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Gan T, Liu Y, Qiao Y, Dong Y, Feng J, Chen X, Zhu L. Translation regulation in Bacillus subtilis and its applications in heterologous protein expression: A review. Int J Biol Macromol 2025; 311:143653. [PMID: 40311986 DOI: 10.1016/j.ijbiomac.2025.143653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2025] [Revised: 04/11/2025] [Accepted: 04/28/2025] [Indexed: 05/03/2025]
Abstract
Bacillus subtilis is widely used for industrial enzyme production due to its food safety and good capability of protein synthesis and secretion. However, the production of heterologous proteins is often inefficient, partly due to poor compatibility and versatility of genetic elements in B. subtilis. Recent study shows that transcription and translation is uncoupled in B. subtilis, which is quite different from general knowledge about the transcription-translation coupling mechanism in bacteria. The uncoupling mechanism in B. subtilis shows that the transcription rate is much faster than translation rate. Therefore, the translation regulation will play an important role in highly-effective synthesis of heterologous protein. To better understanding the different regulation strategies at the translation level in B. subtilis, this review will summarize the translation process in B. subtilis cell and its regulatory mechanisms as well as the differences in comparison to other bacteria. Besides, the genetic engineering strategies for engineering the translation regulatory elements are also summarized.
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Affiliation(s)
- Tian Gan
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yidi Liu
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Ying Qiao
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yangyang Dong
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiacheng Feng
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xiaolong Chen
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
| | - Linjiang Zhu
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou 310014, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
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2
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Tian Y, Li Q, Fatma S, Jiang J, Jin H, Zeng F, Huang RH. Molecular and structural basis of a subfamily of PrfH rescuing both the damaged and intact ribosomes stalled in translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.09.632186. [PMID: 39829893 PMCID: PMC11741408 DOI: 10.1101/2025.01.09.632186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/22/2025]
Abstract
In bacteria, spontaneous mRNAs degradation and ribotoxin-induced RNA damage are two main biological events that lead to the stall of protein translation. The ubiquitous trans-translation system as well as several alternative rescue factors (Arfs) are responsible for rescuing the stalled ribosomes caused by truncated mRNAs that lack the stop codons. To date, protein release factor homolog (PrfH) is the only factor known to rescue the stalled ribosome damaged by ribotoxins. Here we show that a subfamily of PrfH, exemplified by PrfH from Capnocytophaga gingivalis (CgPrfH), rescues both types of stalled ribosomes described above. Our in vitro biochemical assays demonstrate that CgPrfH hydrolyzes the peptides attached to P-site tRNAs when in complex with both the damaged and intact ribosomes. Two cryo-EM structures of CgPrfH in complex with the damaged and intact 70S ribosomes revealed that CgPrfH employs two different regions of the protein to recognize two different stalled ribosomes to orient the GGQ motif for peptide hydrolysis. Thus, using a combination of bioinformatic, biochemical, and structural characterization described here, we have uncovered a family of ribosome rescue factors that possesses dual activities to resolve two distinct stalled protein translation in bacteria.
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Affiliation(s)
- Yannan Tian
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- These authors contributed equally: Yannan Tian and Qingrong Li
| | - Qingrong Li
- Department of Systems Biology, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
- These authors contributed equally: Yannan Tian and Qingrong Li
| | - Shirin Fatma
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Junyi Jiang
- Department of Systems Biology, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Fuxing Zeng
- Department of Systems Biology, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, 518055, P.R. China
| | - Raven H. Huang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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3
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Wu Y, Ni MT, Wang YH, Wang C, Hou H, Zhang X, Zhou J. Structural basis of translation inhibition by a valine tRNA-derived fragment. Life Sci Alliance 2024; 7:e202302488. [PMID: 38599770 PMCID: PMC11009984 DOI: 10.26508/lsa.202302488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 03/22/2024] [Accepted: 03/22/2024] [Indexed: 04/12/2024] Open
Abstract
Translational regulation by non-coding RNAs is a mechanism commonly used by cells to fine-tune gene expression. A fragment derived from an archaeal valine tRNA (Val-tRF) has been previously identified to bind the small subunit of the ribosome and inhibit translation in Haloferax volcanii Here, we present three cryo-electron microscopy structures of Val-tRF bound to the small subunit of Sulfolobus acidocaldarius ribosomes at resolutions between 4.02 and 4.53 Å. Within these complexes, Val-tRF was observed to bind to conserved RNA-interacting sites, including the ribosomal decoding center. The binding of Val-tRF destabilizes helices h24, h44, and h45 and the anti-Shine-Dalgarno sequence of 16S rRNA. The binding position of this molecule partially overlaps with the translation initiation factor aIF1A and occludes the mRNA P-site codon. Moreover, we found that the binding of Val-tRF is associated with steric hindrance of the H69 base of 23S rRNA in the large ribosome subunit, thereby preventing 70S assembly. Our data exemplify how tRNA-derived fragments bind to ribosomes and provide new insights into the mechanisms underlying translation inhibition by Val-tRFs.
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Affiliation(s)
- Yun Wu
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Meng-Ting Ni
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Ying-Hui Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Chen Wang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai Hou
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an Shaanxi, China
| | - Xing Zhang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China
| | - Jie Zhou
- Life Sciences Institute, Zhejiang University, Hangzhou, China
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4
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Seely SM, Basu RS, Gagnon MG. Mechanistic insights into the alternative ribosome recycling by HflXr. Nucleic Acids Res 2024; 52:4053-4066. [PMID: 38407413 DOI: 10.1093/nar/gkae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/02/2024] [Accepted: 02/19/2024] [Indexed: 02/27/2024] Open
Abstract
During stress conditions such as heat shock and antibiotic exposure, ribosomes stall on messenger RNAs, leading to inhibition of protein synthesis. To remobilize ribosomes, bacteria use rescue factors such as HflXr, a homolog of the conserved housekeeping GTPase HflX that catalyzes the dissociation of translationally inactive ribosomes into individual subunits. Here we use time-resolved cryo-electron microscopy to elucidate the mechanism of ribosome recycling by Listeria monocytogenes HflXr. Within the 70S ribosome, HflXr displaces helix H69 of the 50S subunit and induces long-range movements of the platform domain of the 30S subunit, disrupting inter-subunit bridges B2b, B2c, B4, B7a and B7b. Our findings unveil a unique ribosome recycling strategy by HflXr which is distinct from that mediated by RRF and EF-G. The resemblance between HflXr and housekeeping HflX suggests that the alternative ribosome recycling mechanism reported here is universal in the prokaryotic kingdom.
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Affiliation(s)
- Savannah M Seely
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Ritwika S Basu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Matthieu G Gagnon
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
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5
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Teran D, Zhang Y, Korostelev AA. Endogenous trans-translation structure visualizes the decoding of the first tmRNA alanine codon. Front Microbiol 2024; 15:1369760. [PMID: 38500588 PMCID: PMC10944890 DOI: 10.3389/fmicb.2024.1369760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/19/2024] [Indexed: 03/20/2024] Open
Abstract
Ribosomes stall on truncated or otherwise damaged mRNAs. Bacteria rely on ribosome rescue mechanisms to replenish the pool of ribosomes available for translation. Trans-translation, the main ribosome-rescue pathway, uses a circular hybrid transfer-messenger RNA (tmRNA) to restart translation and label the resulting peptide for degradation. Previous studies have visualized how tmRNA and its helper protein SmpB interact with the stalled ribosome to establish a new open reading frame. As tmRNA presents the first alanine codon via a non-canonical mRNA path in the ribosome, the incoming alanyl-tRNA must rearrange the tmRNA molecule to read the codon. Here, we describe cryo-EM analyses of an endogenous Escherichia coli ribosome-tmRNA complex with tRNAAla accommodated in the A site. The flexible adenosine-rich tmRNA linker, which connects the mRNA-like domain with the codon, is stabilized by the minor groove of the canonically positioned anticodon stem of tRNAAla. This ribosome complex can also accommodate a tRNA near the E (exit) site, bringing insights into the translocation and dissociation of the tRNA that decoded the defective mRNA prior to tmRNA binding. Together, these structures uncover a key step of ribosome rescue, in which the ribosome starts translating the tmRNA reading frame.
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Affiliation(s)
| | | | - Andrei A. Korostelev
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, United States
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6
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Park EN, Mackens-Kiani T, Berhane R, Esser H, Erdenebat C, Burroughs AM, Berninghausen O, Aravind L, Beckmann R, Green R, Buskirk AR. B. subtilis MutS2 splits stalled ribosomes into subunits without mRNA cleavage. EMBO J 2024; 43:484-506. [PMID: 38177497 PMCID: PMC10897456 DOI: 10.1038/s44318-023-00010-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 01/06/2024] Open
Abstract
Stalled ribosomes are rescued by pathways that recycle the ribosome and target the nascent polypeptide for degradation. In E. coli, these pathways are triggered by ribosome collisions through the recruitment of SmrB, a nuclease that cleaves the mRNA. In B. subtilis, the related protein MutS2 was recently implicated in ribosome rescue. Here we show that MutS2 is recruited to collisions by its SMR and KOW domains, and we reveal the interaction of these domains with collided ribosomes by cryo-EM. Using a combination of in vivo and in vitro approaches, we show that MutS2 uses its ABC ATPase activity to split ribosomes, targeting the nascent peptide for degradation through the ribosome quality control pathway. However, unlike SmrB, which cleaves mRNA in E. coli, we see no evidence that MutS2 mediates mRNA cleavage or promotes ribosome rescue by tmRNA. These findings clarify the biochemical and cellular roles of MutS2 in ribosome rescue in B. subtilis and raise questions about how these pathways function differently in diverse bacteria.
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Affiliation(s)
- Esther N Park
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Timur Mackens-Kiani
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Rebekah Berhane
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hanna Esser
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Chimeg Erdenebat
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - A Maxwell Burroughs
- Computational Biology Branch, Intramural Research Program, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Otto Berninghausen
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - L Aravind
- Computational Biology Branch, Intramural Research Program, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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7
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Marathe N, Nguyen HA, Alumasa JN, Kuzmishin Nagy AB, Vazquez M, Dunham CM, Keiler KC. Antibiotic that inhibits trans-translation blocks binding of EF-Tu to tmRNA but not to tRNA. mBio 2023; 14:e0146123. [PMID: 37681945 PMCID: PMC10653918 DOI: 10.1128/mbio.01461-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 06/13/2023] [Indexed: 09/09/2023] Open
Abstract
IMPORTANCE Elongation factor thermo-unstable (EF-Tu) is a universally conserved translation factor that mediates productive interactions between tRNAs and the ribosome. In bacteria, EF-Tu also delivers transfer-messenger RNA (tmRNA)-SmpB to the ribosome during trans-translation. We report the first small molecule, KKL-55, that specifically inhibits EF-Tu activity in trans-translation without affecting its activity in normal translation. KKL-55 has broad-spectrum antibiotic activity, suggesting that compounds targeted to the tmRNA-binding interface of EF-Tu could be developed into new antibiotics to treat drug-resistant infections.
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Affiliation(s)
- Neeraja Marathe
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ha An Nguyen
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, Georgia, USA
| | - John N. Alumasa
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Alexandra B. Kuzmishin Nagy
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, Georgia, USA
| | - Michael Vazquez
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Christine M. Dunham
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, Georgia, USA
| | - Kenneth C. Keiler
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
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Park E, Mackens-Kiani T, Berhane R, Esser H, Erdenebat C, Burroughs AM, Berninghausen O, Aravind L, Beckmann R, Green R, Buskirk AR. B. subtilis MutS2 splits stalled ribosomes into subunits without mRNA cleavage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.05.539626. [PMID: 37205477 PMCID: PMC10187299 DOI: 10.1101/2023.05.05.539626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Stalled ribosomes are rescued by pathways that recycle the ribosome and target the nascent polypeptide for degradation. In E. coli, these pathways are triggered by ribosome collisions through recruitment of SmrB, a nuclease that cleaves the mRNA. In B. subtilis, the related protein MutS2 was recently implicated in ribosome rescue. Here we show that MutS2 is recruited to collisions by its SMR and KOW domains and reveal the interaction of these domains with collided ribosomes by cryo-EM. Using a combination of in vivo and in vitro approaches, we show that MutS2 uses its ABC ATPase activity to split ribosomes, targeting the nascent peptide for degradation by the ribosome quality control pathway. Notably, we see no evidence of mRNA cleavage by MutS2, nor does it promote ribosome rescue by tmRNA as SmrB cleavage does in E. coli. These findings clarify the biochemical and cellular roles of MutS2 in ribosome rescue in B. subtilis and raise questions about how these pathways function differently in various bacteria.
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Affiliation(s)
- Esther Park
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Timur Mackens-Kiani
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Rebekah Berhane
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hanna Esser
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Chimeg Erdenebat
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - A. Maxwell Burroughs
- Computational Biology Branch, Intramural Research Program, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Otto Berninghausen
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - L. Aravind
- Computational Biology Branch, Intramural Research Program, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R. Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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9
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D'Urso G, Guyomar C, Chat S, Giudice E, Gillet R. Insights into the ribosomal trans-translation rescue system: lessons from recent structural studies. FEBS J 2023; 290:1461-1472. [PMID: 35015931 DOI: 10.1111/febs.16349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/27/2021] [Accepted: 01/10/2022] [Indexed: 11/29/2022]
Abstract
The arrest of protein synthesis caused when ribosomes stall on an mRNA lacking a stop codon is a deadly risk for all cells. In bacteria, this situation is remedied by the trans-translation quality control system. Trans-translation occurs because of the synergistic action of two main partners, transfer-messenger RNA (tmRNA) and small protein B (SmpB). These act in complex to monitor protein synthesis, intervening when necessary to rescue stalled ribosomes. During this process, incomplete nascent peptides are tagged for destruction, problematic mRNAs are degraded and the previously stalled ribosomes are recycled. In this 'Structural Snapshot' article, we describe the mechanism at the molecular level, a view updated after the most recent structural studies using cryo-electron microscopy.
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Affiliation(s)
- Gaetano D'Urso
- Institut de Génétique et Développement de Rennes (IGDR), CNRS, Univ. Rennes, France
| | - Charlotte Guyomar
- Institut de Génétique et Développement de Rennes (IGDR), CNRS, Univ. Rennes, France
| | - Sophie Chat
- Institut de Génétique et Développement de Rennes (IGDR), CNRS, Univ. Rennes, France
| | - Emmanuel Giudice
- Institut de Génétique et Développement de Rennes (IGDR), CNRS, Univ. Rennes, France
| | - Reynald Gillet
- Institut de Génétique et Développement de Rennes (IGDR), CNRS, Univ. Rennes, France
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Srinivas P, Keiler KC, Dunham CM. Druggable differences: Targeting mechanistic differences between trans-translation and translation for selective antibiotic action. Bioessays 2022; 44:e2200046. [PMID: 35719031 PMCID: PMC9308750 DOI: 10.1002/bies.202200046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 02/03/2023]
Abstract
Bacteria use trans-translation to rescue stalled ribosomes and target incomplete proteins for proteolysis. Despite similarities between tRNAs and transfer-messenger RNA (tmRNA), the key molecule for trans-translation, new structural and biochemical data show important differences between translation and trans-translation at most steps of the pathways. tmRNA and its binding partner, SmpB, bind in the A site of the ribosome but do not trigger the same movements of nucleotides in the rRNA that are required for codon recognition by tRNA. tmRNA-SmpB moves from the A site to the P site of the ribosome without subunit rotation to generate hybrid states, and moves from the P site to a site outside the ribosome instead of to the E site. During catalysis, transpeptidation to tmRNA appears to require the ribosomal protein bL27, which is dispensable for translation, suggesting that this protein may be conserved in bacteria due to trans-translation. These differences provide insights into the fundamental nature of trans-translation, and provide targets for new antibiotics that may have decrease cross-reactivity with eukaryotic ribosomes.
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Affiliation(s)
- Pooja Srinivas
- Emory University School of Medicine, Department of Biochemistry, Atlanta, GA, USA
| | - Kenneth C. Keiler
- The Pennsylvania State University, Department of Biochemistry & Molecular Biology, University Park, PA, USA,Corresponding authors: Kenneth C. Keiler, , Christine M. Dunham,
| | - Christine M. Dunham
- Emory University School of Medicine, Department of Biochemistry, Atlanta, GA, USA,Corresponding authors: Kenneth C. Keiler, , Christine M. Dunham,
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11
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Tian Y, Zeng F, Raybarman A, Fatma S, Carruthers A, Li Q, Huang RH. Sequential rescue and repair of stalled and damaged ribosome by bacterial PrfH and RtcB. Proc Natl Acad Sci U S A 2022; 119:e2202464119. [PMID: 35858322 PMCID: PMC9304027 DOI: 10.1073/pnas.2202464119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/10/2022] [Indexed: 01/14/2023] Open
Abstract
RtcB is involved in transfer RNA (tRNA) splicing in archaeal and eukaryotic organisms. However, most RtcBs are found in bacteria, whose tRNAs have no introns. Because tRNAs are the substrates of archaeal and eukaryotic RtcB, it is assumed that bacterial RtcBs are for repair of damaged tRNAs. Here, we show that a subset of bacterial RtcB, denoted RtcB2 herein, specifically repair ribosomal damage in the decoding center. To access the damage site for repair, however, the damaged 70S ribosome needs to be dismantled first, and this is accomplished by bacterial PrfH. Peptide-release assays revealed that PrfH is only active with the damaged 70S ribosome but not with the intact one. A 2.55-Å cryo-electron microscopy structure of PrfH in complex with the damaged 70S ribosome provides molecular insight into PrfH discriminating between the damaged and the intact ribosomes via specific recognition of the cleaved 3'-terminal nucleotide. RNA repair assays demonstrated that RtcB2 efficiently repairs the damaged 30S ribosomal subunit but not the damaged tRNAs. Cell-based assays showed that the RtcB2-PrfH pair reverse the damage inflicted by ribosome-specific ribotoxins in vivo. Thus, our combined biochemical, structural, and cell-based studies have uncovered a bacterial defense system specifically evolved to reverse the lethal ribosomal damage in the decoding center for cell survival.
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Affiliation(s)
- Yannan Tian
- Department of Biochemistry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
| | - Fuxing Zeng
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, People’s Republic of China
| | - Adrika Raybarman
- Department of Biochemistry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
| | - Shirin Fatma
- Department of Biochemistry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
| | - Amy Carruthers
- Department of Biochemistry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
| | - Qingrong Li
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, People’s Republic of China
| | - Raven H. Huang
- Department of Biochemistry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
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12
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Identification and characterisation of sPEPs in Cryptococcus neoformans. Fungal Genet Biol 2022; 160:103688. [PMID: 35339703 DOI: 10.1016/j.fgb.2022.103688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/02/2022] [Accepted: 03/21/2022] [Indexed: 11/24/2022]
Abstract
Short open reading frame (sORF)-encoded peptides (sPEPs) have been found across a wide range of genomic locations in a variety of species. To date, their identification, validation, and characterisation in the human fungal pathogen Cryptococcus neoformans has been limited due to a lack of standardised protocols. We have developed an enrichment process that enables sPEP detection within a protein sample from this polysaccharide-encapsulated yeast, and implemented proteogenomics to provide insights into the validity of predicted and hypothetical sORFs annotated in the C. neoformans genome. Novel sORFs were discovered within the 5' and 3' UTRs of known transcripts as well as in "non-coding" RNAs. One novel candidate, dubbed NPB1, that resided in an RNA annotated as "non-coding", was chosen for characterisation. Through the creation of both specific point mutations and a full deletion allele, the function of the new sPEP, Npb1, was shown to resemble that of the bacterial trans-translation protein SmpB.
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13
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Ribosome collisions induce mRNA cleavage and ribosome rescue in bacteria. Nature 2022; 603:503-508. [PMID: 35264790 DOI: 10.1038/s41586-022-04416-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 01/07/2022] [Indexed: 01/17/2023]
Abstract
Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation1,2. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes3-6. Here, using a genetic screen in Escherichia coli, we discovered a new rescue factor that has endonuclease activity. SmrB cleaves mRNAs upstream of stalled ribosomes, allowing the ribosome rescue factor tmRNA (which acts on truncated mRNAs3) to rescue upstream ribosomes. SmrB is recruited to ribosomes and is activated by collisions. Cryo-electron microscopy structures of collided disomes from E. coli and Bacillus subtilis show distinct and conserved arrangements of individual ribosomes and the composite SmrB-binding site. These findings reveal the underlying mechanisms by which ribosome collisions trigger ribosome rescue in bacteria.
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14
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Kurita D, Himeno H. Bacterial Ribosome Rescue Systems. Microorganisms 2022; 10:372. [PMID: 35208827 PMCID: PMC8874680 DOI: 10.3390/microorganisms10020372] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 01/27/2022] [Accepted: 02/02/2022] [Indexed: 12/10/2022] Open
Abstract
To maintain proteostasis, the cell employs multiple ribosome rescue systems to relieve the stalled ribosome on problematic mRNA. One example of problematic mRNA is non-stop mRNA that lacks an in-frame stop codon produced by endonucleolytic cleavage or transcription error. In Escherichia coli, there are at least three ribosome rescue systems that deal with the ribosome stalled on non-stop mRNA. According to one estimation, 2-4% of translation is the target of ribosome rescue systems even under normal growth conditions. In the present review, we discuss the recent findings of ribosome rescue systems in bacteria.
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Affiliation(s)
| | - Hyouta Himeno
- Department of Biochemistry and Molecular Biology, Hirosaki University, 3, Bunkyo-cho, Hirosaki 036-8561, Japan;
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15
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Campos-Silva R, D’Urso G, Delalande O, Giudice E, Macedo AJ, Gillet R. Trans-Translation Is an Appealing Target for the Development of New Antimicrobial Compounds. Microorganisms 2021; 10:3. [PMID: 35056452 PMCID: PMC8778911 DOI: 10.3390/microorganisms10010003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/09/2021] [Accepted: 12/16/2021] [Indexed: 01/06/2023] Open
Abstract
Because of the ever-increasing multidrug resistance in microorganisms, it is crucial that we find and develop new antibiotics, especially molecules with different targets and mechanisms of action than those of the antibiotics in use today. Translation is a fundamental process that uses a large portion of the cell's energy, and the ribosome is already the target of more than half of the antibiotics in clinical use. However, this process is highly regulated, and its quality control machinery is actively studied as a possible target for new inhibitors. In bacteria, ribosomal stalling is a frequent event that jeopardizes bacterial wellness, and the most severe form occurs when ribosomes stall at the 3'-end of mRNA molecules devoid of a stop codon. Trans-translation is the principal and most sophisticated quality control mechanism for solving this problem, which would otherwise result in inefficient or even toxic protein synthesis. It is based on the complex made by tmRNA and SmpB, and because trans-translation is absent in eukaryotes, but necessary for bacterial fitness or survival, it is an exciting and realistic target for new antibiotics. Here, we describe the current and future prospects for developing what we hope will be a novel generation of trans-translation inhibitors.
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Affiliation(s)
- Rodrigo Campos-Silva
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90610-000, Brazil;
| | - Gaetano D’Urso
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Olivier Delalande
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Emmanuel Giudice
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Alexandre José Macedo
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90610-000, Brazil;
| | - Reynald Gillet
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
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16
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Nadler F, Lavdovskaia E, Richter-Dennerlein R. Maintaining mitochondrial ribosome function: The role of ribosome rescue and recycling factors. RNA Biol 2021; 19:117-131. [PMID: 34923906 PMCID: PMC8786322 DOI: 10.1080/15476286.2021.2015561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The universally conserved process of protein biosynthesis is crucial for maintaining cellular homoeostasis and in eukaryotes, mitochondrial translation is essential for aerobic energy production. Mitochondrial ribosomes (mitoribosomes) are highly specialized to synthesize 13 core subunits of the oxidative phosphorylation (OXPHOS) complexes. Although the mitochondrial translation machinery traces its origin from a bacterial ancestor, it has acquired substantial differences within this endosymbiotic environment. The cycle of mitoribosome function proceeds through the conserved canonical steps of initiation, elongation, termination and mitoribosome recycling. However, when mitoribosomes operate in the context of limited translation factors or on aberrant mRNAs, they can become stalled and activation of rescue mechanisms is required. This review summarizes recent advances in the understanding of protein biosynthesis in mitochondria, focusing especially on the mechanistic and physiological details of translation termination, and mitoribosome recycling and rescue.
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Affiliation(s)
- Franziska Nadler
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany
| | - Elena Lavdovskaia
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
| | - Ricarda Richter-Dennerlein
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
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17
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Structures of tmRNA and SmpB as they transit through the ribosome. Nat Commun 2021; 12:4909. [PMID: 34389707 PMCID: PMC8363625 DOI: 10.1038/s41467-021-24881-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 07/13/2021] [Indexed: 01/01/2023] Open
Abstract
In bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), a hybrid RNA known to have both a tRNA-like and an mRNA-like domain. Here we present four cryo-EM structures of the ribosome during trans-translation at resolutions from 3.0 to 3.4 Å. These include the high-resolution structure of the whole pre-accommodated state, as well as structures of the accommodated state, the translocated state, and a translocation intermediate. Together, they shed light on the movements of the tmRNA-SmpB complex in the ribosome, from its delivery by the elongation factor EF-Tu to its passage through the ribosomal A and P sites after the opening of the B1 bridges. Additionally, we describe the interactions between the tmRNA-SmpB complex and the ribosome. These explain why the process does not interfere with canonical translation.
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18
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Antoine L, Bahena-Ceron R, Devi Bunwaree H, Gobry M, Loegler V, Romby P, Marzi S. RNA Modifications in Pathogenic Bacteria: Impact on Host Adaptation and Virulence. Genes (Basel) 2021; 12:1125. [PMID: 34440299 PMCID: PMC8394870 DOI: 10.3390/genes12081125] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 12/19/2022] Open
Abstract
RNA modifications are involved in numerous biological processes and are present in all RNA classes. These modifications can be constitutive or modulated in response to adaptive processes. RNA modifications play multiple functions since they can impact RNA base-pairings, recognition by proteins, decoding, as well as RNA structure and stability. However, their roles in stress, environmental adaptation and during infections caused by pathogenic bacteria have just started to be appreciated. With the development of modern technologies in mass spectrometry and deep sequencing, recent examples of modifications regulating host-pathogen interactions have been demonstrated. They show how RNA modifications can regulate immune responses, antibiotic resistance, expression of virulence genes, and bacterial persistence. Here, we illustrate some of these findings, and highlight the strategies used to characterize RNA modifications, and their potential for new therapeutic applications.
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Affiliation(s)
| | | | | | | | | | | | - Stefano Marzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, F-67000 Strasbourg, France; (L.A.); (R.B.-C.); (H.D.B.); (M.G.); (V.L.); (P.R.)
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19
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Zarechenskaia AS, Sergiev PV, Osterman IA. Quality Control Mechanisms in Bacterial Translation. Acta Naturae 2021; 13:32-44. [PMID: 34377554 PMCID: PMC8327144 DOI: 10.32607/actanaturae.11401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/15/2021] [Indexed: 12/24/2022] Open
Abstract
Ribosome stalling during translation significantly reduces cell viability, because cells have to spend resources on the synthesis of new ribosomes. Therefore, all bacteria have developed various mechanisms of ribosome rescue. Usually, the release of ribosomes is preceded by hydrolysis of the tRNA-peptide bond, but, in some cases, the ribosome can continue translation thanks to the activity of certain factors. This review describes the mechanisms of ribosome rescue thanks to trans-translation and the activity of the ArfA, ArfB, BrfA, ArfT, HflX, and RqcP/H factors, as well as continuation of translation via the action of EF-P, EF-4, and EttA. Despite the ability of some systems to duplicate each other, most of them have their unique functional role, related to the quality control of bacterial translation in certain abnormalities caused by mutations, stress cultivation conditions, or antibiotics.
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Affiliation(s)
- A. S. Zarechenskaia
- Lomonosov Moscow State University, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Moscow, 119992 Russia
| | - P. V. Sergiev
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 143028 Russia
- Lomonosov Moscow State University, Institute of functional genomics, Moscow, 119992 Russia
- Lomonosov Moscow State University, Department of Chemistry, Moscow, 119992 Russia
| | - I. A. Osterman
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 143028 Russia
- Lomonosov Moscow State University, Department of Chemistry, Moscow, 119992 Russia
- Sirius University of Science and Technology, Genetics and Life Sciences Research Center, Sochi, 354340 Russia
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20
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Müller C, Crowe-McAuliffe C, Wilson DN. Ribosome Rescue Pathways in Bacteria. Front Microbiol 2021; 12:652980. [PMID: 33815344 PMCID: PMC8012679 DOI: 10.3389/fmicb.2021.652980] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Ribosomes that become stalled on truncated or damaged mRNAs during protein synthesis must be rescued for the cell to survive. Bacteria have evolved a diverse array of rescue pathways to remove the stalled ribosomes from the aberrant mRNA and return them to the free pool of actively translating ribosomes. In addition, some of these pathways target the damaged mRNA and the incomplete nascent polypeptide chain for degradation. This review highlights the recent developments in our mechanistic understanding of bacterial ribosomal rescue systems, including drop-off, trans-translation mediated by transfer-messenger RNA and small protein B, ribosome rescue by the alternative rescue factors ArfA and ArfB, as well as Bacillus ribosome rescue factor A, an additional rescue system found in some Gram-positive bacteria, such as Bacillus subtilis. Finally, we discuss the recent findings of ribosome-associated quality control in particular bacterial lineages mediated by RqcH and RqcP. The importance of rescue pathways for bacterial survival suggests they may represent novel targets for the development of new antimicrobial agents against multi-drug resistant pathogenic bacteria.
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Affiliation(s)
| | | | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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21
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Bezrukov F, Prados J, Renzoni A, Panasenko OO. MazF toxin causes alterations in Staphylococcus aureus transcriptome, translatome and proteome that underlie bacterial dormancy. Nucleic Acids Res 2021; 49:2085-2101. [PMID: 33544858 PMCID: PMC7913683 DOI: 10.1093/nar/gkaa1292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/07/2020] [Accepted: 12/28/2020] [Indexed: 12/23/2022] Open
Abstract
Antibiotic resistance is a serious problem which may be caused by bacterial dormancy. It has been suggested that bacterial toxin-antitoxin systems induce dormancy. We analyzed the genome-wide role of Staphylococcus aureus endoribonuclease toxin MazF using RNA-Seq, Ribo-Seq and quantitative proteomics. We characterized changes in transcriptome, translatome and proteome caused by MazF, and proposed that MazF decreases translation directly by cleaving mRNAs, and indirectly, by decreasing translation factors and by promoting ribosome hibernation. Important pathways affected during the early stage of MazF induction were identified: MazF increases cell wall thickness and decreases cell division; MazF activates SsrA-system which rescues stalled ribosomes, appearing as a result of MazF mRNA cleavage. These pathways may be promising targets for new antibacterial drugs that prevent bacteria dormancy. Finally, we described the overall impact of MazF on S. aureus cell physiology, and propose one of the mechanisms by which MazF might regulate cellular changes leading to dormancy.
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Affiliation(s)
- Fedor Bezrukov
- Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
| | - Julien Prados
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Adriana Renzoni
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland.,Division of Infectious Diseases, Department of Medicine, Geneva University Hospitals and Medical School, Geneva 1211, Switzerland
| | - Olesya O Panasenko
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
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22
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Eshraghi M, Karunadharma PP, Blin J, Shahani N, Ricci EP, Michel A, Urban NT, Galli N, Sharma M, Ramírez-Jarquín UN, Florescu K, Hernandez J, Subramaniam S. Mutant Huntingtin stalls ribosomes and represses protein synthesis in a cellular model of Huntington disease. Nat Commun 2021; 12:1461. [PMID: 33674575 PMCID: PMC7935949 DOI: 10.1038/s41467-021-21637-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 01/29/2021] [Indexed: 02/08/2023] Open
Abstract
The polyglutamine expansion of huntingtin (mHTT) causes Huntington disease (HD) and neurodegeneration, but the mechanisms remain unclear. Here, we found that mHtt promotes ribosome stalling and suppresses protein synthesis in mouse HD striatal neuronal cells. Depletion of mHtt enhances protein synthesis and increases the speed of ribosomal translocation, while mHtt directly inhibits protein synthesis in vitro. Fmrp, a known regulator of ribosome stalling, is upregulated in HD, but its depletion has no discernible effect on protein synthesis or ribosome stalling in HD cells. We found interactions of ribosomal proteins and translating ribosomes with mHtt. High-resolution global ribosome footprint profiling (Ribo-Seq) and mRNA-Seq indicates a widespread shift in ribosome occupancy toward the 5' and 3' end and unique single-codon pauses on selected mRNA targets in HD cells, compared to controls. Thus, mHtt impedes ribosomal translocation during translation elongation, a mechanistic defect that can be exploited for HD therapeutics.
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Affiliation(s)
- Mehdi Eshraghi
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Pabalu P. Karunadharma
- grid.214007.00000000122199231The Scripps Research Institute, Genomic Core, Jupiter, FL USA
| | - Juliana Blin
- grid.462957.b0000 0004 0598 0706Laboratory of Biology and Cellular Modelling at Ecole Normale Supérieure of Lyon, RNA Metabolism in Immunity and Infection Lab, LBMC, Lyon, France
| | - Neelam Shahani
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Emiliano P. Ricci
- grid.462957.b0000 0004 0598 0706Laboratory of Biology and Cellular Modelling at Ecole Normale Supérieure of Lyon, RNA Metabolism in Immunity and Infection Lab, LBMC, Lyon, France
| | | | | | - Nicole Galli
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Manish Sharma
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Uri Nimrod Ramírez-Jarquín
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Katie Florescu
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Jennifer Hernandez
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
| | - Srinivasa Subramaniam
- grid.214007.00000000122199231The Scripps Research Institute, Department of Neuroscience, Jupiter, FL USA
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23
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Datta M, Pillai M, Modak MJ, Liiv A, Khaja FT, Hussain T, Remme J, Varshney U. A mutation in the ribosomal protein uS12 reveals novel functions of its universally conserved PNSA loop. Mol Microbiol 2021; 115:1292-1308. [PMID: 33368752 DOI: 10.1111/mmi.14675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/28/2022]
Abstract
The ribosomal protein uS12 is conserved across all domains of life. Recently, a heterozygous spontaneous mutation in human uS12 (corresponding to R49K mutation immediately downstream of the universally conserved 44 PNSA47 loop in Escherichia coli uS12) was identified for causing ribosomopathy, highlighting the importance of the PNSA loop. To investigate the effects of a similar mutation in the absence of any wild-type alleles, we mutated the rpsL gene (encoding uS12) in E. coli. Consistent with its pathology (in humans), we were unable to generate the R49K mutation in E. coli in the absence of a support plasmid. However, we were able to generate the L48K mutation in its immediate vicinity. The L48K mutation resulted in a cold sensitive phenotype and ribosome biogenesis defect in the strain. We show that the L48K mutation impacts the steps of initiation and elongation. Furthermore, the genetic interactions of the L48K mutation with RRF and Pth suggest a novel role of the PNSA loop in ribosome recycling. Our studies reveal new functions of the PNSA loop in uS12, which has so far been studied in the context of translation elongation.
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Affiliation(s)
- Madhurima Datta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Maalavika Pillai
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Mamata Jayant Modak
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Aivar Liiv
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Faisal Tarique Khaja
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Tanweer Hussain
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Jaanus Remme
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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24
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Carbone CE, Demo G, Madireddy R, Svidritskiy E, Korostelev AA. ArfB can displace mRNA to rescue stalled ribosomes. Nat Commun 2020; 11:5552. [PMID: 33144582 PMCID: PMC7641280 DOI: 10.1038/s41467-020-19370-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022] Open
Abstract
Ribosomes stalled during translation must be rescued to replenish the pool of translation-competent ribosomal subunits. Bacterial alternative rescue factor B (ArfB) releases nascent peptides from ribosomes stalled on mRNAs truncated at the A site, allowing ribosome recycling. Prior structural work revealed that ArfB recognizes such ribosomes by inserting its C-terminal α-helix into the vacant mRNA tunnel. In this work, we report that ArfB can efficiently recognize a wider range of mRNA substrates, including longer mRNAs that extend beyond the A-site codon. Single-particle cryo-EM unveils that ArfB employs two modes of function depending on the mRNA length. ArfB acts as a monomer to accommodate a shorter mRNA in the ribosomal A site. By contrast, longer mRNAs are displaced from the mRNA tunnel by more than 20 Å and are stabilized in the intersubunit space by dimeric ArfB. Uncovering distinct modes of ArfB function resolves conflicting biochemical and structural studies, and may lead to re-examination of other ribosome rescue pathways, whose functions depend on mRNA lengths.
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Affiliation(s)
- Christine E Carbone
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, Massachusetts, 01605, United States
| | - Gabriel Demo
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, Massachusetts, 01605, United States
- Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 625 00, Czech Republic
| | - Rohini Madireddy
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, Massachusetts, 01605, United States
- Medicago Inc., 7 Triangle drive, Durham, NC, 27713, USA
| | - Egor Svidritskiy
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, Massachusetts, 01605, United States.
- Sanofi, 49 New York Ave, Suite 3660, Framingham, MA, 01701, USA.
| | - Andrei A Korostelev
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, Massachusetts, 01605, United States.
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25
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Mechanism of ribosome shutdown by RsfS in Staphylococcus aureus revealed by integrative structural biology approach. Nat Commun 2020; 11:1656. [PMID: 32245971 PMCID: PMC7125091 DOI: 10.1038/s41467-020-15517-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/05/2020] [Indexed: 11/08/2022] Open
Abstract
For the sake of energy preservation, bacteria, upon transition to stationary phase, tone down their protein synthesis. This process is favored by the reversible binding of small stress-induced proteins to the ribosome to prevent unnecessary translation. One example is the conserved bacterial ribosome silencing factor (RsfS) that binds to uL14 protein onto the large ribosomal subunit and prevents its association with the small subunit. Here we describe the binding mode of Staphylococcus aureus RsfS to the large ribosomal subunit and present a 3.2 Å resolution cryo-EM reconstruction of the 50S-RsfS complex together with the crystal structure of uL14-RsfS complex solved at 2.3 Å resolution. The understanding of the detailed landscape of RsfS-uL14 interactions within the ribosome shed light on the mechanism of ribosome shutdown in the human pathogen S. aureus and might deliver a novel target for pharmacological drug development and treatment of bacterial infections.
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26
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Guyomar C, Thépaut M, Nonin-Lecomte S, Méreau A, Goude R, Gillet R. Reassembling green fluorescent protein for in vitro evaluation of trans-translation. Nucleic Acids Res 2020; 48:e22. [PMID: 31919515 PMCID: PMC7038980 DOI: 10.1093/nar/gkz1204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/11/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022] Open
Abstract
In order to discover new antibiotics with improved activity and selectivity, we created a reliable in vitro reporter system to detect trans-translation activity, the main mechanism for recycling ribosomes stalled on problematic messenger RNA (mRNA) in bacteria. This system is based on an engineered tmRNA variant that reassembles the green fluorescent protein (GFP) when trans-translation is active. Our system is adapted for high-throughput screening of chemical compounds by fluorescence.
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Affiliation(s)
- Charlotte Guyomar
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, Rennes, France
| | - Marion Thépaut
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, Rennes, France.,SATT Ouest-Valorisation, Rennes, France
| | | | - Agnès Méreau
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, Rennes, France
| | - Renan Goude
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, Rennes, France
| | - Reynald Gillet
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, Rennes, France
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27
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Abstract
Pyrazinamide (PZA) is a cornerstone antimicrobial drug used exclusively for the treatment of tuberculosis (TB). Due to its ability to shorten drug therapy by 3 months and reduce disease relapse rates, PZA is considered an irreplaceable component of standard first-line short-course therapy for drug-susceptible TB and second-line treatment regimens for multidrug-resistant TB. Despite over 60 years of research on PZA and its crucial role in current and future TB treatment regimens, the mode of action of this unique drug remains unclear. Defining the mode of action for PZA will open new avenues for rational design of novel therapeutic approaches for the treatment of TB. In this review, we discuss the four prevailing models for PZA action, recent developments in modulation of PZA susceptibility and resistance, and outlooks for future research and drug development.
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28
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Structural Bases for the Fitness Cost of the Antibiotic-Resistance and Lethal Mutations at Position 1408 of 16S rRNA. Molecules 2019; 25:molecules25010159. [PMID: 31906077 PMCID: PMC6983231 DOI: 10.3390/molecules25010159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/29/2019] [Accepted: 12/29/2019] [Indexed: 02/04/2023] Open
Abstract
To understand a structural basis for the fitness cost of the A1408G antibiotic-resistance mutation in the ribosomal A-site RNA, we have determined crystal structures of its A1408C and A1408U lethal mutants, and made comparison with previously solved structures of the wild type and the antibiotic-resistant mutant. The A-site RNA containing an asymmetric internal loop functions as a molecular switch to discriminate a single cognate tRNA from several near-cognate tRNAs by its conformational ON/OFF switching. Overall structures of the “off” states of the A1408C/U lethal mutants are very similar to those of the wild type and the A1408G antibiotic-resistant mutant. However, significant differences are found in local base stacking interactions including the functionally important A1492 and A1493 residues. In the wild type and the A1408G antibiotic-resistant mutant “off” states, both adenines are exposed to the solvent region. On the other hand, one of the corresponding adenines of the lethal A1408C/U mutants stay deeply inside their A-site helices by forming a purine-pyrimidine AoC or A-U base pair and is sandwiched between the upper and lower bases. Therefore, the ON/OFF switching might unfavorably occur in the lethal mutants compared to the wild type and the A1408G antibiotic-resistant mutant. It is probable that bacteria manage to acquire antibiotic resistance without losing the function of the A-site molecular switch by mutating the position 1408 only from A to G, but not to pyrimidine base C or U.
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29
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Abstract
RNA-binding proteins (RBPs) are central to most if not all cellular processes, dictating the fate of virtually all RNA molecules in the cell. Starting with pioneering work on ribosomal proteins, studies of bacterial RBPs have paved the way for molecular studies of RNA-protein interactions. Work over the years has identified major RBPs that act on cellular transcripts at the various stages of bacterial gene expression and that enable their integration into post-transcriptional networks that also comprise small non-coding RNAs. Bacterial RBP research has now entered a new era in which RNA sequencing-based methods permit mapping of RBP activity in a truly global manner in vivo. Moreover, the soaring interest in understudied members of host-associated microbiota and environmental communities is likely to unveil new RBPs and to greatly expand our knowledge of RNA-protein interactions in bacteria.
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Affiliation(s)
- Erik Holmqvist
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Würzburg, Germany. .,Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
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30
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Rae CD, Gordiyenko Y, Ramakrishnan V. How a circularized tmRNA moves through the ribosome. Science 2019; 363:740-744. [PMID: 30765567 DOI: 10.1126/science.aav9370] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 01/22/2019] [Indexed: 01/05/2023]
Abstract
During trans-translation, transfer-messenger RNA (tmRNA) and small protein B (SmpB) together rescue ribosomes stalled on a truncated mRNA and tag the nascent polypeptide for degradation. We used cryo-electron microscopy to determine the structures of three key states of the tmRNA-SmpB-ribosome complex during trans translation at resolutions of 3.7 to 4.4 angstroms. The results show how tmRNA and SmpB act specifically on stalled ribosomes and how the circularized complex moves through the ribosome, enabling translation to switch from the old defective message to the reading frame on tmRNA.
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Affiliation(s)
- Christopher D Rae
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, England, UK
| | - Yuliya Gordiyenko
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, England, UK
| | - V Ramakrishnan
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, England, UK.
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31
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Guyomar C, Gillet R. When transfer-messenger RNA scars reveal its ancient origins. Ann N Y Acad Sci 2019; 1447:80-87. [PMID: 30815901 DOI: 10.1111/nyas.14035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 12/12/2022]
Abstract
In bacteria, trans-translation is the primary quality control mechanism for rescuing ribosomes arrested during translation. This key process is universally conserved and plays a crucial role in the viability and virulence of all bacteria. It is performed by transfer-messenger RNA (tmRNA) and its protein partner small protein B (SmpB). Here, we show that tmRNA is a key molecule that could have given birth to modern protein synthesis. The traces of an ancient RNA world persist in the structure of modern tmRNA, suggesting its old origins. Therefore, since it has both tRNA and mRNA functions, tmRNA could be the missing link that allowed modern genetic code to be read by the ribosome.
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Affiliation(s)
- Charlotte Guyomar
- Université de Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F-35000, Rennes, France
| | - Reynald Gillet
- Université de Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F-35000, Rennes, France
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32
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Expression, purification and characterization of the full-length SmpB protein from Mycobacterium tuberculosis. Protein Expr Purif 2018; 151:9-17. [DOI: 10.1016/j.pep.2018.05.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/26/2018] [Accepted: 05/28/2018] [Indexed: 11/20/2022]
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33
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Chen RB, Zhang K, Zhang H, Gao CY, Li CL. Analysis of the antimicrobial mechanism of porcine beta defensin 2 against E. coli by electron microscopy and differentially expressed genes. Sci Rep 2018; 8:14711. [PMID: 30279556 PMCID: PMC6168601 DOI: 10.1038/s41598-018-32822-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 09/13/2018] [Indexed: 12/15/2022] Open
Abstract
Porcine beta defensin 2 (pBD2) is a cationic antimicrobial peptide with broad spectrum antibacterial activity, which makes it a potential alternative to antibiotics to prevent and cure diseases of pigs. However, development of pBD2 as an effective antibiotic agent requires molecular understanding of its functional mechanism against pathogens. In this study, we investigated the functional mechanism of pBD2 antibacterial activity. Escherichia coli was incubated with different pBD2 concentrations for different times. Electron microscopy was used to analyze the locations of pBD2 and its induced morphological changes in E. coli. Gene expression analysis was also performed to further understand the molecular changes of E. coli in response to pBD2 incubation. The results demonstrated that E. coli membranes were broken, holed, and wrinkled after treatment with pBD2, and pBD2 was located on the cell membranes and manly in the cytoplasm. Furthermore, 38 differentially expressed genes (DEGs) were detected, successfully sequenced and confirmed by quantitative real-time PCR (qRT-PCR). Most of the known functional DEGs were associated with DNA transcription and translation and located in the cytoplasm. Collectively, the results suggest that pBD2 could have multiple modes of action and the main mechanism for killing E. coli might be influence on DNA transcription and translation by targeting intracellular molecules after membrane damage, although transport and metabolism proteins were also affected.
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Affiliation(s)
- Rui-Bo Chen
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Kun Zhang
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Heng Zhang
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Chun-Yu Gao
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China
| | - Chun-Li Li
- Department of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou, 450002, Henan, The People's Republic of China.
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34
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Macé K, Demay F, Guyomar C, Georgeault S, Giudice E, Goude R, Trautwetter A, Ermel G, Blanco C, Gillet R. A Genetic Tool to Quantify trans-Translation Activity in Vivo. J Mol Biol 2017; 429:3617-3625. [PMID: 29031699 DOI: 10.1016/j.jmb.2017.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/29/2017] [Accepted: 10/08/2017] [Indexed: 11/17/2022]
Abstract
In bacteria, trans-translation is the main quality control mechanism for rescuing ribosomes arrested during translation. This key process is universally conserved and plays a critical role in the viability and virulence of many pathogens. We developed a reliable in vivo double-fluorescence reporter system for the simultaneous quantification of both trans-translation and the associated proteolysis activities in bacteria. The assay was validated using mutant bacteria lacking tmRNA, SmpB, and the ClpP protease. Both antisense tmRNA-binding RNA and a peptide mimicking the SmpB C-terminal tail proved to be potent inhibitors of trans-translation in vivo. The double-fluorescent reporter was also tested with KKL-35, an oxadiazole derivative that is supposed to be a promising trans-translation inhibitor, and it surprisingly turns out that trans-translation is not the only target of KKL-35 in vivo.
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Affiliation(s)
- Kevin Macé
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Fanny Demay
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Charlotte Guyomar
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Sylvie Georgeault
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Emmanuel Giudice
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Renan Goude
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Annie Trautwetter
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Gwennola Ermel
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Carlos Blanco
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France.
| | - Reynald Gillet
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France.
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35
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Yang J, Liu Y, Liu Z, Meng C, Lin D. Backbone and side-chain resonance assignments for the tmRNA-binding protein, SmpB, from Mycobacterium tuberculosis. BIOMOLECULAR NMR ASSIGNMENTS 2017; 11:175-179. [PMID: 28258549 DOI: 10.1007/s12104-017-9742-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/24/2017] [Indexed: 06/06/2023]
Abstract
Small protein B (SmpB) is an essential molecule in trans-translation which is a universal biological pathway for protein synthesis in bacteria. Trans-translation can release stalled ribosomes from defective mRNAs and target tag-protein fragments for degradation, and then restart protein synthesis. The SmpB-tmRNA complex coordinating with other components of the trans-translation system, plays vital roles in Mycobacterium tuberculosis under both stress conditions and non-replicating conditions. Thus, elucidation of molecular details and dynamic properties of the SmpB-tmRNA interaction is a crucial step towards effectively blocking trans-translation process to shorten the duration of tuberculosis treatment. Here, we report resonance assignments for 1H, 13C and 15N of M. tuberculosis SmpB (MtSmpB, spanning residues 4-133) protein determined by a suite of 2D/3D heteronuclear NMR experiments along with predicted the secondary structure.
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Affiliation(s)
- Juanjuan Yang
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Yindi Liu
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Zhao Liu
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Chun Meng
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Donghai Lin
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
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36
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Joazeiro CAP. Ribosomal Stalling During Translation: Providing Substrates for Ribosome-Associated Protein Quality Control. Annu Rev Cell Dev Biol 2017; 33:343-368. [PMID: 28715909 DOI: 10.1146/annurev-cellbio-111315-125249] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells of all organisms survey problems during translation elongation, which may happen as a consequence of mRNA aberrations, inefficient decoding, or other sources. In eukaryotes, ribosome-associated quality control (RQC) senses elongation-stalled ribosomes and promotes dissociation of ribosomal subunits. This so-called ribosomal rescue releases the mRNA for degradation and allows 40S subunits to be recycled for new rounds of translation. However, the nascent polypeptide chains remain linked to tRNA and associated with the rescued 60S subunits. As a final critical step in this pathway, the Ltn1/Listerin E3 ligase subunit of the RQC complex (RQCc) ubiquitylates the nascent chain, which promotes clearance of the 60S subunit while simultaneously marking the nascent chain for elimination. Here we review the ribosomal stalling and rescue steps upstream of the RQCc, where one witnesses intersection with cellular machineries implicated in translation elongation, translation termination, ribosomal subunit recycling, and mRNA quality control. We emphasize both recent progress and future directions in this area, as well as examples linking ribosomal rescue with the production of Ltn1-RQCc substrates.
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Affiliation(s)
- Claudio A P Joazeiro
- ZMBH, University of Heidelberg, 69120 Heidelberg, Germany; .,The Scripps Research Institute, La Jolla, California 92037
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37
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Huter P, Müller C, Arenz S, Beckert B, Wilson DN. Structural Basis for Ribosome Rescue in Bacteria. Trends Biochem Sci 2017. [PMID: 28629612 DOI: 10.1016/j.tibs.2017.05.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Ribosomes that translate mRNAs lacking stop codons become stalled at the 3' end of the mRNA. Recycling of these stalled ribosomes is essential for cell viability. In bacteria three ribosome rescue systems have been identified so far, with the most ubiquitous and best characterized being the trans-translation system mediated by transfer-messenger RNA (tmRNA) and small protein B (SmpB). The two additional rescue systems present in some bacteria employ alternative rescue factor (Arf) A and release factor (RF) 2 or ArfB. Recent structures have revealed how ArfA mediates ribosome rescue by recruiting the canonical termination factor RF2 to ribosomes stalled on truncated mRNAs. This now provides us with the opportunity to compare and contrast the available structures of all three bacterial ribosome rescue systems.
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Affiliation(s)
- Paul Huter
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Feodor-Lynenstr. 25, 81377 München, Germany
| | - Claudia Müller
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Feodor-Lynenstr. 25, 81377 München, Germany
| | - Stefan Arenz
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Feodor-Lynenstr. 25, 81377 München, Germany
| | - Bertrand Beckert
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Feodor-Lynenstr. 25, 81377 München, Germany; Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Daniel N Wilson
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Feodor-Lynenstr. 25, 81377 München, Germany; Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
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38
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Ferrin MA, Subramaniam AR. Kinetic modeling predicts a stimulatory role for ribosome collisions at elongation stall sites in bacteria. eLife 2017; 6. [PMID: 28498106 PMCID: PMC5446239 DOI: 10.7554/elife.23629] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 05/10/2017] [Indexed: 02/01/2023] Open
Abstract
Ribosome stalling on mRNAs can decrease protein expression. To decipher ribosome kinetics at stall sites, we induced ribosome stalling at specific codons by starving the bacterium Escherichia coli for the cognate amino acid. We measured protein synthesis rates from a reporter library of over 100 variants that encoded systematic perturbations of translation initiation rate, the number of stall sites, and the distance between stall sites. Our measurements are quantitatively inconsistent with two widely-used kinetic models for stalled ribosomes: ribosome traffic jams that block initiation, and abortive (premature) termination of stalled ribosomes. Rather, our measurements support a model in which collision with a trailing ribosome causes abortive termination of the stalled ribosome. In our computational analysis, ribosome collisions selectively stimulate abortive termination without fine-tuning of kinetic rate parameters at ribosome stall sites. We propose that ribosome collisions serve as a robust timer for translational quality control pathways to recognize stalled ribosomes.
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Affiliation(s)
- Michael A Ferrin
- Basic Sciences Division and Computational Biology Program of Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Arvind R Subramaniam
- Basic Sciences Division and Computational Biology Program of Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, United States
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39
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Demo G, Svidritskiy E, Madireddy R, Diaz-Avalos R, Grant T, Grigorieff N, Sousa D, Korostelev AA. Mechanism of ribosome rescue by ArfA and RF2. eLife 2017; 6. [PMID: 28300532 PMCID: PMC5378476 DOI: 10.7554/elife.23687] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 03/14/2017] [Indexed: 11/13/2022] Open
Abstract
ArfA rescues ribosomes stalled on truncated mRNAs by recruiting release factor RF2, which normally binds stop codons to catalyze peptide release. We report two 3.2 Å resolution cryo-EM structures – determined from a single sample – of the 70S ribosome with ArfA•RF2 in the A site. In both states, the ArfA C-terminus occupies the mRNA tunnel downstream of the A site. One state contains a compact inactive RF2 conformation. Ordering of the ArfA N-terminus in the second state rearranges RF2 into an extended conformation that docks the catalytic GGQ motif into the peptidyl-transferase center. Our work thus reveals the structural dynamics of ribosome rescue. The structures demonstrate how ArfA ‘senses’ the vacant mRNA tunnel and activates RF2 to mediate peptide release without a stop codon, allowing stalled ribosomes to be recycled. DOI:http://dx.doi.org/10.7554/eLife.23687.001
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Affiliation(s)
- Gabriel Demo
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
| | - Egor Svidritskiy
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
| | - Rohini Madireddy
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Ruben Diaz-Avalos
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Timothy Grant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nikolaus Grigorieff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Duncan Sousa
- Department of Biological Science, Florida State University, Tallahassee, United States
| | - Andrei A Korostelev
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States.,Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
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40
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Mraheil MA, Frantz R, Teubner L, Wendt H, Linne U, Wingerath J, Wirth T, Chakraborty T. Requirement of the RNA-binding protein SmpB during intracellular growth of Listeria monocytogenes. Int J Med Microbiol 2017; 307:166-173. [PMID: 28202229 DOI: 10.1016/j.ijmm.2017.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/24/2017] [Accepted: 01/30/2017] [Indexed: 10/20/2022] Open
Abstract
Bacterial trans-translation is the main quality control mechanism employed to relieve stalled ribosomes. Trans-translation is mediated by the small protein B (SmpB) and transfer-mRNA (tmRNA) ribonucleoprotein complex, which interacts with translational complexes stalled at the 3' end of non-stop mRNAs to release the stalled ribosomes thereby targeting the nascent polypeptides and truncated mRNAs for degradation. The trans-translation system exists with a few exceptions in all bacteria. In the present study, we assessed the contribution of SmpB to the growth and virulence of Listeria monocytogenes, a human intracellular food-borne pathogen that colonizes host tissues to cause severe invasive infections. A smpB knockout significantly decreased the intracellular growth rate of L. monocytogenes during infection of murine macrophages. In addition, the mutant strain was attenuated for virulence when examined with the Galleria mellonella larvae killing assay and the organ colonisation model of mice following infection. Proteomic analysis of whole cell extracts of ΔsmpB deletion mutant revealed elevated protein levels of several proteins involved in ribosome assembly and interaction with tRNA substrates. These included the elongation factor Tu [EF-Tu] which promotes the GTP-dependent binding of aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis as well as the CysK which is known to interact with bacterial toxins that cleave tRNA substrates. The data presented here shed light on the role of SmpB and trans-translation during intracellular growth of L. monocytogenes.
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Affiliation(s)
- Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany.
| | - Renate Frantz
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| | - Lisa Teubner
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| | - Heiko Wendt
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| | - Uwe Linne
- Department of Chemistry, and LOEWE-Center for Synthetic Microbiology Core Facility for Mass Spectrometry, Philipps-University Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Jessica Wingerath
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Thomas Wirth
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Trinad Chakraborty
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
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41
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Zeng F, Chen Y, Remis J, Shekhar M, Phillips JC, Tajkhorshid E, Jin H. Structural basis of co-translational quality control by ArfA and RF2 bound to ribosome. Nature 2017; 541:554-557. [PMID: 28077875 DOI: 10.1038/nature21053] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/14/2016] [Indexed: 01/26/2023]
Abstract
Quality control mechanisms intervene appropriately when defective translation events occur, in order to preserve the integrity of protein synthesis. Rescue of ribosomes translating on messenger RNAs that lack stop codons is one of the co-translational quality control pathways. In many bacteria, ArfA recognizes stalled ribosomes and recruits the release factor RF2, which catalyses the termination of protein synthesis. Although an induced-fit mechanism of nonstop mRNA surveillance mediated by ArfA and RF2 has been reported, the molecular interaction between ArfA and RF2 in the ribosome that is responsible for the mechanism is unknown. Here we report an electron cryo-microscopy structure of ArfA and RF2 in complex with the 70S ribosome bound to a nonstop mRNA. The structure, which is consistent with our kinetic and biochemical data, reveals the molecular interactions that enable ArfA to specifically recruit RF2, not RF1, into the ribosome and to enable RF2 to release the truncated protein product in this co-translational quality control pathway. The positively charged C-terminal domain of ArfA anchors in the mRNA entry channel of the ribosome. Furthermore, binding of ArfA and RF2 induces conformational changes in the ribosomal decoding centre that are similar to those seen in other protein-involved decoding processes. Specific interactions between residues in the N-terminal domain of ArfA and RF2 help RF2 to adopt a catalytically competent conformation for peptide release. Our findings provide a framework for understanding recognition of the translational state of the ribosome by new proteins, and expand our knowledge of the decoding potential of the ribosome.
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Affiliation(s)
- Fuxing Zeng
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yanbo Chen
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jonathan Remis
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500, USA
| | - Mrinal Shekhar
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - James C Phillips
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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42
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James NR, Brown A, Gordiyenko Y, Ramakrishnan V. Translational termination without a stop codon. Science 2016; 354:1437-1440. [PMID: 27934701 PMCID: PMC5351859 DOI: 10.1126/science.aai9127] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/17/2016] [Indexed: 11/02/2022]
Abstract
Ribosomes stall when they encounter the end of messenger RNA (mRNA) without an in-frame stop codon. In bacteria, these "nonstop" complexes can be rescued by alternative ribosome-rescue factor A (ArfA). We used electron cryomicroscopy to determine structures of ArfA bound to the ribosome with 3'-truncated mRNA, at resolutions ranging from 3.0 to 3.4 angstroms. ArfA binds within the ribosomal mRNA channel and substitutes for the absent stop codon in the A site by specifically recruiting release factor 2 (RF2), initially in a compact preaccommodated state. A similar conformation of RF2 may occur on stop codons, suggesting a general mechanism for release-factor-mediated translational termination in which a conformational switch leads to peptide release only when the appropriate signal is present in the A site.
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Affiliation(s)
- Nathan R James
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Alan Brown
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Yuliya Gordiyenko
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - V Ramakrishnan
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
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43
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Huter P, Müller C, Beckert B, Arenz S, Berninghausen O, Beckmann R, Wilson DN. Structural basis for ArfA-RF2-mediated translation termination on mRNAs lacking stop codons. Nature 2016; 541:546-549. [PMID: 27906161 DOI: 10.1038/nature20821] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 11/25/2016] [Indexed: 11/09/2022]
Abstract
In bacteria, ribosomes stalled on truncated mRNAs that lack a stop codon are rescued by the transfer-messenger RNA (tmRNA), alternative rescue factor A (ArfA) or ArfB systems. Although tmRNA-ribosome and ArfB-ribosome structures have been determined, how ArfA recognizes the presence of truncated mRNAs and recruits the canonical termination release factor RF2 to rescue the stalled ribosomes is unclear. Here we present a cryo-electron microscopy reconstruction of the Escherichia coli 70S ribosome stalled on a truncated mRNA in the presence of ArfA and RF2. The structure shows that the C terminus of ArfA binds within the mRNA entry channel on the small ribosomal subunit, and explains how ArfA distinguishes between ribosomes that bear truncated or full-length mRNAs. The N terminus of ArfA establishes several interactions with the decoding domain of RF2, and this finding illustrates how ArfA recruits RF2 to the stalled ribosome. Furthermore, ArfA is shown to stabilize a unique conformation of the switch loop of RF2, which mimics the canonical translation termination state by directing the catalytically important GGQ motif within domain 3 of RF2 towards the peptidyl-transferase centre of the ribosome. Thus, our structure reveals not only how ArfA recruits RF2 to the ribosome but also how it promotes an active conformation of RF2 to enable translation termination in the absence of a stop codon.
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Affiliation(s)
- Paul Huter
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Claudia Müller
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Bertrand Beckert
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.,Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany
| | - Stefan Arenz
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Otto Berninghausen
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Daniel N Wilson
- Gene Center, Department of Biochemistry and Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.,Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany
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44
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Mechanistic insights into the alternative translation termination by ArfA and RF2. Nature 2016; 541:550-553. [PMID: 27906160 DOI: 10.1038/nature20822] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 11/25/2016] [Indexed: 01/07/2023]
Abstract
During cellular translation of messenger RNAs by ribosomes, the translation apparatus sometimes pauses or stalls at the elongation and termination steps. With the exception of programmed stalling, which is usually used by cells for regulatory purposes, ribosomes stalled on mRNAs need to be terminated and recycled to maintain adequate translation capacity. Much ribosome stalling originates in aberrant mRNAs that lack a stop codon. Transcriptional errors, misprocessing of primary transcripts, and undesired mRNA cleavage all contribute to the formation of non-stop mRNAs. Ribosomes stalled at the 3' end of non-stop mRNAs do not undergo normal termination owing to the lack of specific stop-codon recognition by canonical peptide release factors at the A-site decoding centre. In bacteria, the transfer-messenger RNA (tmRNA)-SmpB-mediated trans-translation rescue system reroutes stalled ribosomes to the normal elongation cycle and translation termination. Two additional rescue systems, ArfA-RF2 (refs 13, 14, 15, 16) and ArfB (formerly known as YaeJ), are also present in many bacterial species, but their mechanisms are not fully understood. Here, using cryo-electron microscopy, we characterize the structure of the Escherichia coli 70S ribosome bound with ArfA, the release factor RF2, a short non-stop mRNA and a cognate P-site tRNA. The C-terminal loop of ArfA occupies the mRNA entry channel on the 30S subunit, whereas its N terminus is sandwiched between the decoding centre and the switch loop of RF2, leading to marked conformational changes in both the decoding centre and RF2. Despite the distinct conformation of RF2, its conserved catalytic GGQ motif is precisely positioned next to the CCA-end of the P-site tRNA. These data illustrate a stop-codon surrogate mechanism for ArfA in facilitating the termination of non-stop ribosomal complexes by RF2.
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45
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Schureck MA, Repack A, Miles SJ, Marquez J, Dunham CM. Mechanism of endonuclease cleavage by the HigB toxin. Nucleic Acids Res 2016; 44:7944-53. [PMID: 27378776 PMCID: PMC5027501 DOI: 10.1093/nar/gkw598] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/17/2016] [Accepted: 06/22/2016] [Indexed: 01/11/2023] Open
Abstract
Bacteria encode multiple type II toxin-antitoxin modules that cleave ribosome-bound mRNAs in response to stress. All ribosome-dependent toxin family members structurally characterized to date adopt similar microbial RNase architectures despite possessing low sequence identities. Therefore, determining which residues are catalytically important in this specialized RNase family has been a challenge in the field. Structural studies of RelE and YoeB toxins bound to the ribosome provided significant insights but biochemical experiments with RelE were required to clearly demonstrate which residues are critical for acid-base catalysis of mRNA cleavage. Here, we solved an X-ray crystal structure of the wild-type, ribosome-dependent toxin HigB bound to the ribosome revealing potential catalytic residues proximal to the mRNA substrate. Using cell-based and biochemical assays, we further determined that HigB residues His54, Asp90, Tyr91 and His92 are critical for activity in vivo, while HigB H54A and Y91A variants have the largest effect on mRNA cleavage in vitro Comparison of X-ray crystal structures of two catalytically inactive HigB variants with 70S-HigB bound structures reveal that HigB active site residues undergo conformational rearrangements likely required for recognition of its mRNA substrate. These data support the emerging concept that ribosome-dependent toxins have diverse modes of mRNA recognition.
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Affiliation(s)
- Marc A Schureck
- Emory University School of Medicine, Department of Biochemistry, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Adrienne Repack
- Emory University School of Medicine, Department of Biochemistry, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Stacey J Miles
- Emory University School of Medicine, Department of Biochemistry, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Jhomar Marquez
- Emory University School of Medicine, Department of Biochemistry, 1510 Clifton Road NE, Atlanta, GA 30322, USA
| | - Christine M Dunham
- Emory University School of Medicine, Department of Biochemistry, 1510 Clifton Road NE, Atlanta, GA 30322, USA
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46
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Nuss AM, Heroven AK, Dersch P. RNA Regulators: Formidable Modulators of Yersinia Virulence. Trends Microbiol 2016; 25:19-34. [PMID: 27651123 DOI: 10.1016/j.tim.2016.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 08/08/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
A large repertoire of RNA-based regulatory mechanisms, including a plethora of cis- and trans-acting noncoding RNAs (ncRNAs), sensory RNA elements, regulatory RNA-binding proteins, and RNA-degrading enzymes have been uncovered lately as key players in the regulation of metabolism, stress responses, and virulence of the genus Yersinia. Many of them are strictly controlled in response to fluctuating environmental conditions sensed during the course of the infection, and certain riboregulators have already been shown to be crucial for virulence. Some of them are highly conserved among the family Enterobacteriaceae, while others are genus-, species-, or strain-specific and could contribute to the difference in Yersinia pathogenicity. Importantly, the analysis of Yersinia riboregulators has not only uncovered crucial elements and regulatory mechanisms governing host-pathogen interactions, it also revealed exciting new venues for the design of novel anti-infectives.
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Affiliation(s)
- Aaron M Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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47
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Abstract
Enteric pathogens of the family Enterobacteriaceae colonize various niches within animals and humans in which they compete with intestinal commensals and are attacked by the host immune system. To survive these hostile environments they possess complex, multilayer regulatory networks that coordinate the control of virulence factors, host-adapted metabolic functions and stress resistance. An important part of these intricate control networks are RNA-based control systems that enable the pathogen to fine-tune its responses. Recent next-generation sequencing approaches revealed a large repertoire of conserved and species-specific riboregulators, including numerous cis- and trans-acting non-coding RNAs, sensory RNA elements (RNA thermometers, riboswitches), regulatory RNA-binding proteins and RNA degrading enzymes which regulate colonization factors, toxins, host defense processes and virulence-relevant physiological and metabolic processes. All of which are important cues for pathogens to sense and respond to fluctuating conditions during the infection. This review covers infection-relevant riboregulators of E. coli, Salmonella, Shigella and Yersinia, highlights their versatile regulatory mechanisms, complex target regulons and functions, and discusses emerging topics and future challenges to fully understand and exploit RNA-based control to combat bacterial infections.
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Affiliation(s)
- Ann Kathrin Heroven
- a Department of Molecular Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Aaron M Nuss
- a Department of Molecular Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Petra Dersch
- a Department of Molecular Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany
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48
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Simms CL, Thomas EN, Zaher HS. Ribosome-based quality control of mRNA and nascent peptides. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27193249 DOI: 10.1002/wrna.1366] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 11/06/2022]
Abstract
Quality control processes are widespread and play essential roles in detecting defective molecules and removing them in order to maintain organismal fitness. Aberrant messenger RNA (mRNA) molecules, unless properly managed, pose a significant hurdle to cellular proteostasis. Often mRNAs harbor premature stop codons, possess structures that present a block to the translational machinery, or lack stop codons entirely. In eukaryotes, the three cytoplasmic mRNA-surveillance processes, nonsense-mediated decay (NMD), no-go decay (NGD), and nonstop decay (NSD), evolved to cope with these aberrant mRNAs, respectively. Nonstop mRNAs and mRNAs that inhibit translation elongation are especially problematic as they sequester valuable ribosomes from the translating ribosome pool. As a result, in addition to RNA degradation, NSD and NGD are intimately coupled to ribosome rescue in all domains of life. Furthermore, protein products produced from all three classes of defective mRNAs are more likely to malfunction. It is not surprising then that these truncated nascent protein products are subject to degradation. Over the past few years, many studies have begun to document a central role for the ribosome in initiating the RNA and protein quality control processes. The ribosome appears to be responsible for recognizing the target mRNAs as well as for recruiting the factors required to carry out the processes of ribosome rescue and nascent protein decay. WIREs RNA 2017, 8:e1366. doi: 10.1002/wrna.1366 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Carrie L Simms
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Erica N Thomas
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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49
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Abstract
Structural centers of motion (pivot points) in the ribosome have recently been identified by measurement of conformational changes in rRNA resulting from EF-G GTP hydrolysis. This series of measurements is extended here to the ribosome's interactions with the cofactor EF-Tu. Four recent EF-Tu bound ribosome structures were compared to unbound structures. A total of 16 pivots were identified, of which 4 are unique to the EF-Tu interaction. Pivots in the GTPase associated center and the sarcin-ricin loop omitted previously, are found to be mobile in response to both EF-Tu and EF-G binding. Pivots in the intersubunit bridge rRNAs are found to be cofactor specific. Head swiveling motions in the small subunit are observed in the EF-Tu bound structures that were trapped post GTP hydrolysis. As in the case of pivots associated with EF-G, the additional pivots described here are associated with weak points in the rRNA structures such as non-canonical pairs and bulge loops. The combined set of pivots should be regarded as a minimal set. Only several states available to the ribosome have been presented in this work. Future, precise crystal structures in conjunction with experimental data will likely show additional functional pivoting elements in the rRNA.
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Affiliation(s)
- Maxim Paci
- a Department of Biology and Biochemistry , University of Houston , Houston , TX , USA
| | - George E Fox
- a Department of Biology and Biochemistry , University of Houston , Houston , TX , USA
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50
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Zeng F, Jin H. Peptide release promoted by methylated RF2 and ArfA in nonstop translation is achieved by an induced-fit mechanism. RNA (NEW YORK, N.Y.) 2016; 22:49-60. [PMID: 26554029 PMCID: PMC4691834 DOI: 10.1261/rna.053082.115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 10/01/2015] [Indexed: 05/27/2023]
Abstract
Here we report that the specificity of peptide release in the ribosome on a nonstop mRNA by ArfA and RF2 is achieved by an induced-fit mechanism. Using RF2 that is methylated on the glutamine of its GGQ motif (RF2(m)), we show that methylation substantially increases the rate of ArfA/RF2-catalyzed peptide release on a nonstop mRNA that does not occupy the ribosomal A site, but has only a modest effect on k(cat) by the same proteins on longer nonstop mRNAs occupying the A site of the mRNA channel in the ribosome. Our data suggest that enhancement in the kcat of peptide release by ArfA and RF2 under the cognate decoding condition is the result of favorable conformational changes in the nonstop complex. We demonstrate a shared mechanism between canonical and nonstop termination, supported by similarities in the kinetic mechanisms in antibiotic inhibition and methylation-correlated enhancement in the rate of peptide release. Despite these similarities, our data suggest that nonstop termination differs from canonical pathway in the downstream event of recycling.
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Affiliation(s)
- Fuxing Zeng
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hong Jin
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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