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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: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [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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Maviza TP, Zarechenskaia AS, Burmistrova NR, Tchoub AS, Dontsova OA, Sergiev PV, Osterman IA. RtcB2-PrfH Operon Protects E. coli ATCC25922 Strain from Colicin E3 Toxin. Int J Mol Sci 2022; 23:ijms23126453. [PMID: 35742896 PMCID: PMC9223846 DOI: 10.3390/ijms23126453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/28/2022] [Accepted: 06/07/2022] [Indexed: 02/01/2023] Open
Abstract
In the bid to survive and thrive in an environmental setting, bacterial species constantly interact and compete for resources and space in the microbial ecosystem. Thus, they have adapted to use various antibiotics and toxins to fight their rivals. Simultaneously, they have evolved an ability to withstand weapons that are directed against them. Several bacteria harbor colicinogenic plasmids which encode toxins that impair the translational apparatus. One of them, colicin E3 ribotoxin, mediates cleavage of the 16S rRNA in the decoding center of the ribosome. In order to thrive upon deployment of such ribotoxins, competing bacteria may have evolved counter-conflict mechanisms to prevent their demise. A recent study demonstrated the role of PrfH and the RtcB2 module in rescuing a damaged ribosome and the subsequent re-ligation of the cleaved 16S rRNA by colicin E3 in vitro. The rtcB2-prfH genes coexist as gene neighbors in an operon that is sporadically spread among different bacteria. In the current study, we report that the RtcB2-PrfH module confers resistance to colicin E3 toxicity in E. coli ATCC25922 cells in vivo. We demonstrated that the viability of E. coli ATCC25922 strain that is devoid of rtcB2 and prfH genes is impaired upon action of colicin E3, in contrast to the parental strain which has intact rtcB2 and prfH genes. Complementation of the rtcB2 and prfH gene knockout with a high copy number-plasmid (encoding either rtcB2 alone or both rtcB2-prfH operon) restored resistance to colicin E3. These results highlight a counter-conflict system that may have evolved to thwart colicin E3 activity.
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Affiliation(s)
- Tinashe P. Maviza
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; (T.P.M.); (A.S.Z.); (O.A.D.); (P.V.S.)
| | - Anastasiia S. Zarechenskaia
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; (T.P.M.); (A.S.Z.); (O.A.D.); (P.V.S.)
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
| | - Nadezhda R. Burmistrova
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
| | - Andrey S. Tchoub
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
| | - Olga A. Dontsova
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; (T.P.M.); (A.S.Z.); (O.A.D.); (P.V.S.)
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 119992, Russia
| | - Petr V. Sergiev
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; (T.P.M.); (A.S.Z.); (O.A.D.); (P.V.S.)
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
| | - Ilya A. Osterman
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; (T.P.M.); (A.S.Z.); (O.A.D.); (P.V.S.)
- Department of Chemistry, Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; (N.R.B.); (A.S.T.)
- Genetics and Life Sciences Research Center, Sirius University of Science and Technology, 1 Olympic Ave., Sochi 354340, Russia
- Correspondence:
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Balasanyants SM, Aleksandrova EV, Polikanov YS. The Role of Release Factors in the Hydrolysis of Ester Bond in Peptidyl-tRNA. BIOCHEMISTRY (MOSCOW) 2021; 86:1122-1127. [PMID: 34565315 DOI: 10.1134/s0006297921090078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Class I release factors (RFs) recognize stop codons in the sequences of mRNAs and are required for the hydrolysis of peptidyl-tRNA in the ribosomal P site during the final step of protein synthesis in bacteria, resulting in the release of a complete polypeptide chain from the ribosome. A key role in this process belongs to the highly conserved GGQ motif in RFs. Mutations in this motif can reduce the hydrolysis rate or even completely inhibit the reaction. Previously, it was hypothesized that the amino acid residues of GGQ (especially glutamine) are essential for the proper coordination of the water molecule for subsequent hydrolysis of the ester bond. However, available structures of the 70S ribosome termination complex do not allow unambiguous identification of the exact orientation of the carbonyl group in peptidyl-tRNA relative to the GGQ, as well as of the position of the catalytic water molecule in the peptidyl transferase center (PTC). This mini-review summarizes key facts and hypotheses on the role of GGQ in the catalysis of peptide release, as well as suggests and discusses future experiments aimed to produce high-quality structural data for deciphering the precise mechanism of RF-mediated catalysis.
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Affiliation(s)
- Samson M Balasanyants
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Elena V Aleksandrova
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yury S Polikanov
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
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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: 0.7] [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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The Origin and Evolution of Release Factors: Implications for Translation Termination, Ribosome Rescue, and Quality Control Pathways. Int J Mol Sci 2019; 20:ijms20081981. [PMID: 31018531 PMCID: PMC6514570 DOI: 10.3390/ijms20081981] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 01/26/2023] Open
Abstract
The evolution of release factors catalyzing the hydrolysis of the final peptidyl-tRNA bond and the release of the polypeptide from the ribosome has been a longstanding paradox. While the components of the translation apparatus are generally well-conserved across extant life, structurally unrelated release factor peptidyl hydrolases (RF-PHs) emerged in the stems of the bacterial and archaeo-eukaryotic lineages. We analyze the diversification of RF-PH domains within the broader evolutionary framework of the translation apparatus. Thus, we reconstruct the possible state of translation termination in the Last Universal Common Ancestor with possible tRNA-like terminators. Further, evolutionary trajectories of the several auxiliary release factors in ribosome quality control (RQC) and rescue pathways point to multiple independent solutions to this problem and frequent transfers between superkingdoms including the recently characterized ArfT, which is more widely distributed across life than previously appreciated. The eukaryotic RQC system was pieced together from components with disparate provenance, which include the long-sought-after Vms1/ANKZF1 RF-PH of bacterial origin. We also uncover an under-appreciated evolutionary driver of innovation in rescue pathways: effectors deployed in biological conflicts that target the ribosome. At least three rescue pathways (centered on the prfH/RFH, baeRF-1, and C12orf65 RF-PH domains), were likely innovated in response to such conflicts.
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Li J, Zhang C, Huang P, Kuru E, Forster-Benson ETC, Li T, Church GM. Dissecting limiting factors of the Protein synthesis Using Recombinant Elements (PURE) system. TRANSLATION (AUSTIN, TEX.) 2017; 5:e1327006. [PMID: 28702280 PMCID: PMC5501384 DOI: 10.1080/21690731.2017.1327006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/14/2017] [Accepted: 04/28/2017] [Indexed: 01/10/2023]
Abstract
Reconstituted cell-free protein synthesis systems such as the Protein synthesis Using Recombinant Elements (PURE) system give high-throughput and controlled access to in vitro protein synthesis. Here we show that compared with the commercial S30 crude extract based RTS 100 E. coli HY system, the PURE system has less mRNA degradation and produces up to ∼6-fold full-length proteins. However the majority of polypeptides PURE produces are partially translated or inactive since the signal from firefly luciferase (Fluc) translated in PURE is only ∼2/3rd of that measured using the RTS 100 E. coli HY S30 system. Both of the 2 batch systems suffer from low ribosome recycling efficiency when translating proteins from 82 kD to 224 kD. A systematic fed-batch analysis of PURE shows replenishment of 6 small molecule substrates individually or in combination before energy depletion increased Fluc protein yield by ∼1.5 to ∼2-fold, while creatine phosphate and magnesium have synergistic effects when added to the PURE system. Additionally, while adding EF-P to PURE reduced full-length protein translated, it increased the fraction of functional protein and reduced partially translated protein probably by slowing down the translation process. Finally, ArfA, rather than YaeJ or PrfH, helped reduce ribosome stalling when translating Fluc and improved system productivity in a template-dependent fashion.
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Affiliation(s)
- Jun Li
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Harvard Institute of Biologically Inspired Engineering, Boston, MA, USA
| | - Chi Zhang
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Poyi Huang
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Erkin Kuru
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | | | - Taibo Li
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Harvard Institute of Biologically Inspired Engineering, Boston, MA, USA
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Burroughs AM, Aravind L. RNA damage in biological conflicts and the diversity of responding RNA repair systems. Nucleic Acids Res 2016; 44:8525-8555. [PMID: 27536007 PMCID: PMC5062991 DOI: 10.1093/nar/gkw722] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/08/2016] [Indexed: 12/16/2022] Open
Abstract
RNA is targeted in biological conflicts by enzymatic toxins or effectors. A vast diversity of systems which repair or ‘heal’ this damage has only recently become apparent. Here, we summarize the known effectors, their modes of action, and RNA targets before surveying the diverse systems which counter this damage from a comparative genomics viewpoint. RNA-repair systems show a modular organization with extensive shuffling and displacement of the constituent domains; however, a general ‘syntax’ is strongly maintained whereby systems typically contain: a RNA ligase (either ATP-grasp or RtcB superfamilies), nucleotidyltransferases, enzymes modifying RNA-termini for ligation (phosphatases and kinases) or protection (methylases), and scaffold or cofactor proteins. We highlight poorly-understood or previously-uncharacterized repair systems and components, e.g. potential scaffolding cofactors (Rot/TROVE and SPFH/Band-7 modules) with their respective cognate non-coding RNAs (YRNAs and a novel tRNA-like molecule) and a novel nucleotidyltransferase associating with diverse ligases. These systems have been extensively disseminated by lateral transfer between distant prokaryotic and microbial eukaryotic lineages consistent with intense inter-organismal conflict. Components have also often been ‘institutionalized’ for non-conflict roles, e.g. in RNA-splicing and in RNAi systems (e.g. in kinetoplastids) which combine a distinct family of RNA-acting prim-pol domains with DICER-like proteins.
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Affiliation(s)
- A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Characterization of 3'-Phosphate RNA Ligase Paralogs RtcB1, RtcB2, and RtcB3 from Myxococcus xanthus Highlights DNA and RNA 5'-Phosphate Capping Activity of RtcB3. J Bacteriol 2015; 197:3616-24. [PMID: 26350128 DOI: 10.1128/jb.00631-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 08/28/2015] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Escherichia coli RtcB exemplifies a family of GTP-dependent RNA repair/splicing enzymes that join 3'-PO4 ends to 5'-OH ends via stable RtcB-(histidinyl-N)-GMP and transient RNA3'pp5'G intermediates. E. coli RtcB also transfers GMP to a DNA 3'-PO4 end to form a stable "capped" product, DNA3'pp5'G. RtcB homologs are found in a multitude of bacterial proteomes, and many bacteria have genes encoding two or more RtcB paralogs; an extreme example is Myxococcus xanthus, which has six RtcBs. In this study, we purified, characterized, and compared the biochemical activities of three M. xanthus RtcB paralogs. We found that M. xanthus RtcB1 resembles E. coli RtcB in its ability to perform intra- and intermolecular sealing of a HORNAp substrate and capping of a DNA 3'-PO4 end. M. xanthus RtcB2 can splice HORNAp but has 5-fold-lower RNA ligase specific activity than RtcB1. In contrast, M. xanthus RtcB3 is distinctively feeble at ligating the HORNAp substrate, although it readily caps a DNA 3'-PO4 end. The novelty of M. xanthus RtcB3 is its capacity to cap DNA and RNA 5'-PO4 ends to form GppDNA and GppRNA products, respectively. As such, RtcB3 joins a growing list of enzymes (including RNA 3'-phosphate cyclase RtcA and thermophilic ATP-dependent RNA ligases) that can cap either end of a polynucleotide substrate. GppDNA formed by RtcB3 can be decapped to pDNA by the DNA repair enzyme aprataxin. IMPORTANCE RtcB enzymes comprise a widely distributed family of RNA 3'-PO4 ligases distinguished by their formation of 3'-GMP-capped RNAppG and/or DNAppG polynucleotides. The mechanism and biochemical repertoire of E. coli RtcB are well studied, but it is unclear whether its properties apply to the many bacteria that have genes encoding multiple RtcB paralogs. A comparison of the biochemical activities of three M. xanthus paralogs, RtcB1, RtcB2, and RtcB3, shows that not all RtcBs are created equal. The standout findings concern RtcB3, which is (i) inactive as an RNA 3'-PO4 ligase but adept at capping a DNA 3'-PO4 end and (ii) able to cap DNA and RNA 5'-PO4 ends to form GppDNA and GppRNA, respectively. The GppDNA and GppRNA capping reactions are novel nucleic acid modifications.
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9
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Multiple conversion between the genes encoding bacterial class-I release factors. Sci Rep 2015; 5:12406. [PMID: 26257102 PMCID: PMC4530459 DOI: 10.1038/srep12406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/29/2015] [Indexed: 01/21/2023] Open
Abstract
Bacteria require two class-I release factors, RF1 and RF2, that recognize stop codons and promote peptide release from the ribosome. RF1 and RF2 were most likely established through gene duplication followed by altering their stop codon specificities in the common ancestor of extant bacteria. This scenario expects that the two RF gene families have taken independent evolutionary trajectories after the ancestral gene duplication event. However, we here report two independent cases of conversion between RF1 and RF2 genes (RF1-RF2 gene conversion), which were severely examined by procedures incorporating the maximum-likelihood phylogenetic method. In both cases, RF1-RF2 gene conversion was predicted to occur in the region encoding nearly entire domain 3, of which functions are common between RF paralogues. Nevertheless, the ‘direction’ of gene conversion appeared to be opposite from one another—from RF2 gene to RF1 gene in one case, while from RF1 gene to RF2 gene in the other. The two cases of RF1-RF2 gene conversion prompt us to propose two novel aspects in the evolution of bacterial class-I release factors: (i) domain 3 is interchangeable between RF paralogues, and (ii) RF1-RF2 gene conversion have occurred frequently in bacterial genome evolution.
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Janssen BD, Garza-Sánchez F, Hayes CS. YoeB toxin is activated during thermal stress. Microbiologyopen 2015; 4:682-97. [PMID: 26147890 PMCID: PMC4554461 DOI: 10.1002/mbo3.272] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 05/27/2015] [Indexed: 11/07/2022] Open
Abstract
Type II toxin-antitoxin (TA) modules are thought to mediate stress-responses by temporarily suppressing protein synthesis while cells redirect transcription to adapt to environmental change. Here, we show that YoeB, a ribosome-dependent mRNase toxin, is activated in Escherichia coli cells grown at elevated temperatures. YoeB activation is dependent on Lon protease, suggesting that thermal stress promotes increased degradation of the YefM antitoxin. Though YefM is efficiently degraded in response to Lon overproduction, we find that Lon antigen levels do not increase during heat shock, indicating that another mechanism accounts for temperature-induced YefM proteolysis. These observations suggest that YefM/YoeB functions in adaptation to temperature stress. However, this response is distinct from previously described models of TA function. First, YoeB mRNase activity is maintained over several hours of culture at 42°C, indicating that thermal activation is not transient. Moreover, heat-activated YoeB does not induce growth arrest nor does it suppress global protein synthesis. In fact, E. coli cells proliferate more rapidly at elevated temperatures and instantaneously accelerate their growth rate in response to acute heat shock. We propose that heat-activated YoeB may serve a quality control function, facilitating the recycling of stalled translation complexes through ribosome rescue pathways.
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Affiliation(s)
- Brian D Janssen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California
| | - Fernando Garza-Sánchez
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California.,Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California
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Basu A, Mishra B, Leong SSJ. Global transcriptome analysis reveals distinct bacterial response towards soluble and surface-immobilized antimicrobial peptide (Lasioglossin-III). RSC Adv 2015. [DOI: 10.1039/c5ra14862f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Bacterial response towards soluble and immobilized AMP molecules revealed through global transcriptome analysis.
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Affiliation(s)
- Anindya Basu
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
| | - Biswajit Mishra
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
| | - Susanna Su Jan Leong
- Singapore Institute of Technology
- Singapore 138683
- Department of Biochemistry
- Yong Loo Lin School of Medicine
- National University of Singapore
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Abstract
The most common prokaryotic signal transduction mechanisms are the one-component systems in which a single polypeptide contains both a sensory domain and a DNA-binding domain. Among the >20 classes of one-component systems, the TetR family of regulators (TFRs) are widely associated with antibiotic resistance and the regulation of genes encoding small-molecule exporters. However, TFRs play a much broader role, controlling genes involved in metabolism, antibiotic production, quorum sensing, and many other aspects of prokaryotic physiology. There are several well-established model systems for understanding these important proteins, and structural studies have begun to unveil the mechanisms by which they bind DNA and recognize small-molecule ligands. The sequences for more than 200,000 TFRs are available in the public databases, and genomics studies are identifying their target genes. Three-dimensional structures have been solved for close to 200 TFRs. Comparison of these structures reveals a common overall architecture of nine conserved α helices. The most important open question concerning TFR biology is the nature and diversity of their ligands and how these relate to the biochemical processes under their control.
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Antonov I, Coakley A, Atkins JF, Baranov PV, Borodovsky M. Identification of the nature of reading frame transitions observed in prokaryotic genomes. Nucleic Acids Res 2013; 41:6514-30. [PMID: 23649834 PMCID: PMC3711429 DOI: 10.1093/nar/gkt274] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our goal was to identify evolutionary conserved frame transitions in protein coding regions and to uncover an underlying functional role of these structural aberrations. We used the ab initio frameshift prediction program, GeneTack, to detect reading frame transitions in 206 991 genes (fs-genes) from 1106 complete prokaryotic genomes. We grouped 102 731 fs-genes into 19 430 clusters based on sequence similarity between protein products (fs-proteins) as well as conservation of predicted position of the frameshift and its direction. We identified 4010 pseudogene clusters and 146 clusters of fs-genes apparently using recoding (local deviation from using standard genetic code) due to possessing specific sequence motifs near frameshift positions. Particularly interesting was finding of a novel type of organization of the dnaX gene, where recoding is required for synthesis of the longer subunit, τ. We selected 20 clusters of predicted recoding candidates and designed a series of genetic constructs with a reporter gene or affinity tag whose expression would require a frameshift event. Expression of the constructs in Escherichia coli demonstrated enrichment of the set of candidates with sequences that trigger genuine programmed ribosomal frameshifting; we have experimentally confirmed four new families of programmed frameshifts.
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Affiliation(s)
- Ivan Antonov
- School of Computational Science and Engineering at Georgia Tech, Atlanta, GA 30332, USA
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Morita Y, Tomida J, Kawamura Y. MexXY multidrug efflux system of Pseudomonas aeruginosa. Front Microbiol 2012; 3:408. [PMID: 23233851 PMCID: PMC3516279 DOI: 10.3389/fmicb.2012.00408] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/13/2012] [Indexed: 01/01/2023] Open
Abstract
Anti-pseudomonas aminoglycosides, such as amikacin and tobramycin, are used in the treatment of Pseudomonas aeruginosa infections. However, their use is linked to the development of resistance. During the last decade, the MexXY multidrug efflux system has been comprehensively studied, and numerous reports of laboratory and clinical isolates have been published. This system has been increasingly recognized as one of the primary determinants of aminoglycoside resistance in P. aeruginosa. In P. aeruginosa cystic fibrosis isolates, upregulation of the pump is considered the most common mechanism of aminoglycoside resistance. Non-fermentative Gram-negative pathogens possessing very close MexXY orthologs such as Achromobacter xylosoxidans and various Burkholderia species (e.g., Burkholderia pseudomallei and B. cepacia complexes), but not B. gladioli, are intrinsically resistant to aminoglycosides. Here, we summarize the properties (e.g., discovery, mechanism, gene expression, clinical significance) of the P. aeruginosa MexXY pump and other aminoglycoside efflux pumps such as AcrD of Escherichia coli, AmrAB-OprA of B. pseudomallei, and AdeABC of Acinetobacter baumannii. MexXY inducibility of the PA5471 gene product, which is dependent on ribosome inhibition or oxidative stress, is noteworthy. Moreover, the discovery of the cognate outer membrane component (OprA) of MexXY in the multidrug-resistant clinical isolate PA7, serotype O12 deserves special attention.
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Affiliation(s)
- Yuji Morita
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
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Schaub RE, Poole SJ, Garza-Sánchez F, Benbow S, Hayes CS. Proteobacterial ArfA peptides are synthesized from non-stop messenger RNAs. J Biol Chem 2012; 287:29765-75. [PMID: 22791716 DOI: 10.1074/jbc.m112.374074] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The translation of non-stop mRNA (which lack in-frame stop codons) represents a significant quality control problem for all organisms. In eubacteria, the transfer-messenger RNA (tmRNA) system facilitates recycling of stalled ribosomes from non-stop mRNA in a process termed trans-translation or ribosome rescue. During rescue, the nascent chain is tagged with the tmRNA-encoded ssrA peptide, which promotes polypeptide degradation after release from the stalled ribosome. Escherichia coli possesses an additional ribosome rescue pathway mediated by the ArfA peptide. The E. coli arfA message contains a hairpin structure that is cleaved by RNase III to produce a non-stop transcript. Therefore, ArfA levels are controlled by tmRNA through ssrA-peptide tagging and proteolysis. Here, we examine whether ArfA homologues from other bacteria are also regulated by RNase III and tmRNA. We searched 431 arfA coding sequences for mRNA secondary structures and found that 82.8% of the transcripts contain predicted hairpins in their 3'-coding regions. The arfA hairpins from Haemophilus influenzae, Proteus mirabilis, Vibrio fischeri, and Pasteurella multocida are all cleaved by RNase III as predicted, whereas the hairpin from Neisseria gonorrhoeae functions as an intrinsic transcription terminator to generate non-stop mRNA. Each ArfA homologue is ssrA-tagged and degraded when expressed in wild-type E. coli cells, but accumulates in mutants lacking tmRNA. Together, these findings show that ArfA synthesis from non-stop mRNA is a conserved mechanism to regulate the alternative ribosome rescue pathway. This strategy ensures that ArfA homologues are only deployed when the tmRNA system is incapacitated or overwhelmed by stalled ribosomes.
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Affiliation(s)
- Ryan E Schaub
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106-9625, USA
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Duarte I, Nabuurs SB, Magno R, Huynen M. Evolution and diversification of the organellar release factor family. Mol Biol Evol 2012; 29:3497-512. [PMID: 22688947 PMCID: PMC3472500 DOI: 10.1093/molbev/mss157] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Translation termination is accomplished by proteins of the Class I release factor family (RF) that recognize stop codons and catalyze the ribosomal release of the newly synthesized peptide. Bacteria have two canonical RFs: RF1 recognizes UAA and UAG, RF2 recognizes UAA and UGA. Despite that these two release factor proteins are sufficient for de facto translation termination, the eukaryotic organellar RF protein family, which has evolved from bacterial release factors, has expanded considerably, comprising multiple subfamilies, most of which have not been functionally characterized or formally classified. Here, we integrate multiple sources of information to analyze the remarkable differentiation of the RF family among organelles. We document the origin, phylogenetic distribution and sequence structure features of the mitochondrial and plastidial release factors: mtRF1a, mtRF1, mtRF2a, mtRF2b, mtRF2c, ICT1, C12orf65, pRF1, and pRF2, and review published relevant experimental data. The canonical release factors (mtRF1a, mtRF2a, pRF1, and pRF2) and ICT1 are derived from bacterial ancestors, whereas the others have resulted from gene duplications of another release factor. These new RF family members have all lost one or more specific motifs relevant for bona fide release factor function but are mostly targeted to the same organelle as their ancestor. We also characterize the subset of canonical release factor proteins that bear nonclassical PxT/SPF tripeptide motifs and provide a molecular-model-based rationale for their retained ability to recognize stop codons. Finally, we analyze the coevolution of canonical RFs with the organellar genetic code. Although the RF presence in an organelle and its stop codon usage tend to coevolve, we find three taxa that encode an RF2 without using UGA stop codons, and one reverse scenario, where mamiellales green algae use UGA stop codons in their mitochondria without having a mitochondrial type RF2. For the latter, we put forward a “stop-codon reinvention” hypothesis that involves the retargeting of the plastid release factor to the mitochondrion.
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Affiliation(s)
- Isabel Duarte
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Janssen BD, Hayes CS. The tmRNA ribosome-rescue system. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 86:151-91. [PMID: 22243584 DOI: 10.1016/b978-0-12-386497-0.00005-0] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bacterial tmRNA quality control system monitors protein synthesis and recycles stalled translation complexes in a process termed "ribosome rescue." During rescue, tmRNA acts first as a transfer RNA to bind stalled ribosomes, then as a messenger RNA to add the ssrA peptide tag to the C-terminus of the nascent polypeptide chain. The ssrA peptide targets tagged peptides for proteolysis, ensuring rapid degradation of potentially deleterious truncated polypeptides. Ribosome rescue also facilitates turnover of the damaged messages responsible for translational arrest. Thus, tmRNA increases the fidelity of gene expression by promoting the synthesis of full-length proteins. In addition to serving as a global quality control system, tmRNA also plays important roles in bacterial development, pathogenesis, and environmental stress responses. This review focuses on the mechanism of tmRNA-mediated ribosome rescue and the role of tmRNA in bacterial physiology.
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Affiliation(s)
- Brian D Janssen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
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Abstract
Protein biosynthesis, or translation, occurs on the ribosome, a large RNA-protein assembly universally conserved in all forms of life. Over the last decade, structures of the small and large ribosomal subunits and of the intact ribosome have begun to reveal the molecular details of how the ribosome works. Both cryo-electron microscopy and X-ray crystallography continue to provide fresh insights into the mechanism of translation. In this review, we describe the most recent structural models of the bacterial ribosome that shed light on the movement of messenger RNA and transfer RNA on the ribosome after each peptide bond is formed, a process termed translocation. We also discuss recent structures that reveal the molecular basis for stop codon recognition during translation termination. Finally, we review recent advances in understanding how bacteria handle errors in both translocation and termination.
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Affiliation(s)
- Jack A Dunkle
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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Jiang L, Schaffitzel C, Bingel-Erlenmeyer R, Ban N, Korber P, Koning RI, de Geus DC, Plaisier JR, Abrahams JP. Recycling of Aborted Ribosomal 50S Subunit-Nascent Chain-tRNA Complexes by the Heat Shock Protein Hsp15. J Mol Biol 2009; 386:1357-67. [DOI: 10.1016/j.jmb.2008.10.079] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 09/19/2008] [Accepted: 10/26/2008] [Indexed: 10/21/2022]
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Bekaert M, Atkins JF, Baranov PV. ARFA: a program for annotating bacterial release factor genes, including prediction of programmed ribosomal frameshifting. ACTA ACUST UNITED AC 2006; 22:2463-5. [PMID: 16895933 DOI: 10.1093/bioinformatics/btl430] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
UNLABELLED Correct annotation of genes encoding release factors in bacterial genomes is often complicated by utilization of +1 programmed ribosomal frameshifting during synthesis of release factor 2, RF2. In the absence of robust computational approaches for predicting ribosomal frameshifting, the success of proper annotation depends on annotators' familiarity with this phenomenon. Here we describe a novel computer tool that allows automatic discrimination of genes encoding class-I bacterial release factors, RF1, RF2 and RFH. Most usefully, this program identifies and automatically annotates +1 frameshifting in RF2 encoding genes. Comparison of ARFA performance with existing annotations of bacterial genomes revealed that only 20% of RF2 genes utilizing ribosomal frameshifting during their expression are annotated correctly. AVAILABILITY The PHP based web interface of ARFA and the source code are located at http://recode.genetics.utah.edu/arfa
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Affiliation(s)
- Michaël Bekaert
- Biosciences Institute, University College Cork, Cork, Ireland
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