Type Collagen Heterotrimers from Designed Cationic and Aromatic Collagen-Mimetic Peptides: Evaluation of the C-Terminal Cation-π Interactions.

Biomacromolecules 2017 03 16;18(3):985-993. Epub 2017 Feb 16.

Department of Chemistry and ‡Frontier Research Center on Fundamental and Applied Science of Matters, National Tsing Hua University , 101 Sec. 2 Kuang-Fu Rd., Hsinchu, Taiwan 30013, ROC.

Most of natural collagens are heterotrimers composed of two (AAB) or three (ABC) different peptide chains, and thus heterotrimeric constructs are preferable to mimic natural collagens. Exploring the forces to assemble synthetic collagen-mimetic peptides (CMPs) into heterotrimers has been an attractive topic in preparing collagen-related biomaterials. Here we designed and synthesized two cationic CMPs (CR and CK) in which multiple Arg or Lys residues are installed in their C-terminal region, and one aromatic CMP (CF) whose C-terminal end contains multiple Phe residues. Read More

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ASIC and ENaC type sodium channels: conformational states and the structures of the ion selectivity filters.

Israel Hanukoglu

FEBS J 2017 02 15;284(4):525-545. Epub 2016 Sep 15.

Laboratory of Cell Biology, Ariel University, Israel.

The acid-sensing ion channels (ASICs) and epithelial sodium channels (ENaC) are members of a superfamily of channels that play critical roles in mechanosensation, chemosensation, nociception, and regulation of blood volume and pressure. These channels look and function like a tripartite funnel that directs the flow of Na ions into the cytoplasm via the channel pore in the membrane. The subunits that form these channels share a common structure with two transmembrane segments (TM1 and TM2) and a large extracellular part. Read More

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February 2017

Assembly of Multi-Phthalocyanines on a Porphyrin Template by Fourfold Rotaxane Formation.

Chemistry 2016 Aug 15;22(35):12371-80. Epub 2016 Jul 15.

Department of Chemistry, Faculty of Science, Nagoya University, Furo-cho, Chikusa-ku, Naogya, 464-8602, Japan.

A stacked assembly composed of a porphyrin and two phthalocyanines was prepared through fourfold rotaxane formation. Two phthalocyanine molecules, bearing four 24-crown-8 units, were assembled onto a porphyrin template incorporating four sidechains with two dialkylammonium ions each through pseudorotaxane formation between crown ether units and ammonium ions. The Staudinger phosphite reaction, as the stoppering reaction, resulted in the formation of the stacked heterotrimer composed of a porphyrin and two phthalocyanines connected through a fourfold rotaxane structure. Read More

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Three proliferating cell nuclear antigen homologues from Metallosphaera sedula form a head-to-tail heterotrimer.

Sci Rep 2016 05 27;6:26588. Epub 2016 May 27.

Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

Proliferating cell nuclear antigen (PCNA) is a sliding clamp that plays a key role in DNA metabolism. Genome sequence analysis has revealed that some crenarchaea possess three PCNA genes in their genome, but it has been reported that three PCNAs do not always form a unique heterotrimer composed of one of each molecule. The thermoacidophilic archaeon, Metallosphaera sedula, has three PCNA homologue genes. Read More

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Replication protein A and more: single-stranded DNA-binding proteins in eukaryotic cells.

Ting Liu Jun Huang

Acta Biochim Biophys Sin (Shanghai) 2016 Jul 4;48(7):665-70. Epub 2016 May 4.

Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou 310058, China

Single-stranded DNA-binding proteins (SSBs) play essential roles in DNA replication, recombinational repair, and maintenance of genome stability. In human, the major SSB, replication protein A (RPA), is a stable heterotrimer composed of subunits of RPA1, RPA2, and RPA3, each of which is conserved not only in mammals but also in all other eukaryotic species. In addition to RPA, other SSBs have also been identified in the human genome, including sensor of single-stranded DNA complexes 1 and 2 (SOSS1/2). Read More

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Spontaneous Helical Structure Formation in Laminin Nanofibers.

J Mater Chem B 2015 Oct 21;3(40):7993-8000. Epub 2015 Aug 21.

Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15219, USA ; Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15219, USA.

Laminin is a cross-shaped heterotrimer composed of three polypeptides chains that assembles into an insoluble extracellular matrix (ECM) network as part of the basement membrane, serving a vital role in many processes such as embryonic development, differentiation, and muscle and nerve regeneration. Here we engineered monodisperse laminin nanofibers using a surface-initiated assembly technique in order to investigate how changes in protein composition affect formation and structure of the network. Specifically, we compared laminin 111 with varying degrees of purity and with and without entactin to determine whether these changes alter biophysical properties. Read More

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October 2015

A heterotrimer model of the complete Microprocessor complex revealed by single-molecule subunit counting.

RNA 2016 Feb 18;22(2):175-83. Epub 2015 Dec 18.

Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06536, USA.

During microRNA (miRNA) biogenesis, the Microprocessor complex (MC), composed minimally of Drosha, an RNaseIII enzyme, and DGCR8, a double-stranded RNA-binding protein, cleaves the primary-miRNA (pri-miRNA) to release the pre-miRNA stem-loop structure. Size-exclusion chromatography of the MC, isolated from mammalian cells, suggested multiple copies of one or both proteins in the complex. However, the exact stoichiometry was unknown. Read More

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February 2016

Type B Heterotrimeric G Protein γ-Subunit Regulates Auxin and ABA Signaling in Tomato.

Plant Physiol 2016 Feb 14;170(2):1117-34. Epub 2015 Dec 14.

Plant Genetic Engineering Laboratory (G.S., Y.T., J.R.B.) and Centre for Integrative Legume Research (S.H., J.B.), School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia; andInstituto de Horticultura Subtropical y Mediterranea La Mayora, Consejo Superior de Investigaciones Científicas, Universidad de Malaga, Experimental Station La Mayora, 29750 Algarrobo-Costa, Malaga, Spain (C.L.-E.)

Heterotrimeric G proteins composed of α, β, and γ subunits are central signal transducers mediating the cellular response to multiple stimuli in most eukaryotes. Gγ subunits provide proper cellular localization and functional specificity to the heterotrimer complex. Plant Gγ subunits, divided into three structurally distinct types, are more diverse than their animal counterparts. Read More

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February 2016

B'-protein phosphatase 2A is a functional binding partner of delta-retroviral integrase.

Nucleic Acids Res 2016 Jan 10;44(1):364-76. Epub 2015 Dec 10.

Division of Infectious Diseases, St. Mary's campus, Imperial College London, Norfolk Place, London, W2 1PG, UK

To establish infection, a retrovirus must insert a DNA copy of its RNA genome into host chromatin. This reaction is catalysed by the virally encoded enzyme integrase (IN) and is facilitated by viral genus-specific host factors. Herein, cellular serine/threonine protein phosphatase 2A (PP2A) is identified as a functional IN binding partner exclusive to δ-retroviruses, including human T cell lymphotropic virus type 1 and 2 (HTLV-1 and HTLV-2) and bovine leukaemia virus (BLV). Read More

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January 2016

Retention and splicing complex (RES) - the importance of cooperativity.

RNA Biol 2016 19;13(2):128-33. Epub 2015 Oct 19.

a Department for NMR-based Structural Biology ; Max Planck Institute for Biophysical Chemistry ; Am Fassberg 11, Göttingen , Germany.

One of the great challenges to structural biologists lies in explaining the complexities of the spliceosome - a ribosome-sized molecular machine that is assembled in a step-wise manner and is responsible for pre-mRNA splicing. The spliceosome is both fascinating and difficult to work with, because of its dynamic nature. At each discrete step of splicing tens of proteins come and go orchestrating the functional transition through massive structural rearrangements. Read More

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November 2016

Reconstitution and structure of a bacterial Pnkp1-Rnl-Hen1 RNA repair complex.

Nat Commun 2015 Apr 17;6:6876. Epub 2015 Apr 17.

Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.

Ribotoxins cleave essential RNAs for cell killing, and RNA repair neutralizes the damage inflicted by ribotoxins for cell survival. Here we report a new bacterial RNA repair complex that performs RNA repair linked to immunity. This new RNA repair complex is a 270-kDa heterohexamer composed of three proteins-Pnkp1, Rnl and Hen1-that are required to repair ribotoxin-cleaved RNA in vitro. Read More

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