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Ngoennet S, Sirisattha S, Kusolkumbot P, Hibino T, Kageyama H, Waditee-Sirisattha R. Active role of the protein translation machinery in protecting against stress tolerance in Synechococcus elongatus PCC7942. Arch Biochem Biophys 2023; 746:109734. [PMID: 37648010 DOI: 10.1016/j.abb.2023.109734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 07/11/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023]
Abstract
In vivo protein synthesis is crucial for all domains of life. It is accomplished through translational machinery, and a key step is the translocation of tRNA-mRNA by elongation factor G (EF-G). Genome-based analysis revealed two EF-G encoding genes (S0885 and S2082) in the freshwater cyanobacterium model Synechococcus elongatus PCC7942. S0885 is the essential EF-G gene for photosynthesis. We generated a strain of S. elongatus PCC7942 that overexpressed S0885 (OX-S0885) to identify EF-G functionality. RT-PCR and Western blot analyses revealed increased transcriptional and translational levels in OX-S0885 at 10.5-13.5 and 2.0-3.0 fold, respectively. Overexpression of S0885 led to an increase in specific growth rate. Additionally, polysome-to-monosome ratio (P/M) and RNA-to-protein ratio (R/P) were elevated in OX-S0885 compared with the empty vector. Interestingly, R/P in OX-S0885 was retained at more than 70% under oxidative stress while R/P in the empty vector was severely depleted, suggesting the maintenance of translation. Thus, S0885 appeared to be the important target of oxidative stress because it was protected by the stress response system to maintain its function. These results suggest that cyanobacterial EF-G has a primary function in translation and an unrelated activity during stress conditions. These findings support the substantial role of EF-G in the formation and maintenance of cellular protein formation, and in the protection of the global translational mechanism under oxidative stress condition.
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Affiliation(s)
- Siripat Ngoennet
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand; Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Aichi, 468-8502, Japan
| | - Sophon Sirisattha
- Thailand Institute of Scientific and Technological Research (TISTR), Khlong Luang, Pathum Thani, 12120, Thailand
| | - Pokchut Kusolkumbot
- Thailand Institute of Scientific and Technological Research (TISTR), Khlong Luang, Pathum Thani, 12120, Thailand
| | - Takashi Hibino
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Aichi, 468-8502, Japan; Department of Chemistry, Faculty of Science and Technology, Meijo University, Nagoya, Aichi, 468-8502, Japan
| | - Hakuto Kageyama
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Aichi, 468-8502, Japan; Department of Chemistry, Faculty of Science and Technology, Meijo University, Nagoya, Aichi, 468-8502, Japan.
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2
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Kim JY, Jegal BS, Koh AR, Park KS, Kim JB, Bae J. Growth inhibition by fusidic acid in cervical, thyroid, and breast carcinoma cell lines. Obstet Gynecol Sci 2023; 66:100-106. [PMID: 36575560 PMCID: PMC10025870 DOI: 10.5468/ogs.22267] [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: 10/06/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE We investigated the effects of fusidic acid (FA) on human cervical, thyroid, and breast carcinoma cell lines to determine the potential usefulness of FA in cancer treatment. METHODS Six cancer cell lines (cervical cancer: Caski, HeLa; thyroid cancer: 8505C, TPC1; and breast cancer: MCF-7, MDA-MB-231) were treated with FA. Furthermore the changes in cell growth, cell cycle duration, and extent of apoptosis were analyzed. RESULTS After FA treatment, the cancer cells showed a decrease in growth rate. In the cell death assay, the cell populations were similar in each cell type after treatment with FA, indicating that growth inhibition by FA was not related to the induction of apoptosis. FA induced cell cycle arrest at a dose that inhibited growth rate, which varied in different cell types. G0/G1 phase arrest occurs in breast cancer, S phase arrest in 8505C thyroid cancer, and G2/M phase arrest in cervical cancer. These results indicate that FA reduces growth rates by inducing cell cycle arrest. CONCLUSION FA treatment can interfere with cell proliferation by inducing cell cycle arrest in human cervical, thyroid, and breast carcinoma cell lines. Thus, FA can be useful in treating human cervical, thyroid, and breast carcinomas.
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Affiliation(s)
- Jin Young Kim
- Department of Obstetrics and Gynecology, Hanyang University College of Medicine, Seoul,
Korea
| | - Bo Seul Jegal
- Department of Obstetrics and Gynecology, Hanyang University College of Medicine, Seoul,
Korea
| | - A Ra Koh
- Department of Obstetrics and Gynecology, Hanyang University College of Medicine, Seoul,
Korea
| | - Kyoung Sik Park
- Department Departments of Surgery, Konkuk University School of Medicine, Seoul,
Korea
| | | | - Jaeman Bae
- Department of Obstetrics and Gynecology, Hanyang University College of Medicine, Seoul,
Korea
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3
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Role of ribosome recycling factor in natural termination and translational coupling as a ribosome releasing factor. PLoS One 2023; 18:e0282091. [PMID: 36827443 PMCID: PMC9955659 DOI: 10.1371/journal.pone.0282091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/07/2023] [Indexed: 02/26/2023] Open
Abstract
The role of ribosome recycling factor (RRF) of E. coli was studied in vivo and in vitro. We used the translational coupling without the Shine-Dalgarno sequence of downstream ORF (d-ORF) as a model system of the RRF action in natural termination of protein synthesis. For the in vivo studies we used the translational coupling by the adjacent coat and lysis genes of RNA phage GA sharing the termination and initiation (UAAUG) and temperature sensitive RRF. The d-ORF translation was measured by the expression of the reporter lacZ gene connected to the 5'-terminal part of the lysis gene. The results showed that more ribosomes which finished upstream ORF (u-ORF) reading were used for downstream reading when RRF was inactivated. The in vitro translational coupling studies with 027mRNA having the junction sequence UAAUG with wild-type RRF were carried out with measuring amino acids incorporation. The results showed that ribosomes released by RRF read downstream from AUG of UAAUG. In the absence of RRF, ribosomes read downstream in frame with UAA. These in vivo and in vitro studies indicate that RRF releases ribosomes from mRNA at the termination codon of u-ORF. Furthermore, the non-dissociable ribosomes read downstream from AUG of UAAUG with RRF in vitro. This suggests that complete ribosomal splitting is not required for ribosome release by RRF in translational coupling. The data are consistent with the interpretation that RRF functions mostly as a ribosome releasing factor rather than ribosome splitting factor. Additionally, the in vivo studies showed that short (less than 5 codons) u-ORF inhibited d-ORF reading by ribosomes finishing u-ORF reading, suggesting that the termination process in short ORF is not similar to that in normal ORF. This means that all the preexisting studies on RRF with short mRNA may not represent what goes on in natural termination step.
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4
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Han W, Peng B, Wang C, Townsend GE, Barry NA, Peske F, Goodman AL, Liu J, Rodnina MV, Groisman EA. Gut colonization by Bacteroides requires translation by an EF-G paralog lacking GTPase activity. EMBO J 2023; 42:e112372. [PMID: 36472247 PMCID: PMC9841332 DOI: 10.15252/embj.2022112372] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
Protein synthesis is crucial for cell growth and survival yet one of the most energy-consuming cellular processes. How, then, do cells sustain protein synthesis under starvation conditions when energy is limited? To accelerate the translocation of mRNA-tRNAs through the ribosome, bacterial elongation factor G (EF-G) hydrolyzes energy-rich guanosine triphosphate (GTP) for every amino acid incorporated into a protein. Here, we identify an EF-G paralog-EF-G2-that supports translocation without hydrolyzing GTP in the gut commensal bacterium Bacteroides thetaiotaomicron. EF-G2's singular ability to sustain protein synthesis, albeit at slow rates, is crucial for bacterial gut colonization. EF-G2 is ~10-fold more abundant than canonical EF-G1 in bacteria harvested from murine ceca and, unlike EF-G1, specifically accumulates during carbon starvation. Moreover, we uncover a 26-residue region unique to EF-G2 that is essential for protein synthesis, EF-G2 dissociation from the ribosome, and responsible for the absence of GTPase activity. Our findings reveal how cells curb energy consumption while maintaining protein synthesis to advance fitness in nutrient-fluctuating environments.
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Affiliation(s)
- Weiwei Han
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Bee‐Zen Peng
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Chunyan Wang
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Guy E Townsend
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
- Present address:
Department of Biochemistry and Molecular BiologyPenn State College of MedicineHersheyPAUSA
| | - Natasha A Barry
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Frank Peske
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Andrew L Goodman
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Jun Liu
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Marina V Rodnina
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Eduardo A Groisman
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
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5
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Gene-Gene Interactions Reduce Aminoglycoside Susceptibility of Pseudomonas aeruginosa through Efflux Pump-Dependent and -Independent Mechanisms. Antibiotics (Basel) 2023; 12:antibiotics12010152. [PMID: 36671353 PMCID: PMC9854422 DOI: 10.3390/antibiotics12010152] [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: 12/21/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Pseudomonas aeruginosa causes a wide range of acute and chronic infections. Aminoglycosides are a cornerstone of treatment, but isolates are often resistant. The purpose of this research was to better understand the genetic basis of aminoglycoside resistance in P. aeruginosa. Bioinformatic approaches identified mutations in resistance-associated genes in the clinical isolates of P. aeruginosa. The common mutations were then engineered into the genome of P. aeruginosa reference strain PAO1. Mutations in the elongation factor gene fusA1 caused the biggest reduction in aminoglycoside susceptibility, with mutations in the two-component regulator gene amgS and the efflux pump regulator gene mexZ having less impact. This susceptibility was further reduced by combinations of mutations. Mutations in fusA1, amgS and mexZ all increased the expression of the mexXY efflux pump that is strongly associated with aminoglycoside resistance. Furthermore, the fusA1 amgS mexZ triple mutant had the highest efflux pump gene expression. Engineering fusA1 and amgS mutants lacking this efflux pump showed that fusA1 and amgS also reduce aminoglycoside susceptibility through additional mechanisms. The fusA1 and amgS mutations reduced bacterial growth, showing that these mutations have a fitness cost. Our findings demonstrate the complex interplay between mutations, efflux pump expression and other mechanisms for reducing the susceptibility of P. aeruginosa to aminoglycosides.
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6
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Abstract
Translocation of transfer RNA (tRNA) and messenger RNA (mRNA) through the ribosome is catalyzed by the GTPase elongation factor G (EF-G) in bacteria. Although guanosine-5'-triphosphate (GTP) hydrolysis accelerates translocation and is required for dissociation of EF-G, its fundamental role remains unclear. Here, we used ensemble Förster resonance energy transfer (FRET) to monitor how inhibition of GTP hydrolysis impacts the structural dynamics of the ribosome. We used FRET pairs S12-S19 and S11-S13, which unambiguously report on rotation of the 30S head domain, and the S6-L9 pair, which measures intersubunit rotation. Our results show that, in addition to slowing reverse intersubunit rotation, as shown previously, blocking GTP hydrolysis slows forward head rotation. Surprisingly, blocking GTP hydrolysis completely abolishes reverse head rotation. We find that the S13-L33 FRET pair, which has been used in previous studies to monitor head rotation, appears to report almost exclusively on intersubunit rotation. Furthermore, we find that the signal from quenching of 3'-terminal pyrene-labeled mRNA, which is used extensively to follow mRNA translocation, correlates most closely with reverse intersubunit rotation. To account for our finding that blocking GTP hydrolysis abolishes a rotational event that occurs after the movements of mRNA and tRNAs are essentially complete, we propose that the primary role of GTP hydrolysis is to create an irreversible step in a mechanism that prevents release of EF-G until both the tRNAs and mRNA have moved by one full codon, ensuring productive translocation and maintenance of the translational reading frame.
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7
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Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen that usually causes difficult-to-treat infections due to its low intrinsic antibiotic susceptibility and outstanding capacity for becoming resistant to antibiotics. In addition, it has a remarkable metabolic versatility, being able to grow in different habitats, from natural niches to different and changing inpatient environments. Study of the environmental conditions that shape genetic and phenotypic changes of P. aeruginosa toward antibiotic resistance supposes a novelty, since experimental evolution assays are usually performed with well-defined antibiotics in regular laboratory growth media. Therefore, in this work we address the extent to which the nutrients’ availability may constrain the evolution of antibiotic resistance. We determined that P. aeruginosa genetic trajectories toward resistance to tobramycin, ceftazidime, and ceftazidime-avibactam are different when evolving in laboratory rich medium, urine, or synthetic sputum. Furthermore, our study, linking genotype with phenotype, showed a clear impact of each analyzed environment on both the fitness and resistance level associated with particular resistance mutations. This indicates that the phenotype associated with specific resistance mutations is variable and dependent on the bacterial metabolic state in each particular habitat. Our results support that the design of evolution-based strategies to tackle P. aeruginosa infections should be based on robust patterns of evolution identified within each particular infection and body location. IMPORTANCE Predicting evolution toward antibiotic resistance (AR) and its associated trade-offs, such as collateral sensitivity, is important to design evolution-based strategies to tackle AR. However, the effect of nutrients' availability on such evolution, particularly those that can be found under in vivo infection conditions, has been barely addressed. We analyzed the evolutionary patterns of P. aeruginosa in the presence of antibiotics in different media, including urine and synthetic sputum, whose compositions are similar to the ones in infections, finding that AR evolution differs, depending on growth conditions. Furthermore, the representative mutants isolated under each condition tested render different AR levels and fitness costs, depending on nutrients’ availability, supporting the idea that environmental constraints shape the phenotypes associated with specific AR mutations. Consequently, the selection of AR mutations that render similar phenotypes is environment dependent. The analysis of evolution patterns toward AR requires studying growth conditions mimicking those that bacteria face during in vivo evolution.
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8
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García-Descalzo L, García-López E, Cid C. Comparative Proteomic Analysis of Psychrophilic vs. Mesophilic Bacterial Species Reveals Different Strategies to Achieve Temperature Adaptation. Front Microbiol 2022; 13:841359. [PMID: 35591995 PMCID: PMC9111180 DOI: 10.3389/fmicb.2022.841359] [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] [Received: 12/22/2021] [Accepted: 03/08/2022] [Indexed: 11/16/2022] Open
Abstract
The old debate of nature (genes) vs. nurture (environmental variables) is once again topical concerning the effect of climate change on environmental microorganisms. Specifically, the Polar Regions are experiencing a drastic increase in temperature caused by the rise in greenhouse gas emissions. This study, in an attempt to mimic the molecular adaptation of polar microorganisms, combines proteomic approaches with a classical microbiological analysis in three bacterial species Shewanella oneidensis, Shewanella frigidimarina, and Psychrobacter frigidicola. Both shewanellas are members of the same genus but they live in different environments. On the other hand, Shewanella frigidimarina and Psychrobacter frigidicola share the same natural environment but belong to a different genus. The comparison of the strategies employed by each bacterial species estimates the contribution of genome vs. environmental variables in the adaptation to temperature. The results show a greater versatility of acclimatization for the genus Shewanella with respect to Psychrobacter. Besides, S. frigidimarina was the best-adapted species to thermal variations in the temperature range 4–30°C and displayed several adaptation mechanisms common with the other two species. Regarding the molecular machinery used by these bacteria to face the consequences of temperature changes, chaperones have a pivoting role. They form complexes with other proteins in the response to the environment, establishing cooperation with transmembrane proteins, elongation factors, and proteins for protection against oxidative damage.
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Affiliation(s)
- Laura García-Descalzo
- Centro de Astrobiología, Department of Planetology and Habitability, CSIC-INTA, Madrid, Spain
| | - Eva García-López
- Centro de Astrobiología, Department of Molecular Ecology, CSIC-INTA, Madrid, Spain
| | - Cristina Cid
- Centro de Astrobiología, Department of Molecular Ecology, CSIC-INTA, Madrid, Spain
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9
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Iron–sulfur clusters as inhibitors and catalysts of viral replication. Nat Chem 2022; 14:253-266. [DOI: 10.1038/s41557-021-00882-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
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10
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Xu B, Liu L, Song G. Functions and Regulation of Translation Elongation Factors. Front Mol Biosci 2022; 8:816398. [PMID: 35127825 PMCID: PMC8807479 DOI: 10.3389/fmolb.2021.816398] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/20/2021] [Indexed: 12/18/2022] Open
Abstract
Translation elongation is a key step of protein synthesis, during which the nascent polypeptide chain extends by one amino acid residue during one elongation cycle. More and more data revealed that the elongation is a key regulatory node for translational control in health and disease. During elongation, elongation factor Tu (EF-Tu, eEF1A in eukaryotes) is used to deliver aminoacyl-tRNA (aa-tRNA) to the A-site of the ribosome, and elongation factor G (EF-G, EF2 in eukaryotes and archaea) is used to facilitate the translocation of the tRNA2-mRNA complex on the ribosome. Other elongation factors, such as EF-Ts/eEF1B, EF-P/eIF5A, EF4, eEF3, SelB/EFsec, TetO/Tet(M), RelA and BipA, have been found to affect the overall rate of elongation. Here, we made a systematic review on the canonical and non-canonical functions and regulation of these elongation factors. In particular, we discussed the close link between translational factors and human diseases, and clarified how post-translational modifications control the activity of translational factors in tumors.
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Affiliation(s)
- Benjin Xu
- Department of Medical Laboratory Science, Fenyang College, Shanxi Medical University, Fenyang, China
- *Correspondence: Benjin Xu, ; Guangtao Song,
| | - Ling Liu
- Department of Medical Laboratory Science, Fenyang College, Shanxi Medical University, Fenyang, China
| | - Guangtao Song
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- *Correspondence: Benjin Xu, ; Guangtao Song,
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11
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Long J, Ji W, Zhang D, Zhu Y, Bi Y. Bioactivities and Structure-Activity Relationships of Fusidic Acid Derivatives: A Review. Front Pharmacol 2021; 12:759220. [PMID: 34721042 PMCID: PMC8554340 DOI: 10.3389/fphar.2021.759220] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 09/27/2021] [Indexed: 12/22/2022] Open
Abstract
Fusidic acid (FA) is a natural tetracyclic triterpene isolated from fungi, which is clinically used for systemic and local staphylococcal infections, including methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci infections. FA and its derivatives have been shown to possess a wide range of pharmacological activities, including antibacterial, antimalarial, antituberculosis, anticancer, tumor multidrug resistance reversal, anti-inflammation, antifungal, and antiviral activity in vivo and in vitro. The semisynthesis, structural modification and biological activities of FA derivatives have been extensively studied in recent years. This review summarized the biological activities and structure-activity relationship (SAR) of FA in the last two decades. This summary can prove useful information for drug exploration of FA derivatives.
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Affiliation(s)
- Junjun Long
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
| | - Wentao Ji
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
| | - Doudou Zhang
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
| | - Yifei Zhu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
| | - Yi Bi
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
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12
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Koripella RK, Deep A, Agrawal EK, Keshavan P, Banavali NK, Agrawal RK. Distinct mechanisms of the human mitoribosome recycling and antibiotic resistance. Nat Commun 2021; 12:3607. [PMID: 34127662 PMCID: PMC8203779 DOI: 10.1038/s41467-021-23726-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/14/2021] [Indexed: 11/16/2022] Open
Abstract
Ribosomes are recycled for a new round of translation initiation by dissociation of ribosomal subunits, messenger RNA and transfer RNA from their translational post-termination complex. Here we present cryo-EM structures of the human 55S mitochondrial ribosome (mitoribosome) and the mitoribosomal large 39S subunit in complex with mitoribosome recycling factor (RRFmt) and a recycling-specific homolog of elongation factor G (EF-G2mt). These structures clarify an unusual role of a mitochondria-specific segment of RRFmt, identify the structural distinctions that confer functional specificity to EF-G2mt, and show that the deacylated tRNA remains with the dissociated 39S subunit, suggesting a distinct sequence of events in mitoribosome recycling. Furthermore, biochemical and structural analyses reveal that the molecular mechanism of antibiotic fusidic acid resistance for EF-G2mt is markedly different from that of mitochondrial elongation factor EF-G1mt, suggesting that the two human EF-Gmts have evolved diversely to negate the effect of a bacterial antibiotic. High-resolution cryo-EM structures and biochemical analyses of the human mitoribosome, in complex with mitochondria-specific factors mediating mitoribosome recycling, RRFmt and EF-G2mt, offer insight into mechanisms of mitoribosome recycling and resistance to antibiotic fusidic acid.
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Affiliation(s)
- Ravi Kiran Koripella
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Ayush Deep
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Ekansh K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Pooja Keshavan
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Nilesh K Banavali
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA.,Department of Biomedical Sciences, University at Albany, Albany, NY, USA
| | - Rajendra K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA. .,Department of Biomedical Sciences, University at Albany, Albany, NY, USA.
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13
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Akanuma G. Diverse relationships between metal ions and the ribosome. Biosci Biotechnol Biochem 2021; 85:1582-1593. [PMID: 33877305 DOI: 10.1093/bbb/zbab070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/30/2021] [Indexed: 11/12/2022]
Abstract
The ribosome requires metal ions for structural stability and translational activity. These metal ions are important for stabilizing the secondary structure of ribosomal RNA, binding of ribosomal proteins to the ribosome, and for interaction of ribosomal subunits. In this review, various relationships between ribosomes and metal ions, especially Mg2+ and Zn2+, are presented. Mg2+ regulates gene expression by modulating the translational stability and synthesis of ribosomes, which in turn contribute to the cellular homeostasis of Mg2+. In addition, Mg2+ can partly complement the function of ribosomal proteins. Conversely, a reduction in the cellular concentration of Zn2+ induces replacement of ribosomal proteins, which mobilizes free-Zn2+ in the cell and represses translation activity. Evolutional relationships between these metal ions and the ribosome are also discussed.
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Affiliation(s)
- Genki Akanuma
- Department of Life Science, Graduate School of Science, Gakushuin University, Toshima-ku, Tokyo, Japan.,Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
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14
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Zhang L, He J, Bai L, Ruan S, Yang T, Luo Y. Ribosome-targeting antibacterial agents: Advances, challenges, and opportunities. Med Res Rev 2021; 41:1855-1889. [PMID: 33501747 DOI: 10.1002/med.21780] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/08/2020] [Accepted: 12/19/2020] [Indexed: 02/05/2023]
Abstract
Ribosomes, which synthesize proteins, are critical organelles for the survival and growth of bacteria. About 60% of approved antibiotics discovered so far combat pathogenic bacteria by targeting ribosomes. However, several issues, such as drug resistance and toxicity, have impeded the clinical use of ribosome-targeting antibiotics. Moreover, the complexity of the bacteria ribosome structure has retarded the discovery of new ribosome-targeting agents that are considered as the key to the drug-resistance and toxicity. To deal with these challenges, efforts such as medicinal chemistry optimization, combination treatment, and new drug delivery system have been developed. But not enough, the development of structural biology and new screening methods bring powerful tools, such as cryo-electron microscopy technology, advanced computer-aided drug design, and cell-free in vitro transcription/translation systems, for the discovery of novel ribosome-targeting antibiotics. Thus, in this paper, we overview the research on different aspects of bacterial ribosomes, especially focus on discussing the challenges in the discovery of ribosome-targeting antibacterial drugs and advances made to address issues such as drug-resistance and selectivity, which, we believe, provide perspectives for the discovery of novel antibiotics.
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Affiliation(s)
- Laiying Zhang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China
| | - Jun He
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China
| | - Lang Bai
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China
| | - Shihua Ruan
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China
| | - Tao Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China.,Laboratory of Human Diseases and Immunotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China.,Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China
| | - Youfu Luo
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, China
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15
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Lee M, Matsunaga N, Akabane S, Yasuda I, Ueda T, Takeuchi-Tomita N. Reconstitution of mammalian mitochondrial translation system capable of correct initiation and long polypeptide synthesis from leaderless mRNA. Nucleic Acids Res 2021; 49:371-382. [PMID: 33300043 PMCID: PMC7797035 DOI: 10.1093/nar/gkaa1165] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/31/2022] Open
Abstract
Mammalian mitochondria have their own dedicated protein synthesis system, which produces 13 essential subunits of the oxidative phosphorylation complexes. We have reconstituted an in vitro translation system from mammalian mitochondria, utilizing purified recombinant mitochondrial translation factors, 55S ribosomes from pig liver mitochondria, and a tRNA mixture from either Escherichia coli or yeast. The system is capable of translating leaderless mRNAs encoding model proteins (DHFR and nanoLuciferase) or some mtDNA-encoded proteins. We show that a leaderless mRNA, encoding nanoLuciferase, is faithfully initiated without the need for any auxiliary factors other than IF-2mt and IF-3mt. We found that the ribosome-dependent GTPase activities of both the translocase EF-G1mt and the recycling factor EF-G2mt are insensitive to fusidic acid (FA), the translation inhibitor that targets bacterial EF-G homologs, and consequently the system is resistant to FA. Moreover, we demonstrate that a polyproline sequence in the protein causes 55S mitochondrial ribosome stalling, yielding ribosome nascent chain complexes. Analyses of the effects of the Mg concentration on the polyproline-mediated ribosome stalling suggested the unique regulation of peptide elongation by the mitoribosome. This system will be useful for analyzing the mechanism of translation initiation, and the interactions between the nascent peptide chain and the mitochondrial ribosome.
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Affiliation(s)
- Muhoon Lee
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Noriko Matsunaga
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Shiori Akabane
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan.,Department of Life Science, Rikkyo University, Tokyo, 171-8501, Japan
| | - Ippei Yasuda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan.,Department of Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, Tokyo, Shinjuku 162-8480, Japan
| | - Nono Takeuchi-Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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16
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Maunders EA, Triniman RC, Western J, Rahman T, Welch M. Global reprogramming of virulence and antibiotic resistance in Pseudomonas aeruginosa by a single nucleotide polymorphism in elongation factor, fusA1. J Biol Chem 2020; 295:16411-16426. [PMID: 32943550 DOI: 10.1074/jbc.ra119.012102] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 09/11/2020] [Indexed: 11/06/2022] Open
Abstract
Clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa from patients with cystic fibrosis (CF) frequently contain mutations in the gene encoding an elongation factor, FusA1. Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the efflux pump, MexXY. However, we wondered whether these mutants might also be affected in other virulence-associated phenotypes. Here, we isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1P443L) in which mexXY expression was increased. Proteomic and transcriptomic analyses revealed that the fusA1 mutant also exhibited discrete changes in the expression of key pathogenicity-associated genes. Most notably, the fusA1 mutant displayed greatly increased expression of the Type III secretion system (T3SS), widely considered to be the most potent virulence factor in the P. aeruginosa arsenal, and also elevated expression of the Type VI (T6) secretion machinery. This was unexpected because expression of the T3SS is usually reciprocally coordinated with T6 secretion system expression. The fusA1 mutant also displayed elevated exopolysaccharide production, dysregulated siderophore production, elevated ribosome synthesis, and transcriptomic signatures indicative of translational stress. Each of these phenotypes (and almost all of the transcriptomic and proteomic changes associated with the fusA1 mutation) were restored to levels comparable with that in the progenitor strain by expression of the WT fusA1 gene in trans, indicating that the mutant gene is recessive. Our data show that in addition to elevating antibiotic resistance through mexXY expression (and also additional contributory resistance mechanisms), mutations in fusA1 can lead to highly selective dysregulation of virulence gene expression.
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Affiliation(s)
- Eve A Maunders
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Rory C Triniman
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom; Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Joshua Western
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
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17
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Rodnina MV, Peske F, Peng BZ, Belardinelli R, Wintermeyer W. Converting GTP hydrolysis into motion: versatile translational elongation factor G. Biol Chem 2020; 401:131-142. [PMID: 31600135 DOI: 10.1515/hsz-2019-0313] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/24/2019] [Indexed: 12/16/2022]
Abstract
Elongation factor G (EF-G) is a translational GTPase that acts at several stages of protein synthesis. Its canonical function is to catalyze tRNA movement during translation elongation, but it also acts at the last step of translation to promote ribosome recycling. Moreover, EF-G has additional functions, such as helping the ribosome to maintain the mRNA reading frame or to slide over non-coding stretches of the mRNA. EF-G has an unconventional GTPase cycle that couples the energy of GTP hydrolysis to movement. EF-G facilitates movement in the GDP-Pi form. To convert the energy of hydrolysis to movement, it requires various ligands in the A site, such as a tRNA in translocation, an mRNA secondary structure element in ribosome sliding, or ribosome recycling factor in post-termination complex disassembly. The ligand defines the direction and timing of EF-G-facilitated motion. In this review, we summarize recent advances in understanding the mechanism of EF-G action as a remarkable force-generating GTPase.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Bee-Zen Peng
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Riccardo Belardinelli
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Wolfgang Wintermeyer
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
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18
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Kavčič B, Tkačik G, Bollenbach T. Mechanisms of drug interactions between translation-inhibiting antibiotics. Nat Commun 2020; 11:4013. [PMID: 32782250 PMCID: PMC7421507 DOI: 10.1038/s41467-020-17734-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 07/14/2020] [Indexed: 02/03/2023] Open
Abstract
Antibiotics that interfere with translation, when combined, interact in diverse and difficult-to-predict ways. Here, we explain these interactions by "translation bottlenecks": points in the translation cycle where antibiotics block ribosomal progression. To elucidate the underlying mechanisms of drug interactions between translation inhibitors, we generate translation bottlenecks genetically using inducible control of translation factors that regulate well-defined translation cycle steps. These perturbations accurately mimic antibiotic action and drug interactions, supporting that the interplay of different translation bottlenecks causes these interactions. We further show that growth laws, combined with drug uptake and binding kinetics, enable the direct prediction of a large fraction of observed interactions, yet fail to predict suppression. However, varying two translation bottlenecks simultaneously supports that dense traffic of ribosomes and competition for translation factors account for the previously unexplained suppression. These results highlight the importance of "continuous epistasis" in bacterial physiology.
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Affiliation(s)
- Bor Kavčič
- Institute of Science and Technology Austria, Am Campus 1, A-3400, Klosterneuburg, Austria
| | - Gašper Tkačik
- Institute of Science and Technology Austria, Am Campus 1, A-3400, Klosterneuburg, Austria
| | - Tobias Bollenbach
- Institute for Biological Physics, University of Cologne, Zülpicher Str. 77, D-50937, Cologne, Germany.
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19
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Pradal I, Esteban J, Mediero A, García-Coca M, Aguilera-Correa JJ. Contact Effect of a Methylobacterium sp. Extract on Biofilm of a Mycobacterium chimaera Strain Isolated from a 3T Heater-Cooler System. Antibiotics (Basel) 2020; 9:E474. [PMID: 32756304 PMCID: PMC7460266 DOI: 10.3390/antibiotics9080474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/22/2020] [Accepted: 07/29/2020] [Indexed: 11/17/2022] Open
Abstract
Mycobacterium chimaera is an opportunistic slowly growing non-tuberculous mycobacteriumof increasing importance due to the outbreak of cases associated with contaminated 3T heater-cooler device (HCD) extracorporeal membrane oxygenator (ECMO). The aim of this study was to evaluate the effect of pre-treating a surface with a Methylobacterium sp. CECT 7180 extract to inhibit the M. chimaera ECMO biofilm as well as of the treatment after different dehydration times. Surface adherence, biofilm formation and treatment effect were evaluated by estimating colony-forming units (CFU) per square centimeter and characterizing the amount of covered surface area, thickness, cell viability, and presence of intrinsic autofluorescence at different times using confocal laser scanning microscopy and image analysis. We found that exposing a surface to the Methylobacterium sp. CECT 7180 extract inhibited M. chimaera ECMO biofilm development. This effect could be result of the effect of Methylobacterium proteins, such as DNaK, trigger factor, and xanthine oxidase. In conclusion, exposing a surface to the Methylobacteriumsp. extract inhibits M. chimaera ECMO biofilm development. Furthermore, this extract could be used as a pre-treatment prior to disinfection protocols for equipment contaminated with mycobacteria after dehydration for at least 96 h.
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Affiliation(s)
- Inés Pradal
- Clinical Microbiology Department, IIS-Fundación Jiménez Díaz, UAM, 28040 Madrid, Spain
| | - Jaime Esteban
- Clinical Microbiology Department, IIS-Fundación Jiménez Díaz, UAM, 28040 Madrid, Spain
| | - Arancha Mediero
- Bone and Joint Unit, IIS-Fundación Jiménez Díaz, UAM, 28040 Madrid, Spain
| | - Marta García-Coca
- Clinical Microbiology Department, Quironsalud-Madrid University Hospital, 28223 Pozuelo de Alarcón, Spain
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20
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Abstract
The rise of antimicrobial resistance is a leading medical threat, motivating efforts to forecast both its evolutionary dynamics and its genetic causes. Aminoglycosides are a major class of antibiotics that disrupt translation, but resistance may occur by a number of mechanisms. Here, we show the repeated evolution of resistance to the aminoglycoside tobramycin in both P. aeruginosa and A. baumannii via mutations in fusA1, encoding elongation factor G, and ptsP, encoding the nitrogen-specific phosphotransferase system. Laboratory evolution and whole-population genome sequencing were used to identify these targets, but mutations at identical amino acid positions were also found in published genomes of diverse bacterial species and clinical isolates. We also identified other resistance mechanisms associated with growth in biofilms that likely interfere with drug binding or uptake. Characterizing the evolution of multiple species in the presence of antibiotics can identify new, repeatable causes of resistance that may be predicted and counteracted by alternative treatment. Different species exposed to a common stress may adapt by mutations in shared pathways or in unique systems, depending on how past environments have molded their genomes. Understanding how diverse bacterial pathogens evolve in response to an antimicrobial treatment is a pressing example of this problem, where discovery of molecular parallelism could lead to clinically useful predictions. Evolution experiments with pathogens in environments containing antibiotics, combined with periodic whole-population genome sequencing, can be used to identify many contending routes to antimicrobial resistance. We separately propagated two clinically relevant Gram-negative pathogens, Pseudomonas aeruginosa and Acinetobacter baumannii, in increasing concentrations of tobramycin in two different environments each: planktonic and biofilm. Independently of the pathogen, the populations adapted to tobramycin selection by parallel evolution of mutations in fusA1, encoding elongation factor G, and ptsP, encoding phosphoenolpyruvate phosphotransferase. As neither gene is a direct target of this aminoglycoside, mutations to either are unexpected and underreported causes of resistance. Additionally, both species acquired antibiotic resistance-associated mutations that were more prevalent in the biofilm lifestyle than in the planktonic lifestyle; these mutations were in electron transport chain components in A. baumannii and lipopolysaccharide biosynthesis enzymes in P. aeruginosa populations. Using existing databases, we discovered site-specific parallelism of fusA1 mutations that extends across bacterial phyla and clinical isolates. This study suggests that strong selective pressures, such as antibiotic treatment, may result in high levels of predictability in molecular targets of evolution, despite differences between organisms’ genetic backgrounds and environments.
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21
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Structural basis for ribosome recycling by RRF and tRNA. Nat Struct Mol Biol 2019; 27:25-32. [PMID: 31873307 DOI: 10.1038/s41594-019-0350-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/12/2019] [Indexed: 11/08/2022]
Abstract
The bacterial ribosome is recycled into subunits by two conserved proteins, elongation factor G (EF-G) and the ribosome recycling factor (RRF). The molecular basis for ribosome recycling by RRF and EF-G remains unclear. Here, we report the crystal structure of a posttermination Thermus thermophilus 70S ribosome complexed with EF-G, RRF and two transfer RNAs at a resolution of 3.5 Å. The deacylated tRNA in the peptidyl (P) site moves into a previously unsuspected state of binding (peptidyl/recycling, p/R) that is analogous to that seen during initiation. The terminal end of the p/R-tRNA forms nonfavorable contacts with the 50S subunit while RRF wedges next to central inter-subunit bridges, illuminating the active roles of tRNA and RRF in dissociation of ribosomal subunits. The structure uncovers a missing snapshot of tRNA as it transits between the P and exit (E) sites, providing insights into the mechanisms of ribosome recycling and tRNA translocation.
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22
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Pilla SP, Thomas A, Bahadur RP. Dissecting macromolecular recognition sites in ribosome: implication to its self-assembly. RNA Biol 2019; 16:1300-1312. [PMID: 31179876 DOI: 10.1080/15476286.2019.1629767] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Interactions between macromolecules play a crucial role in ribosome assembly that follows a highly coordinated process involving RNA folding and binding of ribosomal proteins (r-proteins). Although extensive studies have been carried out to understand macromolecular interactions in ribosomes, most of them are confined to either large or small ribosomal-subunit of few species. A comparative analysis of macromolecular interactions across different domains is still missing. We have analyzed the structural and physicochemical properties of protein-protein (PP), protein-RNA (PR) and RNA-RNA (RR) interfaces in small and large subunits of ribosomes, as well as in between the two subunits. Additionally, we have also developed Random Forest (RF) classifier to catalog the r-proteins. We find significant differences as well as similarities in macromolecular recognition sites between ribosomal assemblies of prokaryotes and eukaryotes. PR interfaces are substantially larger and have more ionic interactions than PP and RR interfaces in both prokaryotes and eukaryotes. PP, PR and RR interfaces in eukaryotes are well packed compared to those in prokaryotes. However, the packing density between the large and the small subunit interfaces in the entire assembly is strikingly low in both prokaryotes and eukaryotes, indicating the periodic association and dissociation of the two subunits during the translation. The structural and physicochemical properties of PR interfaces are used to predict the r-proteins in the assembly pathway into early, intermediate and late binders using RF classifier with an accuracy of 80%. The results provide new insights into the classification of r-proteins in the assembly pathway.
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Affiliation(s)
- Smita P Pilla
- a Computational Structural Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur , Kharagpur , India
| | - Amal Thomas
- a Computational Structural Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur , Kharagpur , India
| | - Ranjit Prasad Bahadur
- a Computational Structural Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur , Kharagpur , India
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23
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Girodat D, Mercier E, Gzyl KE, Wieden HJ. Elongation Factor Tu's Nucleotide Binding Is Governed by a Thermodynamic Landscape Unique among Bacterial Translation Factors. J Am Chem Soc 2019; 141:10236-10246. [PMID: 31058500 DOI: 10.1021/jacs.9b01522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Molecular switches such as GTPases are powerful devices turning "on" or "off" biomolecular processes at the core of critical biological pathways. To develop molecular switches de novo, an intimate understanding of how they function is required. Here we investigate the thermodynamic parameters that define the nucleotide-dependent switch mechanism of elongation factor (EF) Tu as a prototypical molecular switch. EF-Tu alternates between GTP- and GDP-bound conformations during its functional cycle, representing the "on" and "off" states, respectively. We report for the first time that the activation barriers for nucleotide association are the same for both nucleotides, suggesting a guanosine nucleoside or ribose-first mechanism for nucleotide association. Additionally, molecular dynamics (MD) simulations indicate that enthalpic stabilization of GDP binding compared to GTP binding originates in the backbone hydrogen bonding network of EF-Tu. In contrast, binding of GTP to EF-Tu is entropically driven by the liberation of bound water during the GDP- to GTP-bound transition. GDP binding to the apo conformation of EF-Tu is both enthalpically and entropically favored, a feature unique among translational GTPases. This indicates that the apo conformation does not resemble the GDP-bound state. Finally, we show that antibiotics and single amino acid substitutions can be used to target specific structural elements in EF-Tu to redesign the thermodynamic landscape. These findings demonstrate how, through evolution, EF-Tu has fine-tuned the structural and dynamic features that define nucleotide binding, providing insight into how altering these properties could be exploited for protein engineering.
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Affiliation(s)
- Dylan Girodat
- Alberta RNA Research and Training Institute (ARRTI), Department of Chemistry and Biochemistry , University of Lethbridge , 4401 University Drive West , Lethbridge , Alberta T1K 3M4 , Canada
| | - Evan Mercier
- Alberta RNA Research and Training Institute (ARRTI), Department of Chemistry and Biochemistry , University of Lethbridge , 4401 University Drive West , Lethbridge , Alberta T1K 3M4 , Canada
| | - Katherine E Gzyl
- Alberta RNA Research and Training Institute (ARRTI), Department of Chemistry and Biochemistry , University of Lethbridge , 4401 University Drive West , Lethbridge , Alberta T1K 3M4 , Canada
| | - Hans-Joachim Wieden
- Alberta RNA Research and Training Institute (ARRTI), Department of Chemistry and Biochemistry , University of Lethbridge , 4401 University Drive West , Lethbridge , Alberta T1K 3M4 , Canada
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24
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Structural insights into unique features of the human mitochondrial ribosome recycling. Proc Natl Acad Sci U S A 2019; 116:8283-8288. [PMID: 30962385 PMCID: PMC6486771 DOI: 10.1073/pnas.1815675116] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Mammalian mitochondrial ribosomes (mitoribosomes) are responsible for synthesizing proteins that are essential for oxidative phosphorylation (ATP generation). Despite their common ancestry with bacteria, the composition and structure of the human mitoribosome and its translational factors are significantly different from those of their bacterial counterparts. The mammalian mitoribosome recycling factor (RRFmt) carries a mito-specific N terminus extension (NTE), which is necessary for the function of RRFmt Here we present a 3.9-Å resolution cryo-electron microscopic (cryo-EM) structure of the human 55S mitoribosome-RRFmt complex, which reveals α-helix and loop structures for the NTE that makes multiple mito-specific interactions with functionally critical regions of the mitoribosome. These include ribosomal RNA segments that constitute the peptidyl transferase center (PTC) and those that connect PTC with the GTPase-associated center and with mitoribosomal proteins L16 and L27. Our structure reveals the presence of a tRNA in the pe/E position and a rotation of the small mitoribosomal subunit on RRFmt binding. In addition, we observe an interaction between the pe/E tRNA and a mito-specific protein, mL64. These findings help understand the unique features of mitoribosome recycling.
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25
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Abstract
This review summarizes our current understanding of translation in prokaryotes, focusing on the mechanistic and structural aspects of each phase of translation: initiation, elongation, termination, and ribosome recycling. The assembly of the initiation complex provides multiple checkpoints for messenger RNA (mRNA) and start-site selection. Correct codon-anticodon interaction during the decoding phase of elongation results in major conformational changes of the small ribosomal subunit and shapes the reaction pathway of guanosine triphosphate (GTP) hydrolysis. The ribosome orchestrates proton transfer during peptide bond formation, but requires the help of elongation factor P (EF-P) when two or more consecutive Pro residues are to be incorporated. Understanding the choreography of transfer RNA (tRNA) and mRNA movements during translocation helps to place the available structures of translocation intermediates onto the time axis of the reaction pathway. The nascent protein begins to fold cotranslationally, in the constrained space of the polypeptide exit tunnel of the ribosome. When a stop codon is reached at the end of the coding sequence, the ribosome, assisted by termination factors, hydrolyzes the ester bond of the peptidyl-tRNA, thereby releasing the nascent protein. Following termination, the ribosome is dissociated into subunits and recycled into another round of initiation. At each step of translation, the ribosome undergoes dynamic fluctuations between different conformation states. The aim of this article is to show the link between ribosome structure, dynamics, and function.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen 37077, Germany
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26
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Graf M, Huter P, Maracci C, Peterek M, Rodnina MV, Wilson DN. Visualization of translation termination intermediates trapped by the Apidaecin 137 peptide during RF3-mediated recycling of RF1. Nat Commun 2018; 9:3053. [PMID: 30076302 PMCID: PMC6076264 DOI: 10.1038/s41467-018-05465-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/06/2018] [Indexed: 12/20/2022] Open
Abstract
During translation termination in bacteria, the release factors RF1 and RF2 are recycled from the ribosome by RF3. While high-resolution structures of the individual termination factors on the ribosome exist, direct structural insight into how RF3 mediates dissociation of the decoding RFs has been lacking. Here we have used the Apidaecin 137 peptide to trap RF1 together with RF3 on the ribosome and visualize an ensemble of termination intermediates using cryo-electron microscopy. Binding of RF3 to the ribosome induces small subunit (SSU) rotation and swivelling of the head, yielding intermediate states with shifted P-site tRNAs and RF1 conformations. RF3 does not directly eject RF1 from the ribosome, but rather induces full rotation of the SSU that indirectly dislodges RF1 from its binding site. SSU rotation is coupled to the accommodation of the GTPase domain of RF3 on the large subunit (LSU), thereby promoting GTP hydrolysis and dissociation of RF3 from the ribosome. In bacteria, the process of translation termination is performed by three termination release factors RF1, RF2 and RF3. Here the authors provide detailed structural insights into the mechanism by which RF1 is dissociated from the ribosome by RF3 during termination.
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Affiliation(s)
- Michael Graf
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Paul Huter
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Cristina Maracci
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, 37077, Germany
| | - Miroslav Peterek
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, 37077, Germany
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
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27
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Ayyub SA, Lahry K, Dobriyal D, Mondal S, Varshney U. Antimicrobial activity of fusidic acid in Escherichia coli is dependent on the relative levels of ribosome recycling factor and elongation factor G. FEMS Microbiol Lett 2018; 365:5004850. [PMID: 29846570 DOI: 10.1093/femsle/fny133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/23/2018] [Indexed: 11/14/2022] Open
Abstract
During protein synthesis, elongation factor G (EFG) participates at the steps of translocation and ribosome recycling. Fusidic acid (FA) is a bacteriostatic antibiotic, which traps EFG on ribosomes, stalling them on mRNAs. How the bacterial susceptibility to FA is determined, and which of the two functions of EFG (translocation or ribosome recycling) is more vulnerable, has remained debatable. The in vivo studies addressing these aspects of FA mediated inhibition of protein synthesis are lacking. Here, we used a system of Escherichia coli strains and their complementation/supplementation with the plasmid borne copies of the inducible versions of EFG and ribosome recycling factor (RRF) genes. Additionally, we investigated FA sensitivity in a strain with increased proportion of stalled ribosomes. We show that the cells with high EFG/RRF (or low RRF/EFG) ratios are more susceptible to FA than those with low EFG/RRF (or high RRF/EFG) ratios. Our in vivo observations are consistent with the recent in vitro reports of dependence of FA susceptibility on EFG/RRF ratios, and the notion that an overriding target of FA is the translocation function of EFG. An applied outcome of our in vivo study is that FA mediated growth inhibition could be facilitated by depletion or inactivation of cellular RRF.
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Affiliation(s)
- Shreya Ahana Ayyub
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Kuldeep Lahry
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Divya Dobriyal
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Sanjay Mondal
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, 560064
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28
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Polikanov YS, Aleksashin NA, Beckert B, Wilson DN. The Mechanisms of Action of Ribosome-Targeting Peptide Antibiotics. Front Mol Biosci 2018; 5:48. [PMID: 29868608 PMCID: PMC5960728 DOI: 10.3389/fmolb.2018.00048] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022] Open
Abstract
The ribosome is one of the major targets in the cell for clinically used antibiotics. However, the increase in multidrug resistant bacteria is rapidly reducing the effectiveness of our current arsenal of ribosome-targeting antibiotics, highlighting the need for the discovery of compounds with new scaffolds that bind to novel sites on the ribosome. One possible avenue for the development of new antimicrobial agents is by characterization and optimization of ribosome-targeting peptide antibiotics. Biochemical and structural data on ribosome-targeting peptide antibiotics illustrates the large diversity of scaffolds, binding interactions with the ribosome as well as mechanism of action to inhibit translation. The availability of high-resolution structures of ribosomes in complex with peptide antibiotics opens the way to structure-based design of these compounds as novel antimicrobial agents.
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Affiliation(s)
- Yury S Polikanov
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL, United States
| | - Nikolay A Aleksashin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Bertrand Beckert
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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Janiak A, Kwasniewski M, Sowa M, Gajek K, Żmuda K, Kościelniak J, Szarejko I. No Time to Waste: Transcriptome Study Reveals that Drought Tolerance in Barley May Be Attributed to Stressed-Like Expression Patterns that Exist before the Occurrence of Stress. FRONTIERS IN PLANT SCIENCE 2018; 8:2212. [PMID: 29375595 PMCID: PMC5767312 DOI: 10.3389/fpls.2017.02212] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/18/2017] [Indexed: 05/24/2023]
Abstract
Plant survival in adverse environmental conditions requires a substantial change in the metabolism, which is reflected by the extensive transcriptome rebuilding upon the occurrence of the stress. Therefore, transcriptomic studies offer an insight into the mechanisms of plant stress responses. Here, we present the results of global gene expression profiling of roots and leaves of two barley genotypes with contrasting ability to cope with drought stress. Our analysis suggests that drought tolerance results from a certain level of transcription of stress-influenced genes that is present even before the onset of drought. Genes that predispose the plant to better drought survival play a role in the regulatory network of gene expression, including several transcription factors, translation regulators and structural components of ribosomes. An important group of genes is involved in signaling mechanisms, with significant contribution of hormone signaling pathways and an interplay between ABA, auxin, ethylene and brassinosteroid homeostasis. Signal transduction in a drought tolerant genotype may be more efficient through the expression of genes required for environmental sensing that are active already during normal water availability and are related to actin filaments and LIM domain proteins, which may function as osmotic biosensors. Better survival of drought may also be attributed to more effective processes of energy generation and more efficient chloroplasts biogenesis. Interestingly, our data suggest that several genes involved in a photosynthesis process are required for the establishment of effective drought response not only in leaves, but also in roots of barley. Thus, we propose a hypothesis that root plastids may turn into the anti-oxidative centers protecting root macromolecules from oxidative damage during drought stress. Specific genes and their potential role in building up a drought-tolerant barley phenotype is extensively discussed with special emphasis on processes that take place in barley roots. When possible, the interconnections between particular factors are emphasized to draw a broader picture of the molecular mechanisms of drought tolerance in barley.
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Affiliation(s)
- Agnieszka Janiak
- Department of Genetics, University of Silesia in Katowice, Katowice, Poland
| | - Miroslaw Kwasniewski
- Centre for Bioinformatics and Data Analysis, Medical University of Bialystok, Bialystok, Poland
| | - Marta Sowa
- Department of Plant Anatomy and Cytology, University of Silesia in Katowice, Katowice, Poland
| | - Katarzyna Gajek
- Department of Genetics, University of Silesia in Katowice, Katowice, Poland
| | - Katarzyna Żmuda
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture of Krakow, Kraków, Poland
| | - Janusz Kościelniak
- Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture of Krakow, Kraków, Poland
| | - Iwona Szarejko
- Department of Genetics, University of Silesia in Katowice, Katowice, Poland
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30
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Silva AF, dos Santos AR, Coelho Trevisan DA, Ribeiro AB, Zanetti Campanerut-Sá PA, Kukolj C, de Souza EM, Cardoso RF, Estivalet Svidzinski TI, de Abreu Filho BA, Junior MM, Graton Mikcha JM. Cinnamaldehyde induces changes in the protein profile of Salmonella Typhimurium biofilm. Res Microbiol 2018; 169:33-43. [DOI: 10.1016/j.resmic.2017.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 01/03/2023]
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31
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Chen Y, Kaji A, Kaji H, Cooperman BS. The kinetic mechanism of bacterial ribosome recycling. Nucleic Acids Res 2017; 45:10168-10177. [PMID: 28973468 PMCID: PMC5737721 DOI: 10.1093/nar/gkx694] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/26/2017] [Indexed: 02/06/2023] Open
Abstract
Bacterial ribosome recycling requires breakdown of the post-termination complex (PoTC), comprising a messenger RNA (mRNA) and an uncharged transfer RNA (tRNA) cognate to the terminal mRNA codon bound to the 70S ribosome. The translation factors, elongation factor G and ribosome recycling factor, are known to be required for recycling, but there is controversy concerning whether these factors act primarily to effect the release of mRNA and tRNA from the ribosome, with the splitting of the ribosome into subunits being somewhat dispensable, or whether their main function is to catalyze the splitting reaction, which necessarily precedes mRNA and tRNA release. Here, we utilize three assays directly measuring the rates of mRNA and tRNA release and of ribosome splitting in several model PoTCs. Our results largely reconcile these previously held views. We demonstrate that, in the absence of an upstream Shine–Dalgarno (SD) sequence, PoTC breakdown proceeds in the order: mRNA release followed by tRNA release and then by 70S splitting. By contrast, in the presence of an SD sequence all three processes proceed with identical apparent rates, with the splitting step likely being rate-determining. Our results are consistent with ribosome profiling results demonstrating the influence of upstream SD-like sequences on ribosome occupancy at or just before the mRNA stop codon.
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Affiliation(s)
- Yuanwei Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Akira Kaji
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hideko Kaji
- Department of Biochemistry and Molecular Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19137, USA
| | - Barry S Cooperman
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
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32
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Sousa JR, Silveira CM, Fontes P, Roma-Rodrigues C, Fernandes AR, Van Driessche G, Devreese B, Moura I, Moura JJ, Almeida MG. Understanding the response of Desulfovibrio desulfuricans ATCC 27774 to the electron acceptors nitrate and sulfate - biosynthetic costs modulate substrate selection. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1455-1469. [DOI: 10.1016/j.bbapap.2017.07.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 11/27/2022]
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Effect of Fusidic Acid on the Kinetics of Molecular Motions During EF-G-Induced Translocation on the Ribosome. Sci Rep 2017; 7:10536. [PMID: 28874811 PMCID: PMC5585275 DOI: 10.1038/s41598-017-10916-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/16/2017] [Indexed: 11/08/2022] Open
Abstract
The translocation step of protein synthesis entails binding and dissociation of elongation factor G (EF-G), movements of the two tRNA molecules, and motions of the ribosomal subunits. The translocation step is targeted by many antibiotics. Fusidic acid (FA), an antibiotic that blocks EF-G on the ribosome, may also interfere with some of the ribosome rearrangements, but the exact timing of inhibition remains unclear. To follow in real-time the dynamics of the ribosome–tRNA–EF-G complex, we have developed a fluorescence toolbox which allows us to monitor the key molecular motions during translocation. Here we employed six different fluorescence observables to investigate how FA affects translocation kinetics. We found that FA binds to an early translocation intermediate, but its kinetic effect on tRNA movement is small. FA does not affect the synchronous forward (counterclockwise) movements of the head and body domains of the small ribosomal subunit, but exerts a strong effect on the rates of late translocation events, i.e. backward (clockwise) swiveling of the head domain and the transit of deacylated tRNA through the E′ site, in addition to blocking EF-G dissociation. The use of ensemble kinetics and numerical integration unraveled how the antibiotic targets molecular motions within the ribosome-EF-G complex.
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34
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Yang SC, Yen FL, Wang PW, Aljuffali IA, Weng YH, Tseng CH, Fang JY. Naphtho[1,2-b]furan-4,5-dione is a potent anti-MRSA agent against planktonic, biofilm and intracellular bacteria. Future Microbiol 2017; 12:1059-1073. [DOI: 10.2217/fmb-2017-0044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Aim: Naphtho[1,2-b]furan-4,5-dione (N12D) and naphtho[2,3-b]furan-4,9-dione (N23D) are furanonaphthoquinone derivatives from natural resources. We examined the antimicrobial activity of N12D and N23D against drug-resistant Staphylococcus aureus. Materials & methods: Minimum inhibitory concentration, minimum bactericidal concentration, bacterial viability and agar diffusion assay were conducted against methicillin-resistant S. aureus (MRSA) and clinical isolates of vancomycin-resistant S. aureus. Results & conclusion: The minimum inhibitory concentration of N12D and N23D against MRSA was 4.9–9.8 and 39 μM, respectively. With regard to the agar diffusion test, the inhibition zone of the quinone compounds was threefold larger than that of oxacillin. N12D was found to inhibit MRSA biofilm thickness from 24 to 16 μm as observed by confocal microscopy. N12D showed a significant reduction of the intracellular MRSA burden without decreasing the macrophage viability. The antibacterial mechanisms of N12D may be bacterial wall/membrane damage and disturbance of gluconeogenesis and the tricarboxylic acid cycle.
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Affiliation(s)
- Shih-Chun Yang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan 333, Taiwan
| | - Feng-Lin Yen
- Department of Fragrance & Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Pei-Wen Wang
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan
| | - Ibrahim A Aljuffali
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Yi-Han Weng
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan 333, Taiwan
| | - Chih-Hua Tseng
- Department of Fragrance & Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Research Center for Natural Products & Drug Development, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Center for Infectious Disease & Cancer Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Jia-You Fang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan 333, Taiwan
- Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan 333, Taiwan
- Research Center for Food & Cosmetic Safety & Research Center for Chinese Herbal Medicine, Chang Gung University of Science & Technology, Taoyuan 333, Taiwan
- Department of Anesthesiology, Chang Gung Memorial Hospital, Kweishan, Taoyuan 333, Taiwan
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35
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Yang SC, Tseng CH, Wang PW, Lu PL, Weng YH, Yen FL, Fang JY. Pterostilbene, a Methoxylated Resveratrol Derivative, Efficiently Eradicates Planktonic, Biofilm, and Intracellular MRSA by Topical Application. Front Microbiol 2017; 8:1103. [PMID: 28659908 PMCID: PMC5468402 DOI: 10.3389/fmicb.2017.01103] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/31/2017] [Indexed: 12/23/2022] Open
Abstract
Pterostilbene is a methoxylated derivative of resveratrol originated from natural sources. We investigated the antibacterial activity of pterostilbene against drug-resistant Staphylococcus aureus and the feasibility of using it to treat cutaneous bacteria. The antimicrobial effect was evaluated using an in vitro culture model and an in vivo mouse model of cutaneous infection. The minimum inhibitory concentration (MIC) assay demonstrated a superior biocidal activity of pterostilbene compared to resveratrol (8~16-fold) against methicillin-resistant S. aureus (MRSA) and clinically isolated vancomycin-intermediate S. aureus (VISA). Pterostilbene was found to reduce MRSA biofilm thickness from 18 to 10 μm as detected by confocal microscopy. Pterostilbene showed minimal toxicity to THP-1 cells and was readily engulfed by the macrophages, facilitating the eradication of intracellular MRSA. Pterostilbene exhibited increased skin absorption over resveratrol by 6-fold. Topical pterostilbene application improved the abscess formation produced by MRSA by reducing the bacterial burden and ameliorating the skin architecture. The potent anti-MRSA capability of pterostilbene was related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation. This mechanism of action was different from that of resveratrol according to proteomic analysis and molecular docking. Pterostilbene has the potential to serve as a novel class of topically applied agents for treating MRSA infection in the skin while demonstrating less toxicity to mammalian cells.
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Affiliation(s)
- Shih-Chun Yang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan
| | - Chih-Hua Tseng
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Research Center for Natural Products and Drug Development, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Center for Infectious Disease and Cancer Research, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan
| | - Pei-Wen Wang
- Department of Medical Research, China Medical University Hospital, China Medical UniversityTaichung, Taiwan
| | - Po-Liang Lu
- Department of Internal Medicine, Kaohsiung Medical University HospitalKaohsiung, Taiwan.,College of Medicine, Kaohsiung Medical UniversityKaohsiung, Taiwan
| | - Yi-Han Weng
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan
| | - Feng-Lin Yen
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen UniversityKaohsiung, Taiwan
| | - Jia-You Fang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan.,Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and TechnologyTaoyuan, Taiwan.,Department of Anesthesiology, Chang Gung Memorial HospitalTaoyuan, Taiwan
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36
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Iwakura N, Yokoyama T, Quaglia F, Mitsuoka K, Mio K, Shigematsu H, Shirouzu M, Kaji A, Kaji H. Chemical and structural characterization of a model Post-Termination Complex (PoTC) for the ribosome recycling reaction: Evidence for the release of the mRNA by RRF and EF-G. PLoS One 2017; 12:e0177972. [PMID: 28542628 PMCID: PMC5443523 DOI: 10.1371/journal.pone.0177972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 05/06/2017] [Indexed: 12/02/2022] Open
Abstract
A model Post-Termination Complex (PoTC) used for the discovery of Ribosome Recycling Factor (RRF) was purified and characterized by cryo-electron microscopic analysis and biochemical methods. We established that the model PoTC has mostly one tRNA, at the P/E or P/P position, together with one mRNA. The structural studies were supported by the biochemical measurement of bound tRNA and mRNA. Using this substrate, we establish that the release of tRNA, release of mRNA and splitting of ribosomal subunits occur during the recycling reaction. Order of these events is tRNA release first followed by mRNA release and splitting almost simultaneously. Moreover, we demonstrate that IF3 is not involved in any of the recycling reactions but simply prevents the re-association of split ribosomal subunits. Our finding demonstrates that the important function of RRF includes the release of mRNA, which is often missed by the use of a short ORF with the Shine-Dalgarno sequence near the termination site.
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Affiliation(s)
- Nobuhiro Iwakura
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania, United States of America
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Takeshi Yokoyama
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Yokohama, Japan
| | - Fabio Quaglia
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania, United States of America
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- University of Camerino, School of Biosciences and Veterinary Medicine, Camerino, Italy
| | - Kaoru Mitsuoka
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan
| | - Kazuhiro Mio
- Molecular Profiling Research Center for Drug Discovery and OPERANDO Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Hideki Shigematsu
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Yokohama, Japan
| | - Mikako Shirouzu
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Yokohama, Japan
| | - Akira Kaji
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HK); (AK)
| | - Hideko Kaji
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HK); (AK)
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37
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Abouelfetouh A, Kassem M, Naguib M, El-Nakeeb M. Investigation and Treatment of Fusidic Acid Resistance Among Methicillin-Resistant Staphylococcal Isolates from Egypt. Microb Drug Resist 2017; 23:8-17. [DOI: 10.1089/mdr.2015.0336] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Alaa Abouelfetouh
- Department of Microbiology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Mervat Kassem
- Department of Microbiology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Marwa Naguib
- Department of Microbiology, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
| | - Moustafa El-Nakeeb
- Department of Microbiology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
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38
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Key Intermediates in Ribosome Recycling Visualized by Time-Resolved Cryoelectron Microscopy. Structure 2016; 24:2092-2101. [PMID: 27818103 DOI: 10.1016/j.str.2016.09.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/21/2016] [Accepted: 10/07/2016] [Indexed: 11/20/2022]
Abstract
Upon encountering a stop codon on mRNA, polypeptide synthesis on the ribosome is terminated by release factors, and the ribosome complex, still bound with mRNA and P-site-bound tRNA (post-termination complex, PostTC), is split into ribosomal subunits, ready for a new round of translational initiation. Separation of post-termination ribosomes into subunits, or "ribosome recycling," is promoted by the joint action of ribosome-recycling factor (RRF) and elongation factor G (EF-G) in a guanosine triphosphate (GTP) hydrolysis-dependent manner. Here we used a mixing-spraying-based method of time-resolved cryo-electron microscopy (cryo-EM) to visualize the short-lived intermediates of the recycling process. The two complexes that contain (1) both RRF and EF-G bound to the PostTC or (2) deacylated tRNA bound to the 30S subunit are of particular interest. Our observations of the native form of these complexes demonstrate the strong potential of time-resolved cryo-EM for visualizing previously unobservable transient structures.
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39
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Belardinelli R, Sharma H, Peske F, Wintermeyer W, Rodnina MV. Translocation as continuous movement through the ribosome. RNA Biol 2016; 13:1197-1203. [PMID: 27801619 DOI: 10.1080/15476286.2016.1240140] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In each round of translation elongation, tRNAs and mRNA move within the ribosome by one codon at a time. tRNA-mRNA translocation is promoted by elongation factor G (EF-G) at the cost of GTP hydrolysis. The key questions for understanding translocation are how and when the tRNAs move and how EF-G coordinates motions of the ribosomal subunits with tRNA movement. Here we present 2 recent papers which describe the choreography of movements over the whole trajectory of translocation. We present the view that EF-G accelerates translocation by promoting the steps that lead to GTPase-dependent ribosome unlocking. EF-G facilitates the formation of the rotated state of the ribosome and uncouples the backward motions of the ribosomal subunits, forming an open conformation in which the tRNAs can rapidly move. Ribosome dynamics are important not only in translocation, but also in recoding events, such as frameshifting and bypassing, and mediate sensitivity to antibiotics.
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Affiliation(s)
- Riccardo Belardinelli
- a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany
| | - Heena Sharma
- a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany
| | - Frank Peske
- a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany
| | - Wolfgang Wintermeyer
- a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany
| | - Marina V Rodnina
- a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany
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40
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Arenz S, Wilson DN. Bacterial Protein Synthesis as a Target for Antibiotic Inhibition. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025361. [PMID: 27481773 DOI: 10.1101/cshperspect.a025361] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein synthesis occurs on macromolecular machines, called ribosomes. Bacterial ribosomes and the translational machinery represent one of the major targets for antibiotics in the cell. Therefore, structural and biochemical investigations into ribosome-targeting antibiotics provide not only insight into the mechanism of action and resistance of antibiotics, but also insight into the fundamental process of protein synthesis. This review summarizes the recent advances in our understanding of protein synthesis, particularly with respect to X-ray and cryoelectron microscopy (cryo-EM) structures of ribosome complexes, and highlights the different steps of translation that are targeted by the diverse array of known antibiotics. Such findings will be important for the ongoing development of novel and improved antimicrobial agents to combat the rapid emergence of multidrug resistant pathogenic bacteria.
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Affiliation(s)
- Stefan Arenz
- Center for Integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany
| | - Daniel N Wilson
- Center for Integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany Gene Center and Department for Biochemistry, University of Munich, 81377 Munich, Germany
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41
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Magalhães P, Pinto L, Gonçalves A, Araújo JE, Santos HM, Capelo JL, Saénz Y, de Toro M, Torres C, Chambon C, Hébraud M, Poeta P, Igrejas G. Could transformation mechanisms of acetylase-harboring pMdT1 plasmid be evaluated through proteomic tools in Escherichia coli? J Proteomics 2016; 145:103-111. [PMID: 27072110 DOI: 10.1016/j.jprot.2016.03.042] [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: 02/15/2016] [Revised: 03/22/2016] [Accepted: 03/29/2016] [Indexed: 11/19/2022]
Abstract
UNLABELLED Escherichia coli is a commensal microorganism of the gastrointestinal tract of animals and humans and it is an excellent model organism for the study of antibiotic resistance mechanisms. The resistance transmission and other characteristics of bacteria are based on different types of gene transfer occurring throughout the bacterial evolution. One of which is horizontal gene transfer that allows us to understand the ability of bacteria to acquire new genes. One dimensional and two dimensional electrophoresis (2-DE) techniques were performed in order to identify and characterize the proteome of two E. coli strains: Electromax DH10B, a transformation-ready strain; and TF-Se20, the Electromax DH10B that contains the aac(6')-Ib-cr4-harboring pMdT1 plasmid. After 2-DE and subsequent analysis by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), it was possible to identify 76 distinct proteins on the TF-Se20 strain, whereas 71 had a known function. From Electromax DH10B strain, 72 different proteins were identified of which 71 were associated with a biological process. The protein of interest, aminoglycoside N-(6')-acetyltransferase type 1, was identified by MALDI-TOF MS. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique was performed to determine its sequence. Seventy six percent of the acetylase sequence was reconstructed only in the TF-Se20 strain, representing the single protein associated to antibiotic resistance. MALDI-TOF MS and LC-MS/MS approaches allowed us to determine the total proteome of both strains, as well as the acetylase sequence. Both of them enhance the ability to obtain more accurate information about the mechanisms of antimicrobial resistance. The pMdT1 plasmid brings a new perspective in understanding the metabolic processes that lead to antibiotic resistance. BIOLOGICAL SIGNIFICANCE This study highlights the importance of proteomics and bioinformatics in understanding mechanisms of gene transfer and antibiotic resistance. These two approaches allow to compare the protein expression in different samples, as well as different biological processes related to each protein.
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Affiliation(s)
- Pedro Magalhães
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Luís Pinto
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Alexandre Gonçalves
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - José Eduardo Araújo
- UCIBIO-REQUIMTE, Faculty of Science and Technology, University NOVA of Lisbon, Caparica, Portugal
| | - Hugo M Santos
- UCIBIO-REQUIMTE, Faculty of Science and Technology, University NOVA of Lisbon, Caparica, Portugal; ProteoMass Scientific Society, Faculty of Sciences and Technology, Caparica, Portugal
| | - José Luis Capelo
- UCIBIO-REQUIMTE, Faculty of Science and Technology, University NOVA of Lisbon, Caparica, Portugal; ProteoMass Scientific Society, Faculty of Sciences and Technology, Caparica, Portugal
| | - Yolanda Saénz
- Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | - María de Toro
- Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain; Instituto de Biomedicina y Biotecnologia de Cantabria IBBTEC, Universidad de Cantabria/CSIC, Santander, Spain
| | - Carmen Torres
- Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain; Department of Food and Agriculture, Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Christophe Chambon
- Institut National de la Recherche Agronomique, Centre Auvergne-Rhône-Alpes, Plate-Forme d'Exploration du Métabolisme composante protéomique (PFEMcp), France
| | - Michel Hébraud
- Institut National de la Recherche Agronomique, Centre Auvergne-Rhône-Alpes, Plate-Forme d'Exploration du Métabolisme composante protéomique (PFEMcp), France; Institut National de la Recherche Agronomique, Centre Auvergne-Rhône-Alpes, UR454 Microbiologie, France
| | - Patrícia Poeta
- UCIBIO-REQUIMTE, Faculty of Science and Technology, University NOVA of Lisbon, Caparica, Portugal; Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Gilberto Igrejas
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; UCIBIO-REQUIMTE, Faculty of Science and Technology, University NOVA of Lisbon, Caparica, Portugal.
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42
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Ero R, Kumar V, Chen Y, Gao YG. Similarity and diversity of translational GTPase factors EF-G, EF4, and BipA: From structure to function. RNA Biol 2016; 13:1258-1273. [PMID: 27325008 PMCID: PMC5207388 DOI: 10.1080/15476286.2016.1201627] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
EF-G, EF4, and BipA are members of the translation factor family of GTPases with a common ribosome binding mode and GTPase activation mechanism. However, topological variations of shared as well as unique domains ensure different roles played by these proteins during translation. Recent X-ray crystallography and cryo-electron microscopy studies have revealed the structural basis for the involvement of EF-G domain IV in securing the movement of tRNAs and mRNA during translocation as well as revealing how the unique C-terminal domains of EF4 and BipA interact with the ribosome and tRNAs contributing to the regulation of translation under certain conditions. EF-G, EF-4, and BipA are intriguing examples of structural variations on a common theme that results in diverse behavior and function. Structural studies of translational GTPase factors have been greatly facilitated by the use of antibiotics, which have revealed their mechanism of action.
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Affiliation(s)
- Rya Ero
- a School of Biological Sciences , Nanyang Technological University , Singapore
| | - Veerendra Kumar
- a School of Biological Sciences , Nanyang Technological University , Singapore.,b Institute of Molecular and Cell Biology, A*STAR , Singapore
| | - Yun Chen
- a School of Biological Sciences , Nanyang Technological University , Singapore
| | - Yong-Gui Gao
- a School of Biological Sciences , Nanyang Technological University , Singapore.,b Institute of Molecular and Cell Biology, A*STAR , Singapore
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43
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Salsi E, Farah E, Ermolenko DN. EF-G Activation by Phosphate Analogs. J Mol Biol 2016; 428:2248-58. [PMID: 27063503 DOI: 10.1016/j.jmb.2016.03.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 01/31/2023]
Abstract
Elongation factor G (EF-G) is a universally conserved translational GTPase that promotes the translocation of tRNA and mRNA through the ribosome. EF-G binds to the ribosome in a GTP-bound form and subsequently catalyzes GTP hydrolysis. The contribution of the ribosome-stimulated GTP hydrolysis by EF-G to tRNA/mRNA translocation remains debated. Here, we show that while EF-G•GDP does not stably bind to the ribosome and induce translocation, EF-G•GDP in complex with phosphate group analogs BeF3(-) and AlF4(-) promotes the translocation of tRNA and mRNA. Furthermore, the rates of mRNA translocation induced by EF-G in the presence of GTP and a non-hydrolyzable analog of GTP, GDP•BeF3(-) are similar. Our results are consistent with the model suggesting that GTP hydrolysis is not directly coupled to mRNA/tRNA translocation. Hence, GTP binding is required to induce the activated, translocation-competent conformation of EF-G while GTP hydrolysis triggers EF-G release from the ribosome.
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Affiliation(s)
- Enea Salsi
- Department of Biochemistry and Biophysics & Center for RNA Biology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Elie Farah
- Department of Biochemistry and Biophysics & Center for RNA Biology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Dmitri N Ermolenko
- Department of Biochemistry and Biophysics & Center for RNA Biology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
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44
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Borg A, Pavlov M, Ehrenberg M. Mechanism of fusidic acid inhibition of RRF- and EF-G-dependent splitting of the bacterial post-termination ribosome. Nucleic Acids Res 2016; 44:3264-75. [PMID: 27001509 PMCID: PMC4838388 DOI: 10.1093/nar/gkw178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/07/2016] [Indexed: 01/13/2023] Open
Abstract
The antibiotic drug fusidic acid (FA) is commonly used in the clinic against gram-positive bacterial infections. FA targets ribosome-bound elongation factor G (EF-G), a translational GTPase that accelerates both messenger RNA (mRNA) translocation and ribosome recycling. How FA inhibits translocation was recently clarified, but FA inhibition of ribosome recycling by EF-G and ribosome recycling factor (RRF) has remained obscure. Here we use fast kinetics techniques to estimate mean times of ribosome splitting and the stoichiometry of GTP hydrolysis by EF-G at varying concentrations of FA, EF-G and RRF. These mean times together with previous data on uninhibited ribosome recycling were used to clarify the mechanism of FA inhibition of ribosome splitting. The biochemical data on FA inhibition of translocation and recycling were used to model the growth inhibitory effect of FA on bacterial populations. We conclude that FA inhibition of translocation provides the dominant cause of bacterial growth reduction, but that FA inhibition of ribosome recycling may contribute significantly to FA-induced expression of short regulatory open reading frames, like those involved in FA resistance.
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Affiliation(s)
- Anneli Borg
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, 75124 Uppsala, Sweden
| | - Michael Pavlov
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, 75124 Uppsala, Sweden
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, 75124 Uppsala, Sweden
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45
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Multiperspective smFRET reveals rate-determining late intermediates of ribosomal translocation. Nat Struct Mol Biol 2016; 23:333-41. [PMID: 26926435 PMCID: PMC4821728 DOI: 10.1038/nsmb.3177] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 01/25/2016] [Indexed: 12/04/2022]
Abstract
Directional translocation of the ribosome through the messenger RNA open reading frame is a critical determinant of translational fidelity. This process entails a complex interplay of large-scale conformational changes within the actively translating particle, which together coordinate the movement of transfer and messenger RNA substrates with respect to the large and small ribosomal subunits. Using pre-steady state, single-molecule fluorescence resonance energy transfer imaging, we have tracked the nature and timing of these conformational events within the Escherichia coli ribosome from five structural perspectives. Our investigations reveal direct evidence of structurally and kinetically distinct, late intermediates during substrate movement, whose resolution is rate-determining to the translocation mechanism. These steps involve intra-molecular events within the EFG(GDP)-bound ribosome, including exaggerated, reversible fluctuations of the small subunit head domain, which ultimately facilitate peptidyl-tRNA’s movement into its final post-translocation position.
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46
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Liu Q, Fredrick K. Intersubunit Bridges of the Bacterial Ribosome. J Mol Biol 2016; 428:2146-64. [PMID: 26880335 DOI: 10.1016/j.jmb.2016.02.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/29/2016] [Accepted: 02/05/2016] [Indexed: 02/02/2023]
Abstract
The ribosome is a large two-subunit ribonucleoprotein machine that translates the genetic code in all cells, synthesizing proteins according to the sequence of the mRNA template. During translation, the primary substrates, transfer RNAs, pass through binding sites formed between the two subunits. Multiple interactions between the ribosomal subunits, termed intersubunit bridges, keep the ribosome intact and at the same time govern dynamics that facilitate the various steps of translation such as transfer RNA-mRNA movement. Here, we review the molecular nature of these intersubunit bridges, how they change conformation during translation, and their functional roles in the process.
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Affiliation(s)
- Qi Liu
- Ohio State Biochemistry Program, Department of Microbiology, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Kurt Fredrick
- Ohio State Biochemistry Program, Department of Microbiology, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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47
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Fernandes P. Fusidic Acid: A Bacterial Elongation Factor Inhibitor for the Oral Treatment of Acute and Chronic Staphylococcal Infections. Cold Spring Harb Perspect Med 2016; 6:a025437. [PMID: 26729758 DOI: 10.1101/cshperspect.a025437] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Fusidic acid is an oral antistaphylococcal antibiotic that has been used in Europe for more than 40 years to treat skin infections as well as chronic bone and joint infections. It is a steroidal antibiotic and the only marketed member of the fusidane class. Fusidic acid inhibits protein synthesis by binding EF-G-GDP, which results in the inhibition of both peptide translocation and ribosome disassembly. It has a novel structure and novel mode of action and, therefore, there is little cross-resistance with other known antibiotics. Many mutations can occur in the FusA gene that codes for EF-G, and some of these mutations can result in high-level resistance (minimum inhibitory concentration [MIC] > 64 mg/L), whereas others result in biologically unfit staphylococci that require compensatory mutations to survive. Low-level resistance (<8 mg/L) is more common and is mediated by fusB, fusC, and fusD genes that code for small proteins that protect EF-G-GDP from binding fusidic acid. The genes for these proteins are spread by plasmids and can be selected mostly by topical antibiotic use. Reports of resistance have led to combination use of fusidic acid with rifampin, which is superseded by the development of a new dosing regimen for fusidic acid that can be used in monotherapy. It consists of a front-loading dose to decrease the potential for resistance development followed by a maintenance dose. This dosing regimen is now being used in clinical trials in the United States for skin and refractory bone and joint infections.
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48
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Borg A, Pavlov M, Ehrenberg M. Complete kinetic mechanism for recycling of the bacterial ribosome. RNA (NEW YORK, N.Y.) 2016; 22:10-21. [PMID: 26527791 PMCID: PMC4691825 DOI: 10.1261/rna.053157.115] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/03/2015] [Indexed: 05/05/2023]
Abstract
How EF-G and RRF act together to split a post-termination ribosomal complex into its subunits has remained obscure. Here, using stopped-flow experiments with Rayleigh light scattering detection and quench-flow experiments with radio-detection of GTP hydrolysis, we have clarified the kinetic mechanism of ribosome recycling and obtained precise estimates of its kinetic parameters. Ribosome splitting requires that EF-G binds to an already RRF-containing ribosome. EF-G binding to RRF-free ribosomes induces futile rounds of GTP hydrolysis and inhibits ribosome splitting, implying that while RRF is purely an activator of recycling, EF-G acts as both activator and competitive inhibitor of RRF in recycling of the post-termination ribosome. The ribosome splitting rate and the number of GTPs consumed per splitting event depend strongly on the free concentrations of EF-G and RRF. The maximal recycling rate, here estimated as 25 sec(-1), is approached at very high concentrations of EF-G and RRF with RRF in high excess over EF-G. The present in vitro results, suggesting an in vivo ribosome recycling rate of ∼5 sec(-1), are discussed in the perspective of rapidly growing bacterial cells.
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Affiliation(s)
- Anneli Borg
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, 751 24 Uppsala, Sweden
| | - Michael Pavlov
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, 751 24 Uppsala, Sweden
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, 751 24 Uppsala, Sweden
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49
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Koripella RK, Holm M, Dourado D, Mandava CS, Flores S, Sanyal S. A conserved histidine in switch-II of EF-G moderates release of inorganic phosphate. Sci Rep 2015; 5:12970. [PMID: 26264741 PMCID: PMC4532990 DOI: 10.1038/srep12970] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/13/2015] [Indexed: 01/13/2023] Open
Abstract
Elongation factor G (EF-G), a translational GTPase responsible for tRNA-mRNA translocation possesses a conserved histidine (H91 in Escherichia coli) at the apex of switch-II, which has been implicated in GTPase activation and GTP hydrolysis. While H91A, H91R and H91E mutants showed different degrees of defect in ribosome associated GTP hydrolysis, H91Q behaved like the WT. However, all these mutants, including H91Q, are much more defective in inorganic phosphate (Pi) release, thereby suggesting that H91 facilitates Pi release. In crystal structures of the ribosome bound EF-G•GTP a tight coupling between H91 and the γ-phosphate of GTP can be seen. Following GTP hydrolysis, H91 flips ~140° in the opposite direction, probably with Pi still coupled to it. This, we suggest, promotes Pi to detach from GDP and reach the inter-domain space of EF-G, which constitutes an exit path for the Pi. Molecular dynamics simulations are consistent with this hypothesis and demonstrate a vital role of an Mg2+ ion in the process.
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Affiliation(s)
- Ravi Kiran Koripella
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
| | - Mikael Holm
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
| | - Daniel Dourado
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
| | - Chandra Sekhar Mandava
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
| | - Samuel Flores
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
| | - Suparna Sanyal
- Department of Cell and Molecular Biology, Uppsala University, Box-596, BMC, 75124, Uppsala, Sweden
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50
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Adio S, Senyushkina T, Peske F, Fischer N, Wintermeyer W, Rodnina MV. Fluctuations between multiple EF-G-induced chimeric tRNA states during translocation on the ribosome. Nat Commun 2015; 6:7442. [PMID: 26072700 PMCID: PMC4490557 DOI: 10.1038/ncomms8442] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 05/08/2015] [Indexed: 12/18/2022] Open
Abstract
The coupled translocation of transfer RNA and messenger RNA through the ribosome entails large-scale structural rearrangements, including step-wise movements of the tRNAs. Recent structural work has visualized intermediates of translocation induced by elongation factor G (EF-G) with tRNAs trapped in chimeric states with respect to 30S and 50S ribosomal subunits. The functional role of the chimeric states is not known. Here we follow the formation of translocation intermediates by single-molecule fluorescence resonance energy transfer. Using EF-G mutants, a non-hydrolysable GTP analogue, and fusidic acid, we interfere with either translocation or EF-G release from the ribosome and identify several rapidly interconverting chimeric tRNA states on the reaction pathway. EF-G engagement prevents backward transitions early in translocation and increases the fraction of ribosomes that rapidly fluctuate between hybrid, chimeric and posttranslocation states. Thus, the engagement of EF-G alters the energetics of translocation towards a flat energy landscape, thereby promoting forward tRNA movement. EF-G enhances the rate of tRNA–mRNA translocation on the ribosome. Here the authors use single-molecule FRET to follow tRNA translocation in real time, identifying new chimeric intermediates and suggesting how EF-G binding and GTP hydrolysis change the energetic landscape of translocation to accelerate forward tRNA movement.
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Affiliation(s)
- Sarah Adio
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen 37077, Germany
| | - Tamara Senyushkina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen 37077, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen 37077, Germany
| | - Niels Fischer
- 3D Electron Cryomicroscopy Group, Max Planck Institute for Biophysical Chemistry, Goettingen 37077, Germany
| | - Wolfgang Wintermeyer
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen 37077, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen 37077, Germany
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