1
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Folger IB, Frota NF, Pistofidis A, Niquille DL, Hansen DA, Schmeing TM, Hilvert D. High-throughput reprogramming of an NRPS condensation domain. Nat Chem Biol 2024:10.1038/s41589-023-01532-x. [PMID: 38308044 DOI: 10.1038/s41589-023-01532-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 12/19/2023] [Indexed: 02/04/2024]
Abstract
Engineered biosynthetic assembly lines could revolutionize the sustainable production of bioactive natural product analogs. Although yeast display is a proven, powerful tool for altering the substrate specificity of gatekeeper adenylation domains in nonribosomal peptide synthetases (NRPSs), comparable strategies for other components of these megaenzymes have not been described. Here we report a high-throughput approach for engineering condensation (C) domains responsible for peptide elongation. We show that a 120-kDa NRPS module, displayed in functional form on yeast, can productively interact with an upstream module, provided in solution, to produce amide products tethered to the yeast surface. Using this system to screen a large C-domain library, we reprogrammed a surfactin synthetase module to accept a fatty acid donor, increasing catalytic efficiency for this noncanonical substrate >40-fold. Because C domains can function as selectivity filters in NRPSs, this methodology should facilitate the precision engineering of these molecular assembly lines.
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Affiliation(s)
- Ines B Folger
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland
| | - Natália F Frota
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - Angelos Pistofidis
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - David L Niquille
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland
| | - Douglas A Hansen
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland
| | - T Martin Schmeing
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland.
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2
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Cencic R, Im YK, Naineni SK, Moustafa-Kamal M, Jovanovic P, Sabourin V, Annis MG, Robert F, Schmeing TM, Koromilas A, Paquet M, Teodoro JG, Huang S, Siegel PM, Topisirovic I, Ursini-Siegel J, Pelletier J. A second-generation eIF4A RNA helicase inhibitor exploits translational reprogramming as a vulnerability in triple-negative breast cancer. Proc Natl Acad Sci U S A 2024; 121:e2318093121. [PMID: 38232291 PMCID: PMC10823175 DOI: 10.1073/pnas.2318093121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/15/2023] [Indexed: 01/19/2024] Open
Abstract
In this study, we aimed to address the current limitations of therapies for macro-metastatic triple-negative breast cancer (TNBC) and provide a therapeutic lead that overcomes the high degree of heterogeneity associated with this disease. Specifically, we focused on well-documented but clinically underexploited cancer-fueling perturbations in mRNA translation as a potential therapeutic vulnerability. We therefore developed an orally bioavailable rocaglate-based molecule, MG-002, which hinders ribosome recruitment and scanning via unscheduled and non-productive RNA clamping by the eukaryotic translation initiation factor (eIF) 4A RNA helicase. We demonstrate that MG-002 potently inhibits mRNA translation and primary TNBC tumor growth without causing overt toxicity in mice. Importantly, given that metastatic spread is a major cause of mortality in TNBC, we show that MG-002 attenuates metastasis in pre-clinical models. We report on MG-002, a rocaglate that shows superior properties relative to existing eIF4A inhibitors in pre-clinical models. Our study also paves the way for future clinical trials exploring the potential of MG-002 in TNBC and other oncological indications.
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Affiliation(s)
- Regina Cencic
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Young K. Im
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
| | - Sai Kiran Naineni
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Mohamed Moustafa-Kamal
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Predrag Jovanovic
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
| | - Valerie Sabourin
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
| | - Matthew G. Annis
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Francis Robert
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - T. Martin Schmeing
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Antonis Koromilas
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QCH4A 3T2, Canada
| | - Marilène Paquet
- Département de pathologie et de microbiologie, Faculté de médecine vétérinaire, Université de Montréal, Montréal, QCH3C 3J7, Canada
| | - Jose G. Teodoro
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Sidong Huang
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
| | - Peter M. Siegel
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QCH4A 3T2, Canada
- Department of Medicine, McGill University, Montreal, QCH4A 3J1, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QCH4A 3T2, Canada
| | - Josie Ursini-Siegel
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Lady Davis Institute for Medical Research, Montreal, QCH3T 1E2, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QCH4A 3T2, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
- Division of Experimental Medicine, McGill University, Montreal, QCH4A 3J1, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QCH4A 3T2, Canada
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3
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Sharon I, Hilvert D, Schmeing TM. Cyanophycin and its biosynthesis: not hot but very cool. Nat Prod Rep 2023; 40:1479-1497. [PMID: 37231979 DOI: 10.1039/d2np00092j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Covering: 1878 to early 2023Cyanophycin is a biopolymer consisting of a poly-aspartate backbone with arginines linked to each Asp sidechain through isopeptide bonds. Cyanophycin is made by cyanophycin synthetase 1 or 2 through ATP-dependent polymerization of Asp and Arg, or β-Asp-Arg, respectively. It is degraded into dipeptides by exo-cyanophycinases, and these dipeptides are hydrolyzed into free amino acids by general or dedicated isodipeptidase enzymes. When synthesized, chains of cyanophycin coalesce into large, inert, membrane-less granules. Although discovered in cyanobacteria, cyanophycin is made by species throughout the bacterial kingdom, and cyanophycin metabolism provides advantages for toxic bloom forming algae and some human pathogens. Some bacteria have developed dedicated schemes for cyanophycin accumulation and use, which include fine temporal and spatial regulation. Cyanophycin has also been heterologously produced in a variety of host organisms to a remarkable level, over 50% of the host's dry mass, and has potential for a variety of green industrial applications. In this review, we summarize the progression of cyanophycin research, with an emphasis on recent structural studies of enzymes in the cyanophycin biosynthetic pathway. These include several unexpected revelations that show cyanophycin synthetase to be a very cool, multi-functional macromolecular machine.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, QC, Canada, H3G 0B1.
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - T Martin Schmeing
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, QC, Canada, H3G 0B1.
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4
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Swain K, Sharon I, Blackson W, Parrish S, Tekel S, Schmeing TM, Nielsen DR, Nannenga BL. Soluble and stable cyanophycin synthetase expression enhances heterologous cyanophycin production in Escherichia coli. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
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5
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Naineni SK, Cencic R, Robert F, Brown LE, Haque M, Scott-Talib J, Sénéchal P, Schmeing TM, Porco JA, Pelletier J. Exploring the targeting spectrum of rocaglates among eIF4A homologs. RNA 2023; 29:826-835. [PMID: 36882295 PMCID: PMC10187672 DOI: 10.1261/rna.079318.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 02/16/2023] [Indexed: 05/18/2023]
Abstract
Inhibition of eukaryotic translation initiation through unscheduled RNA clamping of the DEAD-box (DDX) RNA helicases eIF4A1 and eIF4A2 has been documented for pateamine A (PatA) and rocaglates-two structurally different classes of compounds that share overlapping binding sites on eIF4A. Clamping of eIF4A to RNA causes steric blocks that interfere with ribosome binding and scanning, rationalizing the potency of these molecules since not all eIF4A molecules need to be engaged to elicit a biological effect. In addition to targeting translation, PatA and analogs have also been shown to target the eIF4A homolog, eIF4A3-a helicase necessary for exon junction complex (EJC) formation. EJCs are deposited on mRNAs upstream of exon-exon junctions and, when present downstream from premature termination codons (PTCs), participate in nonsense-mediated decay (NMD), a quality control mechanism aimed at preventing the production of dominant-negative or gain-of-function polypeptides from faulty mRNA transcripts. We find that rocaglates can also interact with eIF4A3 to induce RNA clamping. Rocaglates also inhibit EJC-dependent NMD in mammalian cells, but this does not appear to be due to induced eIF4A3-RNA clamping, but rather a secondary consequence of translation inhibition incurred by clamping eIF4A1 and eIF4A2 to mRNA.
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Affiliation(s)
- Sai Kiran Naineni
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
| | - Regina Cencic
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
| | - Francis Robert
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
| | - Lauren E Brown
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Massachusetts 02215, USA
| | - Minza Haque
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
| | | | - Patrick Sénéchal
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
- Centre de Recherche en Biologie Structurale (CRBS), McGill University, Quebec, H3G 0B1 Canada
| | - John A Porco
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Massachusetts 02215, USA
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Quebec, H3G 1Y6 Canada
- Centre de Recherche en Biologie Structurale (CRBS), McGill University, Quebec, H3G 0B1 Canada
- McGill Research Center on Complex Traits, McGill University, Quebec, H3G 0B1 Canada
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, Quebec, H3A 1A3 Canada
- Department of Oncology, McGill University, Quebec, H4A 3T2 Canada
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6
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Markus LMD, Sharon I, Munro K, Grogg M, Hilvert D, Strauss M, Schmeing TM. Structure and function of a hexameric cyanophycin synthetase 2. Protein Sci 2023:e4685. [PMID: 37222490 DOI: 10.1002/pro.4685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/20/2023] [Accepted: 05/22/2023] [Indexed: 05/25/2023]
Abstract
Cyanophycin is a natural polymer composed of a poly-aspartate backbone with arginine attached to each of the aspartate sidechains. Produced by a wide range of bacteria, which mainly use it as a store of fixed nitrogen, it has many promising industrial applications. Cyanophycin can be synthesized from the amino acids Asp and Arg by the widespread cyanophycin synthetase 1 (CphA1), or from the dipeptide β-Asp-Arg by the cyanobacterial enzyme cyanophycin synthetase 2 (CphA2). CphA2 enzymes display a range of oligomeric states, from dimers to dodecamers. Recently, the crystal structure of a CphA2 dimer was solved but could not be obtained in complex with substrate. Here, we report cryo-EM structures of the hexameric CphA2 from Stanieria sp. at ~2.8 Å resolution, both with and without ATP analog and cyanophycin. The structures show a two-fold symmetrical, trimer-of-dimers hexameric architecture, and substrate-binding interactions that are similar to those of CphA1. Mutagenesis experiments demonstrate the importance of several conserved substrate-binding residues. We also find that a Q416A/R528G double mutation prevents hexamer formation and use this double mutant to show that hexamerization augments the rate of cyanophycin synthesis. Together, these results increase our mechanistic understanding of how an interesting green polymer is biosynthesized. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Linda M D Markus
- Department of Biochemistry Montréal, QC, Canada
- Centre de recherche en biologie structurale Montréal, QC, Canada
| | - Itai Sharon
- Department of Biochemistry Montréal, QC, Canada
- Centre de recherche en biologie structurale Montréal, QC, Canada
| | - Kim Munro
- Centre de recherche en biologie structurale Montréal, QC, Canada
| | - Marcel Grogg
- Laboratory of Organic Chemistry, ETH Zürich, Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, Zürich, Switzerland
| | - Mike Strauss
- Department of Biochemistry Montréal, QC, Canada
- Department of Anatomy and Cell Biology McGill University Montréal, QC, Canada
| | - T Martin Schmeing
- Department of Biochemistry Montréal, QC, Canada
- Centre de recherche en biologie structurale Montréal, QC, Canada
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7
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Sharon I, Schmeing TM. Bioinformatics of cyanophycin metabolism genes and characterization of promiscuous isoaspartyl dipeptidases that catalyze the final step of cyanophycin degradation. Sci Rep 2023; 13:8314. [PMID: 37221236 DOI: 10.1038/s41598-023-34587-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/03/2023] [Indexed: 05/25/2023] Open
Abstract
Cyanophycin is a bacterial biopolymer used for storage of fixed nitrogen. It is composed of a backbone of L-aspartate residues with L-arginines attached to each of their side chains. Cyanophycin is produced by cyanophycin synthetase 1 (CphA1) using Arg, Asp and ATP, and is degraded in two steps. First, cyanophycinase breaks down the backbone peptide bonds, releasing β-Asp-Arg dipeptides. Then, these dipeptides are broken down into free Asp and Arg by enzymes with isoaspartyl dipeptidase activity. Two bacterial enzymes are known to possess promiscuous isoaspartyl dipeptidase activity: isoaspartyl dipeptidase (IadA) and isoaspartyl aminopeptidase (IaaA). We performed a bioinformatic analysis to investigate whether genes for cyanophycin metabolism enzymes cluster together or are spread around the microbial genomes. Many genomes showed incomplete contingents of known cyanophycin metabolizing genes, with different patterns in various bacterial clades. Cyanophycin synthetase and cyanophycinase are usually clustered together when recognizable genes for each are found within a genome. Cyanophycinase and isoaspartyl dipeptidase genes typically cluster within genomes lacking cphA1. About one-third of genomes with genes for CphA1, cyanophycinase and IaaA show these genes clustered together, while the proportion is around one-sixth for CphA1, cyanophycinase and IadA. We used X-ray crystallography and biochemical studies to characterize an IadA and an IaaA from two such clusters, in Leucothrix mucor and Roseivivax halodurans, respectively. The enzymes retained their promiscuous nature, showing that being associated with cyanophycin-related genes did not make them specific for β-Asp-Arg dipeptides derived from cyanophycin degradation.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada
| | - T Martin Schmeing
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada.
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Burns L, Giannakopoulou N, Zhu L, Xu YZ, Khan RH, Bekal S, Schurr E, Schmeing TM, Gruenheid S. A229 THE BACTERIAL VIRULENCE FACTOR NLEA UNDERGOES HOST-MEDIATED O-LINKED GLYCOSYLATION. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991285 DOI: 10.1093/jcag/gwac036.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
NOT PUBLISHED AT AUTHOR’S REQUEST
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Affiliation(s)
| | | | - L Zhu
- Microbiology & Immunology
| | - Y Z Xu
- Medicine, McGill University, Montreal
| | - R H Khan
- Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue,Microbiologie, Infectologie et Immunologie, Universite de Montreal, Montreal
| | - S Bekal
- Microbiologie, Infectologie et Immunologie, Universite de Montreal, Montreal,Institut National de Sante Publique du Quebec, Sainte-Anne-de-Bellevue
| | - E Schurr
- Biochemistry, McGill University, Montreal, Canada
| | - T M Schmeing
- Biochemistry, McGill University, Montreal, Canada
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9
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Sharon I, McKay GA, Nguyen D, Schmeing TM. Discovery of cyanophycin dipeptide hydrolase enzymes suggests widespread utility of the natural biopolymer cyanophycin. Proc Natl Acad Sci U S A 2023; 120:e2216547120. [PMID: 36800389 PMCID: PMC9974463 DOI: 10.1073/pnas.2216547120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/19/2023] [Indexed: 02/18/2023] Open
Abstract
Cyanophycin is a bacterial polymer mainly used for nitrogen storage. It is composed of a peptide backbone of L-aspartate residues with L-arginines attached to their side chains through isopeptide bonds. Cyanophycin is degraded in two steps: Cyanophycinase cleaves the polymer into β-Asp-Arg dipeptides, which are hydrolyzed into free Asp and Arg by enzymes possessing isoaspartyl dipeptide hydrolase activity. Two unrelated enzymes with this activity, isoaspartyl dipeptidase (IadA) and isoaspartyl aminopeptidase (IaaA) have been shown to degrade β-Asp-Arg dipeptides, but bacteria which encode cyanophycin-metabolizing genes can lack iaaA and iadA genes. In this study, we investigate a previously uncharacterized enzyme whose gene can cluster with cyanophycin-metabolizing genes. This enzyme, which we name cyanophycin dipeptide hydrolase (CphZ), is specific for dipeptides derived from cyanophycin degradation. Accordingly, a co-complex structure of CphZ and β-Asp-Arg shows that CphZ, unlike IadA or IaaA, recognizes all portions of its β-Asp-Arg substrate. Bioinformatic analyses showed that CphZ is found in very many proteobacteria and is homologous to an uncharacterized protein encoded in the "arginine/ornithine transport" (aot) operon of many pseudomonas species, including Pseudomonas aeruginosa. In vitro assays show that AotO is indeed a CphZ, and in cellulo growth experiments show that this enzyme and the aot operon allow P. aeruginosa to take up and use β-Asp-Arg as a sole carbon and nitrogen source. Together the results establish the novel, highly specific enzyme subfamily of CphZs, suggesting that cyanophycin is potentially used by a much wider range of bacteria than previously appreciated.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry, McGill University, Montréal, QCH3G 0B1, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, QCH3G 0B1, Canada
| | - Geoffrey A. McKay
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montréal, QCH4A 3J1, Canada
| | - Dao Nguyen
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montréal, QCH4A 3J1, Canada
| | - T. Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QCH3G 0B1, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, QCH3G 0B1, Canada
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10
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Burns L, Giannakopoulou N, Zhu L, Xu YZ, Khan RH, Bekal S, Schurr E, Schmeing TM, Gruenheid S. The bacterial virulence factor NleA undergoes host-mediated O-linked glycosylation. Mol Microbiol 2023; 119:161-173. [PMID: 36196760 DOI: 10.1111/mmi.14989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 09/01/2022] [Accepted: 09/29/2022] [Indexed: 11/28/2022]
Abstract
Enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) are gastrointestinal pathogens responsible for severe diarrheal illness. EHEC and EPEC form "attaching and effacing" lesions during colonization and, upon adherence, inject proteins directly into host intestinal cells via the type III secretion system (T3SS). Injected bacterial proteins have a variety of functions but generally alter host cell biology to favor survival and/or replication of the pathogen. Non-LEE-encoded effector A (NleA) is a T3SS-injected effector of EHEC, EPEC, and the related mouse pathogen Citrobacter rodentium. Studies in mouse models indicate that NleA has an important role in bacterial virulence. However, the mechanism by which NleA contributes to disease remains unknown. We have determined that the following translocation into host cells, a serine and threonine-rich region of NleA is modified by host-mediated mucin-type O-linked glycosylation. Surprisingly, this region was not present in several clinical EHEC isolates. When expressed in C. rodentium, a non-modifiable variant of NleA was indistinguishable from wildtype NleA in an acute mortality model but conferred a modest increase in persistence over the course of infection in mixed infections in C57BL/6J mice. This is the first known example of a bacterial effector being modified by host-mediated O-linked glycosylation. Our data also suggests that this modification may confer a selective disadvantage to the bacteria during in vivo infection.
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Affiliation(s)
- Lindsay Burns
- McGill Research Centre on Complex Traits and Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
| | - Natalia Giannakopoulou
- McGill Research Centre on Complex Traits and Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
| | - Lei Zhu
- McGill Research Centre on Complex Traits and Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
| | - Yong Zhong Xu
- Program in Infectious Diseases and Global Health, The Research Institute of the McGill University Health Centre and McGill International TB Centre, Department of Medicine, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - Rufaida H Khan
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Québec, Canada.,Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Sadjia Bekal
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Québec, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Erwin Schurr
- Program in Infectious Diseases and Global Health, The Research Institute of the McGill University Health Centre and McGill International TB Centre, Department of Medicine, Faculty of Medicine, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - T Martin Schmeing
- Department of Biochemistry, Faculty of Medicine, McGill University, Montréal, Québec, Canada.,Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Samantha Gruenheid
- McGill Research Centre on Complex Traits and Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
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11
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Girgis S, Xu Z, Oikonomopoulos S, Fedorova AD, Tchesnokov EP, Gordon CJ, Schmeing TM, Götte M, Sonenberg N, Baranov PV, Ragoussis J, Hobman TC, Pelletier J. Evolution of naturally arising SARS-CoV-2 defective interfering particles. Commun Biol 2022; 5:1140. [PMID: 36302891 PMCID: PMC9610340 DOI: 10.1038/s42003-022-04058-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/30/2022] [Indexed: 11/23/2022] Open
Abstract
Defective interfering (DI) particles arise during virus propagation, are conditional on parental virus for replication and packaging, and interfere with viral expansion. There is much interest in developing DIs as anti-viral agents. Here we characterize DI particles that arose following serial passaging of SARS-CoV-2 at high multiplicity of infection. The prominent DIs identified have lost ~84% of the SARS-CoV-2 genome and are capable of attenuating parental viral titers. Synthetic variants of the DI genomes also interfere with infection and can be used as conditional, gene delivery vehicles. In addition, the DI genomes encode an Nsp1-10 fusion protein capable of attenuating viral replication. These results identify naturally selected defective viral genomes that emerged and stably propagated in the presence of parental virus. Genomes from defective interfering (DI) particles following serial passaging of SARS-CoV-2 reveal a fusion protein that attenuates viral replication. Synthetic, recombinant DI genomes are designed to interfere with SARS-CoV-2 replication.
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Affiliation(s)
- Samer Girgis
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Zaikun Xu
- Department of Cell Biology, U Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Spyros Oikonomopoulos
- McGill Genome Centre, Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Alla D Fedorova
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.,SFI Centre for Research Training in Genomics Data Science, University College Cork, Cork, Ireland
| | - Egor P Tchesnokov
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Calvin J Gordon
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Matthias Götte
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada.,Rosalind and Morris Goodman Cancer Institute, Montreal, QC, H3A 1A3, Canada
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Jiannis Ragoussis
- McGill Genome Centre, Department of Human Genetics, McGill University, Montreal, QC, Canada.,Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Tom C Hobman
- Department of Cell Biology, U Alberta, Edmonton, AB, T6G 2H7, Canada. .,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada. .,Li Ka Shing Institute of Virology, U Alberta, Edmonton, AB, T6G 2E1, Canada. .,Women & Children's Health Research Institute, U Alberta, Edmonton, AB, T6G 1C9, Canada.
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada. .,Rosalind and Morris Goodman Cancer Institute, Montreal, QC, H3A 1A3, Canada. .,Department of Oncology, McGill University, Montreal, QC, H3A 1G5, Canada.
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12
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Patteson JB, Fortinez CM, Putz AT, Rodriguez-Rivas J, Bryant LH, Adhikari K, Weigt M, Schmeing TM, Li B. Structure and Function of a Dehydrating Condensation Domain in Nonribosomal Peptide Biosynthesis. J Am Chem Soc 2022; 144:14057-14070. [PMID: 35895935 DOI: 10.1021/jacs.1c13404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehydroamino acids are important structural motifs and biosynthetic intermediates for natural products. Many bioactive natural products of nonribosomal origin contain dehydroamino acids; however, the biosynthesis of dehydroamino acids in most nonribosomal peptides is not well understood. Here, we provide biochemical and bioinformatic evidence in support of the role of a unique class of condensation domains in dehydration (CmodAA). We also obtain the crystal structure of a CmodAA domain, which is part of the nonribosomal peptide synthetase AmbE in the biosynthesis of the antibiotic methoxyvinylglycine. Biochemical analysis reveals that AmbE-CmodAA modifies a peptide substrate that is attached to the donor carrier protein. Mutational studies of AmbE-CmodAA identify several key residues for activity, including four residues that are mostly conserved in the CmodAA subfamily. Alanine mutation of these conserved residues either significantly increases or decreases AmbE activity. AmbE exhibits a dimeric conformation, which is uncommon and could enable transfer of an intermediate between different protomers. Our discovery highlights a central dehydrating function for CmodAA domains that unifies dehydroamino acid biosynthesis in diverse nonribosomal peptide pathways. Our work also begins to shed light on the mechanism of CmodAA domains. Understanding CmodAA domain function may facilitate identification of new natural products that contain dehydroamino acids and enable engineering of dehydroamino acids into nonribosomal peptides.
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Affiliation(s)
- Jon B Patteson
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Camille Marie Fortinez
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Andrew T Putz
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Juan Rodriguez-Rivas
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Biologie Computationnelle et Quantitative - LCQB, Paris 75005, France
| | - L Henry Bryant
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kamal Adhikari
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Martin Weigt
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Biologie Computationnelle et Quantitative - LCQB, Paris 75005, France
| | - T Martin Schmeing
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Bo Li
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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13
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Sharon I, Grogg M, Hilvert D, Schmeing TM. The structure of cyanophycinase in complex with a cyanophycin degradation intermediate. Biochim Biophys Acta Gen Subj 2022; 1866:130217. [PMID: 35905922 DOI: 10.1016/j.bbagen.2022.130217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/07/2022] [Accepted: 07/22/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cyanophycinases are serine protease family enzymes which are required for the metabolism of cyanophycin, the natural polymer multi-L-arginyl-poly(L-aspartic acid). Cyanophycinases degrade cyanophycin to β-Asp-Arg dipeptides, which enables use of this important store of fixed nitrogen. METHODS We used genetic code expansion to incorporate diaminopropionic acid into cyanophycinase in place of the active site serine, and determined a high-resolution structure of the covalent acyl-enzyme intermediate resulting from attack of cyanophycinase on a short cyanophycin segment. RESULTS The structure indicates that cyanophycin dipeptide residues P1 and P1' bind shallow pockets adjacent to the catalytic residues. We observe many cyanophycinase - P1 dipeptide interactions in the co-complex structure. Calorimetry measurements show that at least two cyanophycin dipeptides are needed for high affinity binding to cyanophycinase. We also characterized a putative cyanophycinase which we found to be structurally very similar but that shows no activity and could not be activated by mutation of its active site. GENERAL SIGNIFICANCE Despite its peptidic structure, cyanophycin is resistant to degradation by peptidases and other proteases. Our results help show how cyanophycinase can specifically bind and degrade this important polymer.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Marcel Grogg
- Laboratory of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - T Martin Schmeing
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada.
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14
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Abstract
Cyanophycin is a biopolymer composed of long chains of β-Asp-Arg. It is widespread in nature, being synthesized by many clades of bacteria, which use it as a cellular reservoir of nitrogen, carbon, and energy. Two enzymes are known to produce cyanophycin: cyanophycin synthetase 1 (CphA1), which builds cyanophycin from the amino acids Asp and Arg by alternating between two separate reactions for backbone extension and side chain modification, and cyanophycin synthetase 2 (CphA2), which polymerizes β-Asp-Arg dipeptides. CphA2 is evolutionarily related to CphA1, but questions about CphA2's altered structure and function remain unresolved. Cyanophycin and related molecules have drawn interest as green biopolymers. Because it only has a single active site, CphA2 could be more useful than CphA1 for biotechnological applications seeking to produce modified cyanophycin. In this study, we report biochemical assays on nine cyanobacterial CphA2 enzymes and report the crystal structure of CphA2 from Gloeothece citriformis at 3.0 Å resolution. The structure reveals a homodimeric, three-domain architecture. One domain harbors the polymerization active site and the two other domains have structural roles. The structure and biochemical assays explain how CphA2 binds and polymerizes β-Asp-Arg and highlights differences in in vitro oligomerization and activity between CphA2 enzymes. Using the structure and distinct activity profile as a guide, we introduced a single point mutation that converted Gloeothece citriformis CphA2 from a primer-dependent enzyme into a primer-independent enzyme.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal H3G 0B1, Quebec, Canada
| | - Marcel Grogg
- Laboratory of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - T. Martin Schmeing
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal H3G 0B1, Quebec, Canada
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15
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Fortinez CM, Bloudoff K, Harrigan C, Sharon I, Strauss M, Schmeing TM. Structures and function of a tailoring oxidase in complex with a nonribosomal peptide synthetase module. Nat Commun 2022; 13:548. [PMID: 35087027 PMCID: PMC8795117 DOI: 10.1038/s41467-022-28221-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/19/2021] [Indexed: 12/15/2022] Open
Abstract
Nonribosomal peptide synthetases (NRPSs) are large modular enzymes that synthesize secondary metabolites and natural product therapeutics. Most NRPS biosynthetic pathways include an NRPS and additional proteins that introduce chemical modifications before, during or after assembly-line synthesis. The bacillamide biosynthetic pathway is a common, three-protein system, with a decarboxylase that prepares an NRPS substrate, an NRPS, and an oxidase. Here, the pathway is reconstituted in vitro. The oxidase is shown to perform dehydrogenation of the thiazoline in the peptide intermediate while it is covalently attached to the NRPS, as the penultimate step in bacillamide D synthesis. Structural analysis of the oxidase reveals a dimeric, two-lobed architecture with a remnant RiPP recognition element and a dramatic wrapping loop. The oxidase forms a stable complex with the NRPS and dimerizes it. We visualized co-complexes of the oxidase bound to the elongation module of the NRPS using X-ray crystallography and cryo-EM. The three active sites (for adenylation, condensation/cyclization, and oxidation) form an elegant arc to facilitate substrate delivery. The structures enabled a proof-of-principle bioengineering experiment in which the BmdC oxidase domain is embedded into the NRPS.
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Affiliation(s)
- Camille Marie Fortinez
- Department of Biochemistry, McGill University, Montréal, QC, H3G 0B1, Canada.,Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada
| | - Kristjan Bloudoff
- Department of Biochemistry, McGill University, Montréal, QC, H3G 0B1, Canada.,Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada
| | - Connor Harrigan
- Department of Biochemistry, McGill University, Montréal, QC, H3G 0B1, Canada.,Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada
| | - Itai Sharon
- Department of Biochemistry, McGill University, Montréal, QC, H3G 0B1, Canada.,Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada
| | - Mike Strauss
- Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada.,Department of Anatomy and Cell Biology, McGill University, Montréal, QC, H3A 0C7, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QC, H3G 0B1, Canada. .,Centre de recherche en biologie structurale, McGill University, Montréal, QC, H3G 0B1, Canada.
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16
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Sullivan JR, Lupien A, Kalthoff E, Hamela C, Taylor L, Munro KA, Schmeing TM, Kremer L, Behr MA. Efficacy of epetraborole against Mycobacterium abscessus is increased with norvaline. PLoS Pathog 2021; 17:e1009965. [PMID: 34637487 PMCID: PMC8535176 DOI: 10.1371/journal.ppat.1009965] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 10/22/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022] Open
Abstract
Mycobacterium abscessus is the most common rapidly growing non-tuberculous mycobacteria to cause pulmonary disease in patients with impaired lung function such as cystic fibrosis. M. abscessus displays high intrinsic resistance to common antibiotics and inducible resistance to macrolides like clarithromycin. As such, M. abscessus is clinically resistant to the entire regimen of front-line M. tuberculosis drugs, and treatment with antibiotics that do inhibit M. abscessus in the lab results in cure rates of 50% or less. Here, we identified epetraborole (EPT) from the MMV pandemic response box as an inhibitor against the essential protein leucyl-tRNA synthetase (LeuRS) in M. abscessus. EPT protected zebrafish from lethal M. abscessus infection and did not induce self-resistance nor against clarithromycin. Contrary to most antimycobacterials, the whole-cell activity of EPT was greater against M. abscessus than M. tuberculosis, but crystallographic and equilibrium binding data showed that EPT binds LeuRSMabs and LeuRSMtb with similar residues and dissociation constants. Since EPT-resistant M. abscessus mutants lost LeuRS editing activity, these mutants became susceptible to misaminoacylation with leucine mimics like the non-proteinogenic amino acid norvaline. Proteomic analysis revealed that when M. abscessus LeuRS mutants were fed norvaline, leucine residues in proteins were replaced by norvaline, inducing the unfolded protein response with temporal changes in expression of GroEL chaperonins and Clp proteases. This supports our in vitro data that supplementation of media with norvaline reduced the emergence of EPT mutants in both M. abscessus and M. tuberculosis. Furthermore, the combination of EPT and norvaline had improved in vivo efficacy compared to EPT in a murine model of M. abscessus infection. Our results emphasize the effectiveness of EPT against the clinically relevant cystic fibrosis pathogen M. abscessus, and these findings also suggest norvaline adjunct therapy with EPT could be beneficial for M. abscessus and other mycobacterial infections like tuberculosis. Current antimycobacterial drugs are inadequate to handle the increasing number of non-tuberculous mycobacteria infections that eclipse tuberculosis infections in many developed countries. Of particular importance for cystic fibrosis patients, Mycobacterium abscessus is notoriously difficult to treat where patients spend extended time on antibiotics with cure rates comparable to extreme drug resistant M. tuberculosis. Here, we identified epetraborole (EPT) with in vitro and in vivo activities against M. abscessus. We showed that EPT targets the editing domain of the leucyl-tRNA synthetase (LeuRS) and that escape mutants lost LeuRS editing activity, making these mutants susceptible to misaminoacylation with leucine mimics. Most importantly, combination therapy of EPT and norvaline limited the rate of EPT resistance in both M. abscessus and M. tuberculosis, and this was the first study to demonstrate improved in vivo efficacy of EPT and norvaline compared to EPT in a murine model of M. abscessus pulmonary infection. The demonstration of norvaline adjunct therapy with EPT for M. abscessus infections is promising for cystic fibrosis patients and could translate to other mycobacterial infections, such as tuberculosis.
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Affiliation(s)
- Jaryd R. Sullivan
- Department of Microbiology & Immunology, McGill University, Montréal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, Canada
- McGill International TB Centre, Montréal, Canada
| | - Andréanne Lupien
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, Canada
- McGill International TB Centre, Montréal, Canada
| | - Elias Kalthoff
- Department of Biochemistry, McGill University, Montréal, Canada
- Centre de Recherche en Biologie Structural, McGill University, Montréal, Canada
| | - Claire Hamela
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, Montpellier, France
| | - Lorne Taylor
- Clinical Proteomics Platform, Research Institute of the McGill University Health Centre, Montréal, Canada
| | - Kim A. Munro
- Department of Biochemistry, McGill University, Montréal, Canada
- Centre de Recherche en Biologie Structural, McGill University, Montréal, Canada
| | - T. Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, Canada
- Centre de Recherche en Biologie Structural, McGill University, Montréal, Canada
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, Montpellier, France
- INSERM, IRIM, Montpellier, France
| | - Marcel A. Behr
- Department of Microbiology & Immunology, McGill University, Montréal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, Canada
- McGill International TB Centre, Montréal, Canada
- Department of Medicine, McGill University Health Centre, Montréal, Canada
- * E-mail:
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17
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Gonçalves CC, Sharon I, Schmeing TM, Ramos CHI, Young JC. The chaperone HSPB1 prepares protein aggregates for resolubilization by HSP70. Sci Rep 2021; 11:17139. [PMID: 34429462 PMCID: PMC8384840 DOI: 10.1038/s41598-021-96518-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/11/2021] [Indexed: 01/22/2023] Open
Abstract
In human cells under stress conditions, misfolded polypeptides can form potentially cytotoxic insoluble aggregates. To eliminate aggregates, the HSP70 chaperone machinery extracts and resolubilizes polypeptides for triage to refolding or degradation. Yeast and bacterial chaperones of the small heat-shock protein (sHSP) family can bind substrates at early stages of misfolding, during the aggregation process. The co-aggregated sHSPs then facilitate downstream disaggregation by HSP70. Because it is unknown whether a human sHSP has this activity, we investigated the disaggregation role of human HSPB1. HSPB1 co-aggregated with unfolded protein substrates, firefly luciferase and mammalian lactate dehydrogenase. The co-aggregates formed with HSPB1 were smaller and more regularly shaped than those formed in its absence. Importantly, co-aggregation promoted the efficient disaggregation and refolding of the substrates, led by HSP70. HSPB1 itself was also extracted during disaggregation, and its homo-oligomerization ability was not required. Therefore, we propose that a human sHSP is an integral part of the chaperone network for protein disaggregation.
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Affiliation(s)
- Conrado C Gonçalves
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Room 900, Montreal, QC, H3G 1Y6, Canada
| | - Itai Sharon
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Room 457, Montreal, QC, H3G 0B1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Room 457, Montreal, QC, H3G 0B1, Canada
| | - Carlos H I Ramos
- Institute of Chemistry, University of Campinas (UNICAMP), Campinas, SP, 13083-970, Brazil
| | - Jason C Young
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Room 900, Montreal, QC, H3G 1Y6, Canada.
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18
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Sharon I, Haque AS, Grogg M, Lahiri I, Seebach D, Leschziner AE, Hilvert D, Schmeing TM. Structures and function of the amino acid polymerase cyanophycin synthetase. Nat Chem Biol 2021; 17:1101-1110. [PMID: 34385683 DOI: 10.1038/s41589-021-00854-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 07/08/2021] [Indexed: 12/13/2022]
Abstract
Cyanophycin is a natural biopolymer produced by a wide range of bacteria, consisting of a chain of poly-L-Asp residues with L-Arg residues attached to the β-carboxylate sidechains by isopeptide bonds. Cyanophycin is synthesized from ATP, aspartic acid and arginine by a homooligomeric enzyme called cyanophycin synthetase (CphA1). CphA1 has domains that are homologous to glutathione synthetases and muramyl ligases, but no other structural information has been available. Here, we present cryo-electron microscopy and X-ray crystallography structures of cyanophycin synthetases from three different bacteria, including cocomplex structures of CphA1 with ATP and cyanophycin polymer analogs at 2.6 Å resolution. These structures reveal two distinct tetrameric architectures, show the configuration of active sites and polymer-binding regions, indicate dynamic conformational changes and afford insight into catalytic mechanism. Accompanying biochemical interrogation of substrate binding sites, catalytic centers and oligomerization interfaces combine with the structures to provide a holistic understanding of cyanophycin biosynthesis.
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Affiliation(s)
- Itai Sharon
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - Asfarul S Haque
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - Marcel Grogg
- Laboratory of Organic Chemistry, ETH Zürich, Zürich, Switzerland
| | - Indrajit Lahiri
- Department of Cellular and Molecular Medicine, and Section of Molecular Biology, Division of Biological Sciences, University of California San Diego (UCSD), La Jolla, CA, USA
| | - Dieter Seebach
- Laboratory of Organic Chemistry, ETH Zürich, Zürich, Switzerland
| | - Andres E Leschziner
- Department of Cellular and Molecular Medicine, and Section of Molecular Biology, Division of Biological Sciences, University of California San Diego (UCSD), La Jolla, CA, USA
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, Zürich, Switzerland
| | - T Martin Schmeing
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada.
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19
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Pelletier J, Schmeing TM, Sonenberg N. The multifaceted eukaryotic cap structure. Wiley Interdiscip Rev RNA 2020; 12:e1636. [PMID: 33300197 DOI: 10.1002/wrna.1636] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/16/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022]
Abstract
The 5' cap structure is added onto RNA polymerase II transcripts soon after initiation of transcription and modulates several post-transcriptional regulatory events involved in RNA maturation. It is also required for stimulating translation initiation of many cytoplasmic mRNAs and serves to protect mRNAs from degradation. These functional properties of the cap are mediated by several cap binding proteins (CBPs) involved in nuclear and cytoplasmic gene expression steps. The role that CBPs play in gene regulation, as well as the biophysical nature by which they recognize the cap, is quite intricate. Differences in mechanisms of capping as well as nuances in cap recognition speak to the potential of targeting these processes for drug development. In this review, we focus on recent findings concerning the cap epitranscriptome, our understanding of cap binding by different CBPs, and explore therapeutic targeting of CBP-cap interaction. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Processing > Capping and 5' End Modifications Translation > Translation Mechanisms.
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Affiliation(s)
- Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Department of Oncology, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada.,Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
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20
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Alonzo DA, Schmeing TM. Biosynthesis of depsipeptides, or Depsi: The peptides with varied generations. Protein Sci 2020; 29:2316-2347. [PMID: 33073901 DOI: 10.1002/pro.3979] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022]
Abstract
Depsipeptides are compounds that contain both ester bonds and amide bonds. Important natural product depsipeptides include the piscicide antimycin, the K+ ionophores cereulide and valinomycin, the anticancer agent cryptophycin, and the antimicrobial kutzneride. Furthermore, database searches return hundreds of uncharacterized systems likely to produce novel depsipeptides. These compounds are made by specialized nonribosomal peptide synthetases (NRPSs). NRPSs are biosynthetic megaenzymes that use a module architecture and multi-step catalytic cycle to assemble monomer substrates into peptides, or in the case of specialized depsipeptide synthetases, depsipeptides. Two NRPS domains, the condensation domain and the thioesterase domain, catalyze ester bond formation, and ester bonds are introduced into depsipeptides in several different ways. The two most common occur during cyclization, in a reaction between a hydroxy-containing side chain and the C-terminal amino acid residue in a peptide intermediate, and during incorporation into the growing peptide chain of an α-hydroxy acyl moiety, recruited either by direct selection of an α-hydroxy acid substrate or by selection of an α-keto acid substrate that is reduced in situ. In this article, we discuss how and when these esters are introduced during depsipeptide synthesis, survey notable depsipeptide synthetases, and review insight into bacterial depsipeptide synthetases recently gained from structural studies.
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Affiliation(s)
- Diego A Alonzo
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
| | - T Martin Schmeing
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Quebec, Canada
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21
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Robert F, Cencic R, Cai R, Schmeing TM, Pelletier J. RNA-tethering assay and eIF4G:eIF4A obligate dimer design uncovers multiple eIF4F functional complexes. Nucleic Acids Res 2020; 48:8562-8575. [PMID: 32749456 PMCID: PMC7470955 DOI: 10.1093/nar/gkaa646] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/05/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic cellular mRNAs possess a 5′ cap structure (m7GpppN) which plays a critical role in translation initiation mediated by eukaryotic initiation factor (eIF) 4F. The heterotrimeric eIF4F complex possesses several activities imparted by its subunits that include cap recognition (by eIF4E), RNA unwinding (eIF4A), and factor/ribosome recruitment (eIF4G). Mammalian cells have paralogs of all three eIF4F subunits and it remains an open question as to whether these all can participate in the process of ribosome recruitment. To query the activities of the eIF4F subunits in translation initiation, we adopted an RNA-tethering assay in which select subunits are recruited to a specific address on a reporter mRNA template. We find that all eIF4F subunits can participate in the initiation process. Based on eIF4G:eIF4A structural information, we also designed obligate dimer pairs to probe the activity of all combinations of eIF4G and eIF4A paralogs. We demonstrate that both eIF4GI and eIF4GII can associate with either eIF4A1 or eIF4A2 to recruit ribosomes to mRNA templates. In combination with eIF4E and eIF4E3, our results indicate the presence of up to eight eIF4F complexes that can operate in translation initiation.
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Affiliation(s)
- Francis Robert
- Department of Biochemistry, McGill University, Montreal, Canada
| | - Regina Cencic
- Department of Biochemistry, McGill University, Montreal, Canada
| | - Renying Cai
- Department of Biochemistry, McGill University, Montreal, Canada
| | | | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Canada.,Department of Oncology.,Rosalind & Morris Goodman Cancer Research Centre, McGill University, Montreal, Canada
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22
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Reimer JM, Eivaskhani M, Harb I, Guarné A, Weigt M, Schmeing TM. Structures of a dimodular nonribosomal peptide synthetase reveal conformational flexibility. Science 2020; 366:366/6466/eaaw4388. [PMID: 31699907 DOI: 10.1126/science.aaw4388] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 06/04/2019] [Accepted: 10/10/2019] [Indexed: 01/01/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) are biosynthetic enzymes that synthesize natural product therapeutics using a modular synthetic logic, whereby each module adds one aminoacyl substrate to the nascent peptide. We have determined five x-ray crystal structures of large constructs of the NRPS linear gramicidin synthetase, including a structure of a full core dimodule in conformations organized for the condensation reaction and intermodular peptidyl substrate delivery. The structures reveal differences in the relative positions of adjacent modules, which are not strictly coupled to the catalytic cycle and are consistent with small-angle x-ray scattering data. The structures and covariation analysis of homologs allowed us to create mutants that improve the yield of a peptide from a module-swapped dimodular NRPS.
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Affiliation(s)
- Janice M Reimer
- Department of Biochemistry and Center de Recherche en Biologie Structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Maximilian Eivaskhani
- Department of Biochemistry and Center de Recherche en Biologie Structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Ingrid Harb
- Department of Biochemistry and Center de Recherche en Biologie Structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Alba Guarné
- Department of Biochemistry and Center de Recherche en Biologie Structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Martin Weigt
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
| | - T Martin Schmeing
- Department of Biochemistry and Center de Recherche en Biologie Structurale, McGill University, Montréal, QC H3G 0B1, Canada.
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23
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Layoun A, Goldberg AA, Baig A, Eng M, Attias O, Nelson K, Carella A, Amberber N, Fielhaber JA, Joung KB, Schmeing TM, Han Y, Downey J, Divangahi M, Roux PP, Kristof AS. Regulation of protein kinase Cδ Nuclear Import and Apoptosis by Mechanistic Target of Rapamycin Complex-1. Sci Rep 2019; 9:17620. [PMID: 31772273 PMCID: PMC6879585 DOI: 10.1038/s41598-019-53909-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
Inactivation of the protein complex ‘mechanistic target of rapamycin complex 1’ (mTORC1) can increase the nuclear content of transcriptional regulators of metabolism and apoptosis. Previous studies established that nuclear import of signal transducer and activator of transcription-1 (STAT1) requires the mTORC1-associated adaptor karyopherin-α1 (KPNA1) when mTORC1 activity is reduced. However, the role of other mTORC1-interacting proteins in the complex, including ‘protein kinase C delta’ (PKCδ), have not been well characterized. In this study, we demonstrate that PKCδ, a STAT1 kinase, contains a functional ‘target of rapamycin signaling’ (TOS) motif that directs its interaction with mTORC1. Depletion of KPNA1 by RNAi prevented the nuclear import of PKCδ in cells exposed to the mTORC1 inhibitor rapamycin or amino acid restriction. Mutation of the TOS motif in PKCδ led to its loss of regulation by mTORC1 or karyopherin-α1, resulting in increased constitutive nuclear content. In cells expressing wild-type PKCδ, STAT1 activity and apoptosis were increased by rapamycin or interferon-β. Those expressing the PKCδ TOS mutant exhibited increased STAT1 activity and apoptosis; further enhancement by rapamycin or interferon-β, however, was lost. Therefore, the TOS motif in PKCδ is a novel structural mechanism by which mTORC1 prevents PKCδ and STAT1 nuclear import, and apoptosis.
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Affiliation(s)
- Antonio Layoun
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Alexander A Goldberg
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Ayesha Baig
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Mikaela Eng
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Ortal Attias
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Kristoff Nelson
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Alexandra Carella
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Nahomi Amberber
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Jill A Fielhaber
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Kwang-Bo Joung
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 0B1, Canada
| | - Yingshan Han
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Jeffrey Downey
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, EM3.2219, Montréal, Québec, H4A 3J1, Canada
| | - Maziar Divangahi
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, EM3.2219, Montréal, Québec, H4A 3J1, Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer, Faculty of Medicine, University of Montreal, P.O. Box 6128, Station Centre-Ville, Montréal, Québec, H3C 2J7, Canada
| | - Arnold S Kristof
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada.
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Tarry MJ, Harmel C, Taylor JA, Marczynski GT, Schmeing TM. Structures of GapR reveal a central channel which could accommodate B-DNA. Sci Rep 2019; 9:16679. [PMID: 31723182 PMCID: PMC6853979 DOI: 10.1038/s41598-019-52964-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/25/2019] [Indexed: 12/04/2022] Open
Abstract
GapR is a nucleoid-associated protein required for the cell cycle of Caulobacter cresentus. We have determined new crystal structures of GapR to high resolution. As in a recently published structure, a GapR monomer folds into one long N-terminal α helix and two shorter α helices, and assembles into a tetrameric ring with a closed, positively charged, central channel. In contrast to the conclusions drawn from the published structures, we observe that the central channel of the tetramer presented here could freely accommodate B-DNA. Mutation of six conserved lysine residues lining the cavity and electrophoretic mobility gel shift experiments confirmed their role in DNA binding and the channel as the site of DNA binding. Although present in our crystals, DNA could not be observed in the electron density maps, suggesting that DNA binding is non-specific, which could be important for tetramer-ring translocation along the chromosome. In conjunction with previous GapR structures we propose a model for DNA binding and translocation that explains key published observations on GapR and its biological functions.
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Affiliation(s)
- Michael J Tarry
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - Christoph Harmel
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - James A Taylor
- Department of Microbiology and Immunology, McGill University, 3775 University Street, Montreal, QC, H3A 2B4, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth 15 Road, Ottawa, ON, K1H 8L1, Canada
| | - Gregory T Marczynski
- Department of Microbiology and Immunology, McGill University, 3775 University Street, Montreal, QC, H3A 2B4, Canada.
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada.
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25
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Schmeing TM. Peptide synthesis away from the central dogma. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319099689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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26
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Reimer JM, Harb I, Ovchinnikova OG, Jiang J, Whitfield C, Schmeing TM. Structural Insight into a Novel Formyltransferase and Evolution to a Nonribosomal Peptide Synthetase Tailoring Domain. ACS Chem Biol 2018; 13:3161-3172. [PMID: 30346688 DOI: 10.1021/acschembio.8b00739] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) increase the chemical diversity of their products by acquiring tailoring domains. Linear gramicidin synthetase starts with a tailoring formylation (F) domain, which likely originated from a sugar formyltransferase (FT) gene. Here, we present studies on an Anoxybacillus kamchatkensis sugar FT representative of the prehorizontal gene transfer FT. Gene cluster analysis reveals that this FT acts on a UDP-sugar in a novel pathway for synthesis of a 7-formamido derivative of CMP-pseudaminic acid. We recapitulate the pathway up to and including the formylation step in vitro, experimentally demonstrating the role of the FT. We also present X-ray crystal structures of the FT alone and with ligands, which unveil contrasts with other structurally characterized sugar FTs and show close structural similarity with the F domain. The structures reveal insights into the adaptations that were needed to co-opt and evolve a sugar FT into a functional and useful NRPS domain.
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Affiliation(s)
- Janice M. Reimer
- Department of Biochemistry, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Ingrid Harb
- Department of Biochemistry, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Olga G. Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Jessie Jiang
- Department of Biochemistry, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - T. Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, Québec H3G 0B1, Canada
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27
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Reimer JM, Haque AS, Tarry MJ, Schmeing TM. Piecing together nonribosomal peptide synthesis. Curr Opin Struct Biol 2018; 49:104-113. [DOI: 10.1016/j.sbi.2018.01.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/08/2018] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
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28
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Bloudoff K, Schmeing TM. Structural and functional aspects of the nonribosomal peptide synthetase condensation domain superfamily: discovery, dissection and diversity. Biochim Biophys Acta Proteins Proteom 2017; 1865:1587-1604. [PMID: 28526268 DOI: 10.1016/j.bbapap.2017.05.010] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/05/2017] [Accepted: 05/12/2017] [Indexed: 01/23/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) are incredible macromolecular machines that produce a wide range of biologically- and therapeutically-relevant molecules. During synthesis, peptide elongation is performed by the condensation (C) domain, as it catalyzes amide bond formation between the nascent peptide and the amino acid it adds to the chain. Since their discovery more than two decades ago, C domains have been subject to extensive biochemical, bioinformatic, mutagenic, and structural analyses. They are composed of two lobes, each with homology to chloramphenicol acetyltransferase, have two binding sites for their two peptidyl carrier protein-bound ligands, and have an active site with conserved motif HHxxxDG located between the two lobes. This review discusses some of the important insights into the structure, catalytic mechanism, specificity, and gatekeeping functions of C domains revealed since their discovery. In addition, C domains are the archetypal members of the C domain superfamily, which includes several other members that also function as NRPS domains. The other family members can replace the C domain in NRP synthesis, can work in concert with a C domain, or can fulfill diverse and novel functions. These domains include the epimerization (E) domain, the heterocyclization (Cy) domain, the ester-bond forming C domain, the fungal NRPS terminal C domain (CT), the β-lactam ring forming C domain, and the X domain. We also discuss structural and function insight into C, E, Cy, CT and X domains, to present a holistic overview of historical and current knowledge of the C domain superfamily. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Kristjan Bloudoff
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada.
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29
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Tarry MJ, Haque AS, Bui KH, Schmeing TM. X-Ray Crystallography and Electron Microscopy of Cross- and Multi-Module Nonribosomal Peptide Synthetase Proteins Reveal a Flexible Architecture. Structure 2017; 25:783-793.e4. [PMID: 28434915 DOI: 10.1016/j.str.2017.03.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/02/2017] [Accepted: 03/23/2017] [Indexed: 10/19/2022]
Abstract
Nonribosomal peptide synthetases (NRPS) are macromolecular machines that produce peptides with diverse activities. Structural information exists for domains, didomains, and even modules, but little is known about higher-order organization. We performed a multi-technique study on constructs from the dimodular NRPS DhbF. We determined a crystal structure of a cross-module construct including the adenylation (A) and peptidyl carrier protein (PCP) domains from module 1 and the condensation domain from module 2, complexed with an adenosine-vinylsulfonamide inhibitor and an MbtH-like protein (MLP). The action of the inhibitor and the role of the MLP were investigated using adenylation reactions and isothermal titration calorimetry. In the structure, the PCP and A domains adopt a novel conformation, and noncovalent, cross-module interactions are limited. We calculated envelopes of dimodular DhbF using negative-stain electron microscopy. The data show large conformational variability between modules. Together, our results suggest that NRPSs lack a uniform, rigid supermodular architecture.
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Affiliation(s)
- Michael J Tarry
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
| | - Asfarul S Haque
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada.
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Abstract
Environmental samples are excellent sources of natural products that possess numerous kinds of therapeutic activities. One important family of natural products is the nonribosomal peptides, which includes penicillin, cyclosporin, viomycin and daptomycin (Cubicin). These peptides are made in bacteria or fungi by large enzymes called nonribosomal peptide synthetases (NRPS). NRPSs are true macromolecular machines or nanofactories, with modular assembly-line logic, a complex catalytic cycle, moving parts and many active sites. Visualization of large fragments of NRPSs at various functional states is required to understand the manner in which NRPSs synthesize their important products. Many excellent structural experiments have been performed to date. Recently, we added to the structural knowledge by visualizing the first module of the NRPS, which makes linear gramicidin, a clinical topical antibiotic, in all its major functional states. These experiments show how the individual domains, including an unusual tailoring domain, function together in assembly-line synthesis. Along with the ever-expanding body of biophysical, biochemical and genetic work, this work brings us closer to a fundamental understanding of these natural antibiotic nanofactories, and perhaps the ability to exploit them to produce novel therapeutics.
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Reimer JM, Aloise MN, Powell HR, Schmeing TM. Manipulation of an existing crystal form unexpectedly results in interwoven packing networks with pseudo-translational symmetry. Acta Crystallogr D Struct Biol 2016; 72:1130-1136. [PMID: 27710934 PMCID: PMC5053139 DOI: 10.1107/s2059798316013504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 08/22/2016] [Indexed: 01/01/2023]
Abstract
A nonribosomal peptide synthetase di-domain construct was produced using known crystal packing as a guide, and the resulting crystal has an unanticipated packing. Nonribosomal peptide synthetases (NRPSs) are multimodular enzymes that synthesize a myriad of diverse molecules. Tailoring domains have been co-opted into NRPSs to introduce further variety into nonribosomal peptide products. Linear gramicidin synthetase contains a unique formylation-tailoring domain in its initiation module (F-A-PCP). The structure of the F-A di-domain has previously been determined in a crystal form which had large solvent channels and no density for the minor Asub subdomain. An attempt was made to take advantage of this packing by removing the Asub subdomain from the construct (F-AΔsub) in order to produce a crystal that could accommodate the PCP domain. In the resulting crystal the original packing network was still present, but a second network with the same packing and almost no contact with the original network took the place of the solvent channels and changed the space group of the crystal.
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Affiliation(s)
- Janice M Reimer
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, Quebec H3G 0B1, Canada
| | - Martin N Aloise
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, Quebec H3G 0B1, Canada
| | | | - T Martin Schmeing
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Montreal, Quebec H3G 0B1, Canada
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Argyropoulos P, Bergeret F, Pardin C, Reimer JM, Pinto A, Boddy CN, Schmeing TM. Towards a characterization of the structural determinants of specificity in the macrocyclizing thioesterase for deoxyerythronolide B biosynthesis. Biochim Biophys Acta Gen Subj 2016; 1860:486-97. [DOI: 10.1016/j.bbagen.2015.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 11/13/2015] [Accepted: 11/20/2015] [Indexed: 12/12/2022]
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Reimer JM, Aloise MN, Harrison PM, Schmeing TM. Synthetic cycle of the initiation module of a formylating nonribosomal peptide synthetase. Nature 2016; 529:239-42. [PMID: 26762462 DOI: 10.1038/nature16503] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/02/2015] [Indexed: 12/22/2022]
Abstract
Nonribosomal peptide synthetases (NRPSs) are very large proteins that produce small peptide molecules with wide-ranging biological activities, including environmentally friendly chemicals and many widely used therapeutics. NRPSs are macromolecular machines, with modular assembly-line logic, a complex catalytic cycle, moving parts and many active sites. In addition to the core domains required to link the substrates, they often include specialized tailoring domains, which introduce chemical modifications and allow the product to access a large expanse of chemical space. It is still unknown how the NRPS tailoring domains are structurally accommodated into megaenzymes or how they have adapted to function in nonribosomal peptide synthesis. Here we present a series of crystal structures of the initiation module of an antibiotic-producing NRPS, linear gramicidin synthetase. This module includes the specialized tailoring formylation domain, and states are captured that represent every major step of the assembly-line synthesis in the initiation module. The transitions between conformations are large in scale, with both the peptidyl carrier protein domain and the adenylation subdomain undergoing huge movements to transport substrate between distal active sites. The structures highlight the great versatility of NRPSs, as small domains repurpose and recycle their limited interfaces to interact with their various binding partners. Understanding tailoring domains is important if NRPSs are to be utilized in the production of novel therapeutics.
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Affiliation(s)
- Janice M Reimer
- Department of Biochemistry, McGill University, 3649 Promenade Sir-William-Osler, Montréal, Québec H3G 0B1, Canada
| | - Martin N Aloise
- Department of Biochemistry, McGill University, 3649 Promenade Sir-William-Osler, Montréal, Québec H3G 0B1, Canada
| | - Paul M Harrison
- Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montréal, Québec H3A 1B1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, 3649 Promenade Sir-William-Osler, Montréal, Québec H3G 0B1, Canada
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Abstract
Cereulide synthetase is a two-protein nonribosomal peptide synthetase system that produces a potent emetic toxin in virulent strains of Bacillus cereus. The toxin cereulide is a depsipeptide, as it consists of alternating aminoacyl and hydroxyacyl residues. The hydroxyacyl residues are derived from keto acid substrates, which cereulide synthetase selects and stereospecifically reduces with imbedded ketoreductase domains before incorporating them into the growing depsipeptide chain. We present an in vitro biochemical characterization of cereulide synthetase. We investigate the kinetics and side chain specificity of α-keto acid selection, evaluate the requirement of an MbtH-like protein for adenylation domain activity, assay the effectiveness of vinylsulfonamide inhibitors on ester-adding modules, perform NADPH turnover experiments and evaluate in vitro depsipeptide biosynthesis. This work also provides biochemical insight into depsipeptide-synthesizing nonribosomal peptide synthetases responsible for other bioactive molecules such as valinomycin, antimycin and kutzneride.
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Affiliation(s)
- Diego A. Alonzo
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
| | - Nathan A. Magarvey
- Department of Chemistry & Chemical Biology, McMaster University, M.G. DeGroote Institute for Infectious Disease Research, 1200 Main St. W, Hamilton, Ontario L8N 3Z5, Canada
| | - T. Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
- Groupe de Recherche Axé sur la Structure des Protéines (GRASP), McGill University, Montréal, QC H3G 0B1, Canada
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Tarry MJ, Schmeing TM. Specific disulfide cross-linking to constrict the mobile carrier domain of nonribosomal peptide synthetases. Protein Eng Des Sel 2015; 28:163-70. [PMID: 25713404 DOI: 10.1093/protein/gzv009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/03/2015] [Indexed: 01/03/2023] Open
Abstract
Nonribosomal peptide synthetases are large, multi-domain enzymes that produce peptide molecules with important biological activity such as antibiotic, antiviral, anti-tumor, siderophore and immunosuppressant action. The adenylation (A) domain catalyzes two reactions in the biosynthetic pathway. In the first reaction, it activates the substrate amino acid by adenylation and in the second reaction it transfers the amino acid onto the phosphopantetheine arm of the adjacent peptide carrier protein (PCP) domain. The conformation of the A domain differs significantly depending on which of these two reactions it is catalyzing. Recently, several structures of A-PCP di-domains have been solved using mechanism-based inhibitors to trap the PCP domain in the A domain active site. Here, we present an alternative strategy to stall the A-PCP di-domain, by engineering a disulfide bond between the native amino acid substrate and the A domain. Size exclusion studies showed a significant shift in apparent size when the mutant A-PCP was provided with cross-linking reagents, and this shift was reversible in the presence of high concentrations of reducing agent. The cross-linked protein crystallized readily in several of the conditions screened and the best crystals diffracted to ≈8 Å.
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Affiliation(s)
- Michael J Tarry
- Department of Biochemistry, McGill University, Montréal, QC, Canada H3G 0B1
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, QC, Canada H3G 0B1 Groupe de Recherche Axé sur la Structure des Protéines (GRASP), McGill University, Montréal, QC, Canada H3G 0B1
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36
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Cencic R, Miura H, Malina A, Robert F, Ethier S, Schmeing TM, Dostie J, Pelletier J. Protospacer adjacent motif (PAM)-distal sequences engage CRISPR Cas9 DNA target cleavage. PLoS One 2014; 9:e109213. [PMID: 25275497 PMCID: PMC4183563 DOI: 10.1371/journal.pone.0109213] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/26/2014] [Indexed: 12/26/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR)-associated enzyme Cas9 is an RNA-guided nuclease that has been widely adapted for genome editing in eukaryotic cells. However, the in vivo target specificity of Cas9 is poorly understood and most studies rely on in silico predictions to define the potential off-target editing spectrum. Using chromatin immunoprecipitation followed by sequencing (ChIP-seq), we delineate the genome-wide binding panorama of catalytically inactive Cas9 directed by two different single guide (sg) RNAs targeting the Trp53 locus. Cas9:sgRNA complexes are able to load onto multiple sites with short seed regions adjacent to 5′NGG3′ protospacer adjacent motifs (PAM). Yet among 43 ChIP-seq sites harboring seed regions analyzed for mutational status, we find editing only at the intended on-target locus and one off-target site. In vitro analysis of target site recognition revealed that interactions between the 5′ end of the guide and PAM-distal target sequences are necessary to efficiently engage Cas9 nucleolytic activity, providing an explanation for why off-target editing is significantly lower than expected from ChIP-seq data.
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Affiliation(s)
- Regina Cencic
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | - Hisashi Miura
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec, Canada
| | - Abba Malina
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | - Francis Robert
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | - Sylvain Ethier
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
| | | | - Josée Dostie
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Québec, Canada
- The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec, Canada
- Department of Oncology, McGill University, Montreal, Québec, Canada
- * E-mail:
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37
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Alonzo D, Reimer J, Magarvey N, Schmeing TM. Towards the structure of an unusual nonribosomal peptide synthetase. Acta Crystallogr A Found Adv 2014. [DOI: 10.1107/s2053273314095667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Cereulide synthetase (Ces) is a macromolecular machine that produces a toxin involved in severe and lethal food poisoning. Ces belongs to the nonribosomal peptide synthetase (NRPS) family protein, and as such, it employs an assembly line mechanism to generate its cereulide product. The assembly line for cereulide differs from the canonical NRPS pathway because it adds hydroxy acids instead of amino acids at half of the positions in the molecule. To achieve this, the megaenzyme selects alpha keto acids through specialized adenylation domains and then reduces them to hydroxy acids in embedded ketoreductase domains, before adding them to the growing depsipeptide. Several details on the structural features of this unusual NRPS remain unknown. Here we report a full biochemical characterization of this highly complex megaenzyme. We obtained the kinetic constants of each of its four adenylation domains and probed the side chain selectivity for its alpha keto acid – recognizing adenylation domains. Also, we report that the activating protein MbtH is not required for full activity of the assembly line. Finally, we show that each of the modules can be inhibited through mechanism-based inhibitors, which can restrain the conformational flexibility paving the way for structural studies by X-ray crystallography.
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38
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Bloudoff K, Schmeing TM. Crystallization and preliminary crystallographic analysis of the first condensation domain of viomycin synthetase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:412-5. [PMID: 23545648 DOI: 10.1107/s1744309113004004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/08/2013] [Indexed: 11/10/2022]
Abstract
Nonribosomal peptide synthetases (NRPSs) are large multimodular enzymes that synthesize important secondary metabolites such as antibiotics. NRPSs follow a modular synthetic logic whereby each successive amino-acid monomer is added to the peptide chain by successive multi-domain modules. The condensation domain catalyzes the central chemical event in the synthetic cycle, peptide-bond formation, and is present in every elongation module of the NRPS. Viomycin is an antituberculosis nonribosomal peptide that is synthesized by a series of four NRPS proteins and then modified by tailoring proteins. In order to study the mechanisms of peptide-bond formation in viomycin and in NRPSs in general, a structural study of the first condensation domain of the viomycin synthetase protein VioA (VioA-C1) was initiated. The gene for VioA-C1 was cloned from genomic DNA of Streptomyces vinaceus, expressed as an octahistidine-tagged construct and purified by column chromatography. VioA-C1 was crystallized using the sitting-drop vapor-diffusion method. X-ray diffraction data were collected on a rotating-anode source to 2.9 Å resolution. The data could be indexed in the orthorhombic space group P212121, with unit-cell parameters a = 46.165, b = 68.335, c = 146.423 Å. There is likely to be one monomer in the asymmetric unit, giving a solvent content of 49.2% and a Matthews coefficient (VM) of 2.42 Å(3) Da(-1). Structural determination is in progress.
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Affiliation(s)
- Kristjan Bloudoff
- Department of Biochemistry, McGill University, Montréal, QC H3G 0B1, Canada
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39
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Abstract
Protein synthesis requires several guanosine triphosphatase (GTPase) factors, including elongation factor Tu (EF-Tu), which delivers aminoacyl-transfer RNAs (tRNAs) to the ribosome. To understand how the ribosome triggers GTP hydrolysis in translational GTPases, we have determined the crystal structure of EF-Tu and aminoacyl-tRNA bound to the ribosome with a GTP analog, to 3.2 angstrom resolution. EF-Tu is in its active conformation, the switch I loop is ordered, and the catalytic histidine is coordinating the nucleophilic water in position for inline attack on the γ-phosphate of GTP. This activated conformation is due to a critical and conserved interaction of the histidine with A2662 of the sarcin-ricin loop of the 23S ribosomal RNA. The structure suggests a universal mechanism for GTPase activation and hydrolysis in translational GTPases on the ribosome.
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Affiliation(s)
| | | | - Ann C Kelley
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
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40
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Schmeing TM, Voorhees RM, Kelley AC, Gao YG, Murphy FV, Weir JR, Ramakrishnan V. The crystal structure of the ribosome bound to EF-Tu and aminoacyl-tRNA. Science 2009; 326:688-694. [PMID: 19833920 DOI: 10.1126/science.1179700] [Citation(s) in RCA: 375] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The ribosome selects a correct transfer RNA (tRNA) for each amino acid added to the polypeptide chain, as directed by messenger RNA. Aminoacyl-tRNA is delivered to the ribosome by elongation factor Tu (EF-Tu), which hydrolyzes guanosine triphosphate (GTP) and releases tRNA in response to codon recognition. The signaling pathway that leads to GTP hydrolysis upon codon recognition is critical to accurate decoding. Here we present the crystal structure of the ribosome complexed with EF-Tu and aminoacyl-tRNA, refined to 3.6 angstrom resolution. The structure reveals details of the tRNA distortion that allows aminoacyl-tRNA to interact simultaneously with the decoding center of the 30S subunit and EF-Tu at the factor binding site. A series of conformational changes in EF-Tu and aminoacyl-tRNA suggests a communication pathway between the decoding center and the guanosine triphosphatase center of EF-Tu.
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Affiliation(s)
| | | | - Ann C Kelley
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
| | - Yong-Gui Gao
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
| | - Frank V Murphy
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
| | - John R Weir
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge, UK, CB2 0QH
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Passmore LA, Schmeing TM, Maag D, Applefield DJ, Acker MG, Algire MA, Lorsch JR, Ramakrishnan V. The eukaryotic translation initiation factors eIF1 and eIF1A induce an open conformation of the 40S ribosome. Mol Cell 2007; 26:41-50. [PMID: 17434125 DOI: 10.1016/j.molcel.2007.03.018] [Citation(s) in RCA: 245] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 03/13/2007] [Accepted: 03/26/2007] [Indexed: 01/11/2023]
Abstract
Initiation of translation is the process by which initiator tRNA and the start codon of mRNA are positioned in the ribosomal P site. In eukaryotes, one of the first steps involves the binding of two small factors, eIF1 and eIF1A, to the small (40S) ribosomal subunit. This facilitates tRNA binding, allows scanning of mRNA, and maintains fidelity of start codon recognition. Using cryo-EM, we have obtained 3D reconstructions of 40S bound to both eIF1 and eIF1A, and with each factor alone. These structures reveal that together, eIF1 and eIF1A stabilize a conformational change that opens the mRNA binding channel. Biochemical data reveal that both factors accelerate the rate of ternary complex (eIF2*GTP*Met-tRNA(i)(Met)) binding to 40S but only eIF1A stabilizes this interaction. Our results suggest that eIF1 and eIF1A promote an open, scanning-competent preinitiation complex that closes upon start codon recognition and eIF1 release to stabilize ternary complex binding and clamp down on mRNA.
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Affiliation(s)
- Lori A Passmore
- MRC-Laboratory of Molecular Biology, Hills Road, Cambridge, UK
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Schmeing TM, Huang KS, Kitchen DE, Strobel SA, Steitz TA. Structural insights into the roles of water and the 2' hydroxyl of the P site tRNA in the peptidyl transferase reaction. Mol Cell 2005; 20:437-48. [PMID: 16285925 DOI: 10.1016/j.molcel.2005.09.006] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 08/19/2005] [Accepted: 09/06/2005] [Indexed: 11/22/2022]
Abstract
Peptide bond formation is catalyzed at the peptidyl transferase center (PTC) of the large ribosomal subunit. Crystal structures of the large ribosomal subunit of Haloarcula marismortui (Hma) complexed with several analogs that represent either the substrates or the transition state intermediate of the peptidyl transferase reaction show that this reaction proceeds through a tetrahedral intermediate with S chirality. The oxyanion of the tetrahedral intermediate interacts with a water molecule that is positioned by nucleotides A2637 (E. coli numbering, 2602) and (methyl)U2619(2584). There are no Mg2+ ions or monovalent metal ions observed in the PTC that could directly promote catalysis. The A76 2' hydroxyl of the peptidyl-tRNA is hydrogen bonded to the alpha-amino group and could facilitate peptide bond formation by substrate positioning and by acting as a proton shuttle between the alpha-amino group and the A76 3' hydroxyl of the peptidyl-tRNA.
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Affiliation(s)
- T Martin Schmeing
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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Schmeing TM, Huang KS, Strobel SA, Steitz TA. An induced-fit mechanism to promote peptide bond formation and exclude hydrolysis of peptidyl-tRNA. Nature 2005; 438:520-4. [PMID: 16306996 DOI: 10.1038/nature04152] [Citation(s) in RCA: 287] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Accepted: 08/23/2005] [Indexed: 11/09/2022]
Abstract
The large ribosomal subunit catalyses the reaction between the alpha-amino group of the aminoacyl-tRNA bound to the A site and the ester carbon of the peptidyl-tRNA bound to the P site, while preventing the nucleophilic attack of water on the ester, which would lead to unprogrammed deacylation of the peptidyl-tRNA. Here we describe three new structures of the large ribosomal subunit of Haloarcula marismortui (Hma) complexed with peptidyl transferase substrate analogues that reveal an induced-fit mechanism in which substrates and active-site residues reposition to allow the peptidyl transferase reaction. Proper binding of an aminoacyl-tRNA analogue to the A site induces specific movements of 23S rRNA nucleotides 2618-2620 (Escherichia coli numbering 2583-2585) and 2541(2506), thereby reorienting the ester group of the peptidyl-tRNA and making it accessible for attack. In the absence of the appropriate A-site substrate, the peptidyl transferase centre positions the ester link of the peptidyl-tRNA in a conformation that precludes the catalysed nucleophilic attack by water. Protein release factors may also function, in part, by inducing an active-site rearrangement similar to that produced by the A-site aminoacyl-tRNA, allowing the carbonyl group and water to be positioned for hydrolysis.
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Affiliation(s)
- T Martin Schmeing
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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44
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Abstract
During translation, tRNAs cycle through three binding sites on the ribosome: the A, the P, and the E sites. We have determined the structures of complexes between the Haloarcula marismortui large ribosomal subunit and two different E site substrates: a deacylated tRNA acceptor stem minihelix and a CCA-acceptor end. Both of these tRNA mimics contain analogs of adenosine 76, the component responsible for a large proportion of E site binding affinity. They bind in the center of the loop-extension of protein L44e, and make specific contacts with both L44e and 23S rRNA including bases that are conserved in all three kingdoms of life. These contacts are consistent with the footprinting, protection, and cross-linking data that have identified the E site biochemically. These structures explain the specificity of the E site for deacylated tRNAs, as it is too small to accommodate any relevant aminoacyl-tRNA. The orientation of the minihelix suggests that it may mimic the P/E hybrid state. It appears that the E site on the 50S subunit was formed by only RNA in the last common ancestor of the three kingdoms, since the proteins at the E sites of H. marismortui and Deinucoccus radiodurans large subunits are not homologous.
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Affiliation(s)
- T Martin Schmeing
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA
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45
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Hansen JL, Schmeing TM, Klein DJ, Ippolito JA, Ban N, Nissen P, Freeborn B, Moore PB, Steitz TA. Progress toward an understanding of the structure and enzymatic mechanism of the large ribosomal subunit. Cold Spring Harb Symp Quant Biol 2003; 66:33-42. [PMID: 12762006 DOI: 10.1101/sqb.2001.66.33] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- J L Hansen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
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46
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Abstract
The large ribosomal subunit catalyzes peptide bond formation and will do so by using small aminoacyl- and peptidyl-RNA fragments of tRNA. We have refined at 3-A resolution the structures of both A and P site substrate and product analogues, as well as an intermediate analogue, bound to the Haloarcula marismortui 50S ribosomal subunit. A P site substrate, CCA-Phe-caproic acid-biotin, binds equally to both sites, but in the presence of sparsomycin binds only to the P site. The CCA portions of these analogues are bound identically by either the A or P loop of the 23S rRNA. Combining the separate P and A site substrate complexes into one model reveals interactions that may occur when both are present simultaneously. The alpha-NH(2) group of an aminoacylated fragment in the A site forms one hydrogen bond with the N3 of A2486 (2451) and may form a second hydrogen bond either with the 2' OH of the A-76 ribose in the P site or with the 2' OH of A2486 (2451). These interactions position the alpha amino group adjacent to the carbonyl carbon of esterified P site substrate in an orientation suitable for a nucleophilic attack.
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Affiliation(s)
- Jeffrey L Hansen
- Department of Molecular Biophysics and Biochemistry, Yale University, 266 Whitney Avenue, New Haven, CT 06520-8114, USA
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Schmeing TM, Seila AC, Hansen JL, Freeborn B, Soukup JK, Scaringe SA, Strobel SA, Moore PB, Steitz TA. A pre-translocational intermediate in protein synthesis observed in crystals of enzymatically active 50S subunits. Nat Struct Biol 2002; 9:225-30. [PMID: 11828326 DOI: 10.1038/nsb758] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The large ribosomal subunit catalyzes peptide bond formation during protein synthesis. Its peptidyl transferase activity has often been studied using a 'fragment assay' that depends on high concentrations of methanol or ethanol. Here we describe a version of this assay that does not require alcohol and use it to show, both crystallographically and biochemically, that crystals of the large ribosomal subunits from Haloarcula marismortui are enzymatically active. Addition of these crystals to solutions containing substrates results in formation of products, which ceases when crystals are removed. When substrates are diffused into large subunit crystals, the subsequent structure shows that products have formed. The CC-puromycin-peptide product is found bound to the A-site and the deacylated CCA is bound to the P-site, with its 3prime prime or minute OH near N3 A2486 (Escherichia coli A2451). Thus, this structure represents a state that occurs after peptide bond formation but before the hybrid state of protein synthesis.
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Affiliation(s)
- T Martin Schmeing
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA
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