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Yu J, Sciolino N, Breindel L, Lin Q, Burz DS, Shekhtman A. In Vivo Ribosome-Amplified MetaBOlism, RAMBO, Effect Observed by Real Time Pulse Chase, RTPC, NMR Spectroscopy. Biochemistry 2025. [PMID: 40420686 DOI: 10.1021/acs.biochem.5c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2025]
Abstract
Quinary interactions between proteins and ribosomes play an important role in regulating biological activity through a phenomenon termed the Ribosome-Amplified MetaBOlism, RAMBO, effect. This effect has been documented in vitro but not in vivo. Real time pulse chase, RTPC, NMR spectroscopy, coupled with isotopic flux analysis in Escherichia coli was used to validate the RAMBO effect in vivo. The ribosomal-targeting antibiotic chloramphenicol was employed to disrupt the quinary structure of pyruvate kinase, the final enzyme in glycolysis. Kinetic flux profiling demonstrated that the in vitro deactivation of the RAMBO effect by chloramphenicol was also observed in vivo, thereby confirming the potential role of ribosomes in regulating glycolysis. The noninvasive modular design of the RTPC-NMR platform allows for high-resolution metabolic monitoring across different cell types, providing broad applicability for studying the real-time metabolic responses to external stimuli in living cells.
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Affiliation(s)
- Jianchao Yu
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Nicholas Sciolino
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Leonard Breindel
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Qishan Lin
- RNA Epitranscriptomics & Proteomics Resource, University at Albany, State University of New York, Albany, New York 12222, United States
| | - David S Burz
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
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Chatterjee S, Maity A, Bahadur RP. Conformational switches in human RNA binding proteins involved in neurodegeneration. Biochim Biophys Acta Gen Subj 2025; 1869:130760. [PMID: 39798673 DOI: 10.1016/j.bbagen.2025.130760] [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: 09/16/2024] [Revised: 12/03/2024] [Accepted: 01/06/2025] [Indexed: 01/15/2025]
Abstract
Conformational switching in RNA binding proteins (RBPs) is crucial for regulation of RNA processing and transport. Dysregulation or mutations in RBPs and broad RNA processing abnormalities are related to many human diseases including neurodegenerative disorders. Here, we review the role of protein-RNA conformational switches in RBP-RNA complexes. RBP-RNA complexes exhibit wide range of conformational switching depending on the RNA molecule and its ability to induce conformational changes in its partner RBP. We categorize the conformational switches into three groups: rigid body, semi-flexible and full flexible. We also investigate conformational switches in large cellular assemblies including ribosome, spliceosome and RISC complexes. In addition, the role of intrinsic disorder in RBP-RNA conformational switches is discussed. We have also discussed the effect of different disease-causing mutations on conformational switching of proteins associated with neurodegenerative diseases. We believe that this study will enhance our understanding on the role of protein-RNA conformational switches. Furthermore, the availability of a large number of atomic structures of RBP-RNA complexes in near future would facilitate to create a complete repertoire of human RBP-RNA conformational switches.
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Affiliation(s)
- Sonali Chatterjee
- Computational Structural Biology Laboratory, Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Atanu Maity
- Bioinformatics Centre, Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Ranjit Prasad Bahadur
- Computational Structural Biology Laboratory, Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India; Bioinformatics Centre, Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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Goltermann L, Andersen KL, Johansen HK, Molin S, La Rosa R. Macrolide therapy in Pseudomonas aeruginosa infections causes uL4 ribosomal protein mutations leading to high-level resistance. Clin Microbiol Infect 2022; 28:1594-1601. [PMID: 35988850 DOI: 10.1016/j.cmi.2022.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/05/2022] [Accepted: 08/06/2022] [Indexed: 01/26/2023]
Abstract
OBJECTIVES Pseudomonas aeruginosa colonizes the cystic fibrosis (CF) airways causing chronic bacterial lung infections. CF patients are routinely treated with macrolides, however, P. aeruginosa is considered insusceptible as consequence of inadequate susceptibility testing leaving resistance mechanism completely overlooked. Here, we investigated a new mechanism of macrolide resistance caused by ribosomal protein mutations. METHODS Investigating a longitudinal collection of 529 isolates from CF patients and analysing 5758 protein sequences from different sources, mutations in P. aeruginosa's ribosomal proteins connected to macrolide resistance were identified. Using a modified susceptibility testing protocol, isolates harbouring a mutated uL4 ribosomal protein were tested for resistance against macrolide antibiotics and macrolide-induced quorum sensing modulation. Proteome and ribosome profiling were applied to assess the impact of the mutations on the bacterial physiology. RESULTS Five uL4 mutations were identified in isolates from different CF patients. Most mapped to the conserved loop region of uL4 and resulted in increased macrolide tolerance (>10-fold relative to wt strains). Greater concentrations (>10-fold) of macrolide antibiotic were needed to inhibit the growth, reduce swimming motility, and induce redox sensitivity of the uL4 mutants. 16 proteins involved in ribosome adaptation displayed altered expression possibly to compensate for the uL4 mutations, which changed the ribosome stoichiometry without negatively affecting bacterial physiology. CONCLUSIONS Macrolide antibiotics should, therefore, be considered as active antimicrobial agents against P. aeruginosa and resistance development should be contemplated when patients are treated with prolonged courses of macrolides. Importantly, improved macrolide susceptibility testing is necessary for the detection of resistant bacteria.
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Affiliation(s)
- Lise Goltermann
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | | | - Helle Krogh Johansen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Department of Clinical Microbiology 9301, Rigshospitalet, 2100, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Søren Molin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Ruggero La Rosa
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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A Survey of Spontaneous Antibiotic-Resistant Mutants of the Halophilic, Thermophilic Bacterium Rhodothermus marinus. Antibiotics (Basel) 2021; 10:antibiotics10111384. [PMID: 34827322 PMCID: PMC8614978 DOI: 10.3390/antibiotics10111384] [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: 09/19/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022] Open
Abstract
Rhodothermus marinus is a halophilic extreme thermophile, with potential as a model organism for studies of the structural basis of antibiotic resistance. In order to facilitate genetic studies of this organism, we have surveyed the antibiotic sensitivity spectrum of R. marinus and identified spontaneous antibiotic-resistant mutants. R. marinus is naturally insensitive to aminoglycosides, aminocylitols and tuberactinomycins that target the 30S ribosomal subunit, but is sensitive to all 50S ribosomal subunit-targeting antibiotics examined, including macrolides, lincosamides, streptogramin B, chloramphenicol, and thiostrepton. It is also sensitive to kirromycin and fusidic acid, which target protein synthesis factors. It is sensitive to rifampicin (RNA polymerase inhibitor) and to the fluoroquinolones ofloxacin and ciprofloxacin (DNA gyrase inhibitors), but insensitive to nalidixic acid. Drug-resistant mutants were identified using rifampicin, thiostrepton, erythromycin, spiramycin, tylosin, lincomycin, and chloramphenicol. The majority of these were found to have mutations that are similar or identical to those previously found in other species, while several novel mutations were identified. This study provides potential selectable markers for genetic manipulations and demonstrates the feasibility of using R. marinus as a model system for studies of ribosome and RNA polymerase structure, function, and evolution.
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Martinez-Seidel F, Beine-Golovchuk O, Hsieh YC, Eshraky KE, Gorka M, Cheong BE, Jimenez-Posada EV, Walther D, Skirycz A, Roessner U, Kopka J, Pereira Firmino AA. Spatially Enriched Paralog Rearrangements Argue Functionally Diverse Ribosomes Arise during Cold Acclimation in Arabidopsis. Int J Mol Sci 2021; 22:6160. [PMID: 34200446 PMCID: PMC8201131 DOI: 10.3390/ijms22116160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/23/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022] Open
Abstract
Ribosome biogenesis is essential for plants to successfully acclimate to low temperature. Without dedicated steps supervising the 60S large subunits (LSUs) maturation in the cytosol, e.g., Rei-like (REIL) factors, plants fail to accumulate dry weight and fail to grow at suboptimal low temperatures. Around REIL, the final 60S cytosolic maturation steps include proofreading and assembly of functional ribosomal centers such as the polypeptide exit tunnel and the P-Stalk, respectively. In consequence, these ribosomal substructures and their assembly, especially during low temperatures, might be changed and provoke the need for dedicated quality controls. To test this, we blocked ribosome maturation during cold acclimation using two independent reil double mutant genotypes and tested changes in their ribosomal proteomes. Additionally, we normalized our mutant datasets using as a blank the cold responsiveness of a wild-type Arabidopsis genotype. This allowed us to neglect any reil-specific effects that may happen due to the presence or absence of the factor during LSU cytosolic maturation, thus allowing us to test for cold-induced changes that happen in the early nucleolar biogenesis. As a result, we report that cold acclimation triggers a reprogramming in the structural ribosomal proteome. The reprogramming alters the abundance of specific RP families and/or paralogs in non-translational LSU and translational polysome fractions, a phenomenon known as substoichiometry. Next, we tested whether the cold-substoichiometry was spatially confined to specific regions of the complex. In terms of RP proteoforms, we report that remodeling of ribosomes after a cold stimulus is significantly constrained to the polypeptide exit tunnel (PET), i.e., REIL factor binding and functional site. In terms of RP transcripts, cold acclimation induces changes in RP families or paralogs that are significantly constrained to the P-Stalk and the ribosomal head. The three modulated substructures represent possible targets of mechanisms that may constrain translation by controlled ribosome heterogeneity. We propose that non-random ribosome heterogeneity controlled by specialized biogenesis mechanisms may contribute to a preferential or ultimately even rigorous selection of transcripts needed for rapid proteome shifts and successful acclimation.
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Affiliation(s)
- Federico Martinez-Seidel
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
- School of BioSciences, University of Melbourne, Parkville, VIC 3010, Australia;
| | - Olga Beine-Golovchuk
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
- Heidelberg University, Biochemie-Zentrum, Nuclear Pore Complex and Ribosome Assembly, 69120 Heidelberg, Germany
| | - Yin-Chen Hsieh
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
- Institute for Arctic and Marine Biology, UiT Arctic University of Norway, 9037 Tromsø, Norway
| | - Kheloud El Eshraky
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
| | - Michal Gorka
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
| | - Bo-Eng Cheong
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
- School of BioSciences, University of Melbourne, Parkville, VIC 3010, Australia;
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Malaysia
| | - Erika V. Jimenez-Posada
- Grupo de Biotecnología-Productos Naturales, Universidad Tecnológica de Pereira, Pereira 660003, Colombia;
- Emerging Infectious Diseases and Tropical Medicine Research Group—Sci-Help, Pereira 660009, Colombia
| | - Dirk Walther
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
| | - Aleksandra Skirycz
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
| | - Ute Roessner
- School of BioSciences, University of Melbourne, Parkville, VIC 3010, Australia;
| | - Joachim Kopka
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
| | - Alexandre Augusto Pereira Firmino
- Willmitzer Department, Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (O.B.-G.); (Y.-C.H.); (K.E.E.); (M.G.); (B.-E.C.); (D.W.); (A.S.); (J.K.); (A.A.P.F.)
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Lynch CT, Lynch H, Burke S, Hawkins K, Buttimer C, Mc Carthy C, Egan J, Whyte P, Bolton D, Coffey A, Lucey B. Antimicrobial Resistance Determinants Circulating among Thermophilic Campylobacter Isolates Recovered from Broilers in Ireland Over a One-Year Period. Antibiotics (Basel) 2020; 9:E308. [PMID: 32521746 PMCID: PMC7344827 DOI: 10.3390/antibiotics9060308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 02/07/2023] Open
Abstract
Campylobacteriosis is the leading cause of human bacterial gastroenteritis, very often associated with poultry consumption. Thermophilic Campylobacter (Campylobacter jejuni and Campylobacter coli) isolates (n = 158) recovered from broiler neck skin and caecal contents in Ireland over a one-year period, resistant to at least one of three clinically relevant antimicrobial classes, were screened for resistance determinants. All ciprofloxacin-resistant isolates (n = 99) harboured the C257T nucleotide mutation (conferring the Thr-86-Ile substitution) in conjunction with other synonymous and nonsynonymous mutations, which may have epidemiological value. The A2075G nucleotide mutation and amino acid substitutions in L4 and L22 were detected in all erythromycin-resistant isolates (n = 5). The tetO gene was detected in 100% (n = 119) of tetracycline-resistant isolates and three of which were found to harbour the mosaic tetracycline resistance gene tetO/32/O. Two streptomycin-resistant C. jejuni isolates (isolated from the same flock) harboured ant(6)-Ib, located in a multidrug resistance genomic island, containing aminoglycoside, streptothricin (satA) and tetracycline resistance genes (truncated tetO and mosaic tetO/32/O). The ant(6)-Ie gene was identified in two streptomycin-resistant C. coli isolates. This study highlights the widespread acquisition of antimicrobial resistance determinants among chicken-associated Campylobacter isolates, through horizontal gene transfer or clonal expansion of resistant lineages. The stability of such resistance determinants is compounded by the fluidity of mobile genetic element.
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Affiliation(s)
- Caoimhe T. Lynch
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
| | - Helen Lynch
- NRL Campylobacter, Backweston Laboratory Complex, Young’s Cross, Celbridge, W23 X3PH Kildare, Ireland; (H.L.); (J.E.)
- School of Veterinary Medicine, University College Dublin, Belfield, D04 V1W8 Dublin 4, Ireland;
| | - Sarah Burke
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
| | - Kayleigh Hawkins
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
| | - Colin Buttimer
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
| | - Conor Mc Carthy
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
| | - John Egan
- NRL Campylobacter, Backweston Laboratory Complex, Young’s Cross, Celbridge, W23 X3PH Kildare, Ireland; (H.L.); (J.E.)
| | - Paul Whyte
- School of Veterinary Medicine, University College Dublin, Belfield, D04 V1W8 Dublin 4, Ireland;
| | - Declan Bolton
- Teagasc Food Research Centre, Ashtown, D15 DY05 Dublin 15, Ireland;
| | - Aidan Coffey
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
| | - Brigid Lucey
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, T12 P928 Cork, Ireland; (C.T.L.); (S.B.); (K.H.); (C.M.C.); (A.C.)
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Biswas S, Keightley A, Biswas I. Ribosomal protein L4 of Lactobacillus rhamnosus LRB alters resistance to macrolides and other antibiotics. Mol Oral Microbiol 2020; 35:106-119. [PMID: 32022979 DOI: 10.1111/omi.12281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/23/2020] [Accepted: 02/03/2020] [Indexed: 01/09/2023]
Abstract
Lactobacillus rhamnosus is an important lactic acid bacterium that is predominantly used as a probiotic supplement. This bacterium secretes immunomodulatory and antibacterial peptides that are necessary for the probiotic trait. This organism also occupies diverse ecological niches, such as gastrointestinal tracts and the oral cavity. Several studies have shown that L. rhamnosus is prone to spontaneous genome rearrangement irrespective of the ecological origins. We previously characterized an oral isolate of L. rhamnosus, LRB, which is genetically closely related to the widely used probiotic strain L. rhamnosus LGG. In this study, we isolated a nontargeted mutant that was particularly sensitive to acid stress. Using next generation sequencing, we further mapped the putative mutations in the genome and found that the mutant had acquired a deletion of 75 base pairs in the rplD gene that encodes the large ribosomal subunit L4. The mutant had a growth defect at 37°C and at ambient temperature. Further antibiotic sensitivity analyses indicated that the mutant is relatively more resistant to erythromycin and chloramphenicol; two antibiotics that target the 50S subunit. In contrast, the mutant was more sensitive to tetracycline, which targets the 30S subunit. Thus, it appears that nontargeted mutations could significantly alter the antibiotic resistance profile of L. rhamnosus. Our study raises concern that probiotic use of L. rhamnosus should be carefully monitored to avoid unintended consequences.
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Affiliation(s)
- Saswati Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Andrew Keightley
- Mass Spectrometry and Proteomics, UMKC School of Biological Sciences, Kansas City, MO, USA
| | - Indranil Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
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Nikulin AD. Structural Aspects of Ribosomal RNA Recognition by Ribosomal Proteins. BIOCHEMISTRY (MOSCOW) 2018; 83:S111-S133. [DOI: 10.1134/s0006297918140109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Costa-Lourenço APRD, Barros Dos Santos KT, Moreira BM, Fracalanzza SEL, Bonelli RR. Antimicrobial resistance in Neisseria gonorrhoeae: history, molecular mechanisms and epidemiological aspects of an emerging global threat. Braz J Microbiol 2017; 48:617-628. [PMID: 28754299 PMCID: PMC5628311 DOI: 10.1016/j.bjm.2017.06.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 06/03/2017] [Accepted: 06/05/2017] [Indexed: 12/31/2022] Open
Abstract
Neisseria gonorrhoeae is the agent of gonorrhea, a sexually transmitted infection with an estimate from The World Health Organization of 78 million new cases in people aged 15-49 worldwide during 2012. If left untreated, complications may include pelvic inflammatory disease and infertility. Antimicrobial treatment is usually effective; however, resistance has emerged successively through various molecular mechanisms for all the regularly used therapeutic agents throughout decades. Detection of antimicrobial susceptibility is currently the most critical aspect for N. gonorrhoeae surveillance, however poorly structured health systems pose difficulties. In this review, we compiled data from worldwide reports regarding epidemiology and antimicrobial resistance in N. gonorrhoeae, and highlight the relevance of the implementation of surveillance networks to establish policies for gonorrhea treatment.
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Affiliation(s)
| | | | - Beatriz Meurer Moreira
- Institute of Microbiology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | - Raquel Regina Bonelli
- Institute of Microbiology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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10
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Mallik S, Kundu S. Modular Organization of Residue-Level Contacts Shapes the Selection Pressure on Individual Amino Acid Sites of Ribosomal Proteins. Genome Biol Evol 2017; 9:916-931. [PMID: 28338825 PMCID: PMC5388290 DOI: 10.1093/gbe/evx036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2017] [Indexed: 12/26/2022] Open
Abstract
Understanding the molecular evolution of macromolecular complexes in the light of their structure, assembly, and stability is of central importance. Here, we address how the modular organization of native molecular contacts shapes the selection pressure on individual residue sites of ribosomal complexes. The bacterial ribosomal complex is represented as a residue contact network where nodes represent amino acid/nucleotide residues and edges represent their van der Waals interactions. We find statistically overrepresented native amino acid-nucleotide contacts (OaantC, one amino acid contacts one or multiple nucleotides, internucleotide contacts are disregarded). Contact number is defined as the number of nucleotides contacted. Involvement of individual amino acids in OaantCs with smaller contact numbers is more random, whereas only a few amino acids significantly contribute to OaantCs with higher contact numbers. An investigation of structure, stability, and assembly of bacterial ribosome depicts the involvement of these OaantCs in diverse biophysical interactions stabilizing the complex, including high-affinity protein-RNA contacts, interprotein cooperativity, intersubunit bridge, packing of multiple ribosomal RNA domains, etc. Amino acid-nucleotide constituents of OaantCs with higher contact numbers are generally associated with significantly slower substitution rates compared with that of OaantCs with smaller contact numbers. This evolutionary rate heterogeneity emerges from the strong purifying selection pressure that conserves the respective amino acid physicochemical properties relevant to the stabilizing interaction with OaantC nucleotides. An analysis of relative molecular orientations of OaantC residues and their interaction energetics provides the biophysical ground of purifying selection conserving OaantC amino acid physicochemical properties.
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Affiliation(s)
- Saurav Mallik
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
- Center of Excellence in Systems Biology and Biomedical Engineering (TEQIP Phase-II), University of Calcutta, Kolkata, India
| | - Sudip Kundu
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
- Center of Excellence in Systems Biology and Biomedical Engineering (TEQIP Phase-II), University of Calcutta, Kolkata, India
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Fernández-Pevida A, Martín-Villanueva S, Murat G, Lacombe T, Kressler D, de la Cruz J. The eukaryote-specific N-terminal extension of ribosomal protein S31 contributes to the assembly and function of 40S ribosomal subunits. Nucleic Acids Res 2016; 44:7777-91. [PMID: 27422873 PMCID: PMC5027506 DOI: 10.1093/nar/gkw641] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/07/2016] [Indexed: 11/12/2022] Open
Abstract
The archaea-/eukaryote-specific 40S-ribosomal-subunit protein S31 is expressed as an ubiquitin fusion protein in eukaryotes and consists of a conserved body and a eukaryote-specific N-terminal extension. In yeast, S31 is a practically essential protein, which is required for cytoplasmic 20S pre-rRNA maturation. Here, we have studied the role of the N-terminal extension of the yeast S31 protein. We show that deletion of this extension partially impairs cell growth and 40S subunit biogenesis and confers hypersensitivity to aminoglycoside antibiotics. Moreover, the extension harbours a nuclear localization signal that promotes active nuclear import of S31, which associates with pre-ribosomal particles in the nucleus. In the absence of the extension, truncated S31 inefficiently assembles into pre-40S particles and two subpopulations of mature small subunits, one lacking and another one containing truncated S31, can be identified. Plasmid-driven overexpression of truncated S31 partially suppresses the growth and ribosome biogenesis defects but, conversely, slightly enhances the hypersensitivity to aminoglycosides. Altogether, these results indicate that the N-terminal extension facilitates the assembly of S31 into pre-40S particles and contributes to the optimal translational activity of mature 40S subunits but has only a minor role in cytoplasmic cleavage of 20S pre-rRNA at site D.
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Affiliation(s)
- Antonio Fernández-Pevida
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Sara Martín-Villanueva
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Thierry Lacombe
- Department of Microbiology and Molecular Medicine, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
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12
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Lawrence MG, Shamsuzzaman M, Kondopaka M, Pascual C, Zengel JM, Lindahl L. The extended loops of ribosomal proteins uL4 and uL22 of Escherichia coli contribute to ribosome assembly and protein translation. Nucleic Acids Res 2016; 44:5798-810. [PMID: 27257065 PMCID: PMC4937340 DOI: 10.1093/nar/gkw493] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 05/21/2016] [Indexed: 11/13/2022] Open
Abstract
Nearly half of ribosomal proteins are composed of a domain on the ribosome surface and a loop or extension that penetrates into the organelle's RNA core. Our previous work showed that ribosomes lacking the loops of ribosomal proteins uL4 or uL22 are still capable of entering polysomes. However, in those experiments we could not address the formation of mutant ribosomes, because we used strains that also expressed wild-type uL4 and uL22. Here, we have focused on ribosome assembly and function in strains in which loop deletion mutant genes are the only sources of uL4 or uL22 protein. The uL4 and uL22 loop deletions have different effects, but both mutations result in accumulation of immature particles that do not accumulate in detectable amounts in wild-type strains. Thus, our results suggest that deleting the loops creates kinetic barriers in the normal assembly pathway, possibly resulting in assembly via alternate pathway(s). Furthermore, deletion of the uL4 loop results in cold-sensitive ribosome assembly and function. Finally, ribosomes carrying either of the loop-deleted proteins responded normally to the secM translation pausing peptide, but the uL4 mutant responded very inefficiently to the cmlAcrb pause peptide.
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Affiliation(s)
- Marlon G Lawrence
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Md Shamsuzzaman
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Maithri Kondopaka
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Clarence Pascual
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Janice M Zengel
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Lasse Lindahl
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
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13
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Functional Characterization of the Serine-Rich Tract of Varicella-Zoster Virus IE62. J Virol 2015; 90:959-71. [PMID: 26537679 DOI: 10.1128/jvi.02096-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/27/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The immediate early 62 protein (IE62) of varicella-zoster virus (VZV), a major viral trans-activator, initiates the virus life cycle and is a key component of pathogenesis. The IE62 possesses several domains essential for trans-activation, including an acidic trans-activation domain (TAD), a serine-rich tract (SRT), and binding domains for USF, TFIIB, and TATA box binding protein (TBP). Transient-transfection assays showed that the VZV IE62 lacking the SRT trans-activated the early VZV ORF61 promoter at only 16% of the level of the full-length IE62. When the SRT of IE62 was replaced with the SRT of equine herpesvirus 1 (EHV-1) IEP, its trans-activation activity was completely restored. Herpes simplex virus 1 (HSV-1) ICP4 that lacks a TAD very weakly (1.5-fold) trans-activated the ORF61 promoter. An IE62 TAD-ICP4 chimeric protein exhibited trans-activation ability (10.2-fold), indicating that the IE62 TAD functions with the SRT of HSV-1 ICP4 to trans-activate viral promoters. When the serine and acidic residues of the SRT were replaced with Ala, Leu, and Gly, trans-activation activities of the modified IE62 proteins IE62-SRTΔSe and IE62-SRTΔAc were reduced to 46% and 29% of wild-type activity, respectively. Bimolecular complementation assays showed that the TAD of IE62, EHV-1 IEP, and HSV-1 VP16 interacted with Mediator 25 in human melanoma MeWo cells. The SRT of IE62 interacted with the nucleolar-ribosomal protein EAP, which resulted in the formation of globular structures within the nucleus. These results suggest that the SRT plays an important role in VZV viral gene expression and replication. IMPORTANCE The immediate early 62 protein (IE62) of varicella-zoster virus (VZV) is a major viral trans-activator and is essential for viral growth. Our data show that the serine-rich tract (SRT) of VZV IE62, which is well conserved within the alphaherpesviruses, is needed for trans-activation mediated by the acidic trans-activation domain (TAD). The TADs of IE62, EHV-1 IEP, and HSV-1 VP16 interacted with cellular Mediator 25 in bimolecular complementation assays. The interaction of the IE62 SRT with nucleolar-ribosomal protein EAP resulted in the formation of globular structures within the nucleus. Understanding the mechanisms by which the TAD and SRT of IE62 contribute to the function of this essential regulatory protein is important in understanding the gene program of this human pathogen.
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14
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Ou G, Liu Y, Tang Y, You X, Zeng Y, Xiao J, Chen L, Yu M, Wang M, Zhu C. In vitro subminimum inhibitory concentrations of macrolide antibiotics induce macrolide resistance in Mycoplasma pneumoniae. Hippokratia 2015; 19:57-62. [PMID: 26435649 PMCID: PMC4574589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
AIM This study aims to investigate the inducing effect of subminimum inhibitory concentrations of macrolide antibiotics on Mycoplasma pneumoniae (M. pneumoniae) resistance to drugs. MATERIALS AND METHODS One M. pneumoniae reference strain M129 (ATCC 29342) and 104 clinical isolates were incubated at 37C for 6-8 days. Genomic DNA of M. pneumoniae was extracted using TIANamp Bacteria DNA kit and amplified by polymerase chain reaction (PCR). RESULTS Ten sensitive isolates obtained from 104 M. pneumoniae clinical isolates were induced by subminimum inhibitory concentrations of macrolide antibiotics. Among them, three were found to possess mutations in L4 and L22 ribosomal proteins. Two cases carried simultaneously the C162A and A430G mutations of L4 and the T279C mutation of L22. In addition, one case had only the A209T mutation of L4. CONCLUSIONS Repeated in vitro exposure to subminimum inhibitory concentrations of macrolide antibiotics could induce selective mutations in ribosomal genes of M. pneumoniae clinical isolates that cause resistance to macrolide antibiotics. Hippokratia 2015, 19 (1): 57-62.
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Affiliation(s)
- G Ou
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - Y Liu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Y Tang
- Shaoyang Medical College, Shaoyang City, Hunan Province, P.R. China
| | - X You
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - Y Zeng
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - J Xiao
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - L Chen
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - M Yu
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
| | - M Wang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - C Zhu
- Institution of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key, Laboratory for Special Pathogens Prevention and Control, Hengyang City, Hunan Province, P.R. China
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15
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Gamalinda M, Woolford JL. Deletion of L4 domains reveals insights into the importance of ribosomal protein extensions in eukaryotic ribosome assembly. RNA (NEW YORK, N.Y.) 2014; 20:1725-31. [PMID: 25246649 PMCID: PMC4201825 DOI: 10.1261/rna.046649.114] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Numerous ribosomal proteins have a striking bipartite architecture: a globular body positioned on the ribosomal exterior and an internal loop buried deep into the rRNA core. In eukaryotes, a significant number of conserved r-proteins have evolved extra amino- or carboxy-terminal tail sequences, which thread across the solvent-exposed surface. The biological importance of these extended domains remains to be established. In this study, we have investigated the universally conserved internal loop and the eukaryote-specific extensions of yeast L4. We show that in contrast to findings with bacterial L4, deleting the internal loop of yeast L4 causes severely impaired growth and reduced levels of large ribosomal subunits. We further report that while depleting the entire L4 protein blocks early assembly steps in yeast, deletion of only its extended internal loop affects later steps in assembly, revealing a second role for L4 during ribosome biogenesis. Surprisingly, deletion of the entire eukaryote-specific carboxy-terminal tail of L4 has no effect on viability, production of 60S subunits, or translation. These unexpected observations provide impetus to further investigate the functions of ribosomal protein extensions, especially eukaryote-specific examples, in ribosome assembly and function.
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Affiliation(s)
- Michael Gamalinda
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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16
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Mikhaylina AO, Kostareva OS, Sarskikh AV, Fedorov RV, Piendl W, Garber MB, Tishchenko SV. Investigation of the regulatory function of archaeal ribosomal protein L4. BIOCHEMISTRY (MOSCOW) 2014; 79:69-76. [PMID: 24512666 DOI: 10.1134/s0006297914010106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ribosomal protein L4 is a regulator of protein synthesis in the Escherichia coli S10 operon, which contains genes of 11 ribosomal proteins. In this work, we have investigated regulatory functions of ribosomal protein L4 of the thermophilic archaea Methanococcus jannaschii. The S10-like operon from M. jannaschii encodes not 11, but only five ribosomal proteins (L3, L4, L23, L2, S19), and the first protein is L3 instead of S10. We have shown that MjaL4 and its mutant form lacking an elongated loop specifically inhibit expression of the first gene of the S10-like operon from the same organism in a coupled transcription-translation system in vitro. By deletion analysis, an L4-binding regulatory site has been found on MjaL3 mRNA, and a fragment of mRNA with length of 40 nucleotides has been prepared that is necessary and sufficient for the specific interaction with the MjaL4 protein.
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Affiliation(s)
- A O Mikhaylina
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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17
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Calidas D, Lyon H, Culver GM. The N-terminal extension of S12 influences small ribosomal subunit assembly in Escherichia coli. RNA (NEW YORK, N.Y.) 2014; 20:321-30. [PMID: 24442609 PMCID: PMC3923127 DOI: 10.1261/rna.042432.113] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The small subunit (SSU) of the ribosome of E. coli consists of a core of ribosomal RNA (rRNA) surrounded peripherally by ribosomal proteins (r-proteins). Ten of the 15 universally conserved SSU r-proteins possess nonglobular regions called extensions. The N-terminal noncanonically structured extension of S12 traverses from the solvent to intersubunit surface of the SSU and is followed by a more C-terminal globular region that is adjacent to the decoding center of the SSU. The role of the globular region in maintaining translational fidelity is well characterized, but a role for the S12 extension in SSU structure and function is unknown. We examined the effect of stepwise truncation of the extension of S12 in SSU assembly and function in vitro and in vivo. Examination of in vitro assembly in the presence of sequential N-terminal truncated variants of S12 reveals that N-terminal deletions of greater than nine amino acids exhibit decreased tRNA-binding activity and altered 16S rRNA architecture particularly in the platform of the SSU. While wild-type S12 expressed from a plasmid can rescue a genomic deletion of the essential gene for S12, rpsl; N-terminal deletions of S12 exhibit deleterious phenotypic consequences. Partial N-terminal deletions of S12 are slow growing and cold sensitive. Strains bearing these truncations as the sole copy of S12 have increased levels of free SSUs and immature 16S rRNA as compared with the wild-type S12. These differences are hallmarks of SSU biogenesis defects, indicating that the extension of S12 plays an important role in SSU assembly.
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Affiliation(s)
- Deepika Calidas
- Department of Biology, Center for RNA Biology: From Genome to Therapeutics, University of Rochester Medical Center, Rochester, New York 14627, USA
| | - Hiram Lyon
- Department of Biology, Center for RNA Biology: From Genome to Therapeutics, University of Rochester Medical Center, Rochester, New York 14627, USA
| | - Gloria M. Culver
- Department of Biology, Center for RNA Biology: From Genome to Therapeutics, University of Rochester Medical Center, Rochester, New York 14627, USA
- Corresponding authorE-mail
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18
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Chen J, Yu Y, Wang J, Gu Y, Sun X, Xu J, Zeng Z. Three cases of acute gastroenteritis caused by high-level macrolideresistant Campylobacter: drug resistance mechanisms and clinical characteristics. SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 2012; 44:541-543. [PMID: 22385190 DOI: 10.3109/00365548.2012.656319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We report 3 cases of acute gastroenteritis caused by high-level macrolide-resistant Campylobacter. The clinical characteristics of patients were studied, and the rplD, rplV, and 23S rRNA domain V genes were sequenced to detected resistance-related mutations.
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Affiliation(s)
- Jie Chen
- Department of Infectious Diseases, Peking University First Hospital, Beijing, China
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19
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Chen J, Yu Y, Wang J, Gu Y, Sun X, Xu J, Zeng Z. Three cases of acute gastroenteritis caused by high-level macrolideresistant Campylobacter: Drug resistance mechanisms and clinical characteristics. SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 2012; 44:541-543. [DOI: https:/doi.org/10.3109/00365548.2012.656319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Abstract
Expression of retroviral replication enzymes (Pol) requires a controlled translational recoding event to bypass the stop codon at the end of gag. This recoding event occurs either by direct suppression of termination via the insertion of an amino acid at the stop codon (readthrough) or by alteration of the mRNA reading frame (frameshift). Here we report the effects of a host protein, large ribosomal protein 4 (RPL4), on the efficiency of recoding. Using a dual luciferase reporter assay, we found that transfection of cells with a plasmid encoding RPL4 cDNA increases recoding efficiency in a dose-dependent manner, with a maximal enhancement of nearly twofold. Expression of RPL4 increases recoding of reporters containing retroviral readthrough and frameshift sequences, as well as the Sindbis virus leaky termination signal. RPL4-induced enhancement of recoding is cell line specific and appears to be specific to RPL4 among ribosomal proteins. Cotransfection of RPL4 cDNA with Moloney murine leukemia proviral DNA results in Gag processing defects and a reduction of viral particle formation, presumably caused by the RPL4-dependent alteration of the Gag-to-Gag-Pol ratio required for virion assembly and release.
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21
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Pérez-Boto D, López-Portolés JA, Simón C, Valdezate S, Echeita MA. Study of the molecular mechanisms involved in high-level macrolide resistance of Spanish Campylobacter jejuni and Campylobacter coli strains. J Antimicrob Chemother 2010; 65:2083-8. [PMID: 20647243 DOI: 10.1093/jac/dkq268] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To investigate the molecular mechanisms involved in the high-level erythromycin resistance of clinical Spanish Campylobacter jejuni and Campylobacter coli strains. METHODS Overall susceptibilities of 678 C. jejuni and 119 C. coli strains, collected from 10 Spanish provinces during 2006 and 2007, were determined by Etest. In high-level erythromycin-resistant strains, molecular determinants were studied. The analysis was focused on region V of the 23S rRNA gene, the rplD and rplV ribosomal genes, and the regulatory region of the CmeABC efflux pump. RESULTS The global resistance rate to erythromycin was 3.8%. Among the resistant strains, 93% were C. coli and 7% were C. jejuni. The A2075G mutation in the 23S rRNA gene was detected in all of the resistant strains except for two, which carried the A2074G mutation. None of the ribosomal rplD and rplV genes harboured the described mutations that confer resistance to macrolides. Different mutations affecting the regulatory region of the CmeABC efflux pump were also found. CONCLUSIONS C. coli strains are clearly more resistant to erythromycin than C. jejuni. The mutation A2075G in the 23S rRNA gene was responsible for the resistance in most of the strains; A2074G was only found in two strains. Further studies are required to ascertain the effect of mutations in the regulatory region of cmeABC. Our data indicate that the rate of resistance was similar to that of other European countries.
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Affiliation(s)
- D Pérez-Boto
- Laboratorio de Campylobacter, Servicio de Bacteriología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain.
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22
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Pöll G, Braun T, Jakovljevic J, Neueder A, Jakob S, Woolford JL, Tschochner H, Milkereit P. rRNA maturation in yeast cells depleted of large ribosomal subunit proteins. PLoS One 2009; 4:e8249. [PMID: 20011513 PMCID: PMC2788216 DOI: 10.1371/journal.pone.0008249] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 11/13/2009] [Indexed: 11/19/2022] Open
Abstract
The structural constituents of the large eukaryotic ribosomal subunit are 3 ribosomal RNAs, namely the 25S, 5.8S and 5S rRNA and about 46 ribosomal proteins (r-proteins). They assemble and mature in a highly dynamic process that involves more than 150 proteins and 70 small RNAs. Ribosome biogenesis starts in the nucleolus, continues in the nucleoplasm and is completed after nucleo-cytoplasmic translocation of the subunits in the cytoplasm. In this work we created 26 yeast strains, each of which conditionally expresses one of the large ribosomal subunit (LSU) proteins. In vivo depletion of the analysed LSU r-proteins was lethal and led to destabilisation and degradation of the LSU and/or its precursors. Detailed steady state and metabolic pulse labelling analyses of rRNA precursors in these mutant strains showed that LSU r-proteins can be grouped according to their requirement for efficient progression of different steps of large ribosomal subunit maturation. Comparative analyses of the observed phenotypes and the nature of r-protein-rRNA interactions as predicted by current atomic LSU structure models led us to discuss working hypotheses on i) how individual r-proteins control the productive processing of the major 5' end of 5.8S rRNA precursors by exonucleases Rat1p and Xrn1p, and ii) the nature of structural characteristics of nascent LSUs that are required for cytoplasmic accumulation of nascent subunits but are nonessential for most of the nuclear LSU pre-rRNA processing events.
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Affiliation(s)
- Gisela Pöll
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Tobias Braun
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Jelena Jakovljevic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Andreas Neueder
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - Steffen Jakob
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
| | - John L. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (JLW); (HT); (PM)
| | - Herbert Tschochner
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
- * E-mail: (JLW); (HT); (PM)
| | - Philipp Milkereit
- Institut für Biochemie III, Universität Regensburg, Regensburg, Germany
- * E-mail: (JLW); (HT); (PM)
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Soung GY, Miller JL, Koc H, Koc EC. Comprehensive analysis of phosphorylated proteins of Escherichia coli ribosomes. J Proteome Res 2009; 8:3390-402. [PMID: 19469554 PMCID: PMC2760691 DOI: 10.1021/pr900042e] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Phosphorylation of bacterial ribosomal proteins has been known for decades; however, there is still very limited information available on specific locations of the phosphorylation sites in ribosomal proteins and the role they might play in protein synthesis. In this study, we have mapped the specific phosphorylation sites in 24 Escherichia coli ribosomal proteins by tandem mass spectrometry. Detection of phosphorylation was achieved by either phosphorylation specific visualization techniques, ProQ staining, and antibodies for phospho-Ser, Thr, and Tyr; or by mass spectrometry equipped with a capability to detect addition and loss of the phosphate moiety. Enrichment by immobilized metal affinity and/or strong cation exchange chromatography was used to improve the success of detection of the low abundance phosphopeptides. We found the small subunit (30S) proteins S3, S4, S5, S7, S11, S12, S13, S18, and S21 and the large subunit (50S) proteins L1, L2, L3, L5, L6, L7/L12, L13, L14, L16, L18, L19, L21, L22, L28, and L31 to be phosphorylated at one or more residues. Potential roles for each specific site in ribosome function were deduced through careful evaluation of the given phosphorylation sites in 3D-crystal structure models of ribosomes and the previous mutational studies of E. coli ribosomal proteins.
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Affiliation(s)
- George Y Soung
- Department of Biochemistry & Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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24
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Timsit Y, Acosta Z, Allemand F, Chiaruttini C, Springer M. The role of disordered ribosomal protein extensions in the early steps of eubacterial 50 S ribosomal subunit assembly. Int J Mol Sci 2009; 10:817-834. [PMID: 19399222 PMCID: PMC2672003 DOI: 10.3390/ijms10030817] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 02/23/2009] [Accepted: 02/24/2009] [Indexed: 12/23/2022] Open
Abstract
Although during the past decade research has shown the functional importance of disorder in proteins, many of the structural and dynamics properties of intrinsically unstructured proteins (IUPs) remain to be elucidated. This review is focused on the role of the extensions of the ribosomal proteins in the early steps of the assembly of the eubacterial 50 S subunit. The recent crystallographic structures of the ribosomal particles have revealed the picture of a complex assembly pathway that condenses the rRNA and the ribosomal proteins into active ribosomes. However, little is know about the molecular mechanisms of this process. It is thought that the long basic r-protein extensions that penetrate deeply into the subunit cores play a key role through disorder-order transitions and/or co-folding mechanisms. A current view is that such structural transitions may facilitate the proper rRNA folding. In this paper, the structures of the proteins L3, L4, L13, L20, L22 and L24 that have been experimentally found to be essential for the first steps of ribosome assembly have been compared. On the basis of their structural and dynamics properties, three categories of extensions have been identified. Each of them seems to play a distinct function. Among them, only the coil-helix transition that occurs in a phylogenetically conserved cluster of basic residues of the L20 extension appears to be strictly required for the large subunit assembly in eubacteria. The role of alpha helix-coil transitions in 23 S RNA folding is discussed in the light of the calcium binding protein calmodulin that shares many structural and dynamics properties with L20.
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Affiliation(s)
- Youri Timsit
- Laboratoire de Cristallographie, Institut de Biologie Physico-Chimique CNRS, 13, rue Pierre et Marie Curie, 75005 Paris, France; E-Mail:
- Author to whom correspondence should be addressed; E-mail:
; Tel. +01-58-41-51-66
| | - Zahir Acosta
- Laboratoire de Cristallographie, Institut de Biologie Physico-Chimique CNRS, 13, rue Pierre et Marie Curie, 75005 Paris, France; E-Mail:
| | - Frédéric Allemand
- Laboratoire de Biochimie, Institut de Biologie Physico-Chimique CNRS, 13, rue Pierre et Marie Curie, 75005 Paris, France; E-Mail:
(F.A.);
(C.C.);
(M.S.)
| | - Claude Chiaruttini
- Laboratoire de Biochimie, Institut de Biologie Physico-Chimique CNRS, 13, rue Pierre et Marie Curie, 75005 Paris, France; E-Mail:
(F.A.);
(C.C.);
(M.S.)
| | - Mathias Springer
- Laboratoire de Biochimie, Institut de Biologie Physico-Chimique CNRS, 13, rue Pierre et Marie Curie, 75005 Paris, France; E-Mail:
(F.A.);
(C.C.);
(M.S.)
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25
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Diner EJ, Hayes CS. Recombineering reveals a diverse collection of ribosomal proteins L4 and L22 that confer resistance to macrolide antibiotics. J Mol Biol 2009; 386:300-15. [PMID: 19150357 PMCID: PMC2644216 DOI: 10.1016/j.jmb.2008.12.064] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 12/18/2008] [Accepted: 12/20/2008] [Indexed: 11/19/2022]
Abstract
Mutations in ribosomal proteins L4 and L22 confer resistance to erythromycin and other macrolide antibiotics in a variety of bacteria. L4 and L22 have elongated loops whose tips converge in the peptide exit tunnel near the macrolide-binding site, and resistance mutations typically affect residues within these loops. Here, we used bacteriophage lambda Red-mediated recombination, or "recombineering," to uncover new L4 and L22 alleles that confer macrolide resistance in Escherichia coli. We randomized residues at the tips of the L4 and L22 loops using recombineered oligonucleotide libraries and selected the mutagenized cells for erythromycin-resistant mutants. These experiments led to the identification of 341 resistance mutations encoding 278 unique L4 and L22 proteins-the overwhelming majority of which are novel. Many resistance mutations were complex, involving multiple missense mutations, in-frame deletions, and insertions. Transfer of L4 and L22 mutations into wild-type cells by phage P1-mediated transduction demonstrated that each allele was sufficient to confer macrolide resistance. Although L4 and L22 mutants are typically resistant to most macrolides, selections carried out on different antibiotics revealed macrolide-specific resistance mutations. L22 Lys90Trp is one such allele that confers resistance to erythromycin but not to tylosin and spiramycin. Purified L22 Lys90Trp ribosomes show reduced erythromycin binding but have the same affinity for tylosin as wild-type ribosomes. Moreover, dimethyl sulfate methylation protection assays demonstrated that L22 Lys90Trp ribosomes bind tylosin more readily than erythromycin in vivo. This work underscores the exceptional functional plasticity of the L4 and L22 proteins and highlights the utility of Red-mediated recombination in targeted genetic selections.
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Affiliation(s)
- Elie J. Diner
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106-9610
| | - Christopher S. Hayes
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106-9610
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106-9610
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26
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Simoff I, Moradi H, Nygård O. Functional characterization of ribosomal protein L15 from Saccharomyces cerevisiae. Curr Genet 2009; 55:111-25. [PMID: 19184027 DOI: 10.1007/s00294-009-0228-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/08/2009] [Accepted: 01/08/2009] [Indexed: 12/20/2022]
Abstract
In this study we provide general information on the little studied eukaryotic ribosomal protein rpL15. Saccharomyces cerevisiae has two genes, YRPL15A and YRPL15B that could potentially code for yeast rpL15 (YrpL15). YRPL15A is essential while YRPL15B is dispensable. However, a plasmid-borne copy of the YRPL15B gene, controlled by the GAL1 promoter or by the promoter controlling expression of the YRPL15A gene, can functionally complement YrpL15A in yeast cells, while the same gene controlled by the authentic promoter is inactive. Analysis of the levels of YrpL15B-mRNA in yeast cells shows that the YRPL15B gene is inactive in transcription. The function of YrpL15A is highly resilient to single and multiple amino acid substitutions. In addition, minor deletions from both the N- and C-terminal ends of YrpL15A has no effect on protein function, while addition of a C-terminal tag that could be used for detection of plasmid-encoded YrpL15A is detrimental to protein function. YrpL15A could also be replaced by the homologous protein from Arabidopsis thaliana despite almost 30% differences in the amino acid sequence, while the more closely related protein from Schizosaccharomyces pombe was inactive. The lack of function was not caused by a failure of the protein to enter the yeast nucleus.
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27
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Luo X, Hsiao HH, Bubunenko M, Weber G, Court DL, Gottesman ME, Urlaub H, Wahl MC. Structural and functional analysis of the E. coli NusB-S10 transcription antitermination complex. Mol Cell 2008; 32:791-802. [PMID: 19111659 PMCID: PMC2627990 DOI: 10.1016/j.molcel.2008.10.028] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 09/24/2008] [Accepted: 10/21/2008] [Indexed: 11/18/2022]
Abstract
Protein S10 is a component of the 30S ribosomal subunit and participates together with NusB protein in processive transcription antitermination. The molecular mechanisms by which S10 can act as a translation or a transcription factor are not understood. We used complementation assays and recombineering to delineate regions of S10 dispensable for antitermination, and determined the crystal structure of a transcriptionally active NusB-S10 complex. In this complex, S10 adopts the same fold as in the 30S subunit and is blocked from simultaneous association with the ribosome. Mass spectrometric mapping of UV-induced crosslinks revealed that the NusB-S10 complex presents an intermolecular, composite, and contiguous binding surface for RNAs containing BoxA antitermination signals. Furthermore, S10 overproduction complemented a nusB null phenotype. These data demonstrate that S10 and NusB together form a BoxA-binding module, that NusB facilitates entry of S10 into the transcription machinery, and that S10 represents a central hub in processive antitermination.
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Affiliation(s)
- Xiao Luo
- Max-Planck-Institute for Biophysical Chemistry, Research Group X-Ray Crystallography
| | - He-Hsuan Hsiao
- Research Group Bioanalytical Mass Spectrometry, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Mikhail Bubunenko
- Gene Regulation and Chromosomal Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Maryland 21702, USA
- Basic Research Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Gert Weber
- Max-Planck-Institute for Biophysical Chemistry, Research Group X-Ray Crystallography
| | - Donald L. Court
- Gene Regulation and Chromosomal Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Maryland 21702, USA
| | - Max E. Gottesman
- Columbia University Medical Center, Departments of Microbiology and Biochemistry and Molecular Biophysics, New York, New York 10032, USA
| | - Henning Urlaub
- Research Group Bioanalytical Mass Spectrometry, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Markus C. Wahl
- Max-Planck-Institute for Biophysical Chemistry, Research Group X-Ray Crystallography
- Georg-August-University Göttingen, Department of Medicine, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
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28
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Revisiting the mechanism of macrolide-antibiotic resistance mediated by ribosomal protein L22. Proc Natl Acad Sci U S A 2008; 105:18261-6. [PMID: 19015512 DOI: 10.1073/pnas.0810357105] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial antibiotic resistance can occur by many mechanisms. An intriguing class of mutants is resistant to macrolide antibiotics even though these drugs still bind to their targets. For example, a 3-residue deletion (DeltaMKR) in ribosomal protein L22 distorts a loop that forms a constriction in the ribosome exit tunnel, apparently allowing nascent-chain egress and translation in the presence of bound macrolides. Here, however, we demonstrate that DeltaMKR and wild-type ribosomes show comparable macrolide sensitivity in vitro. In Escherichia coli, we find that this mutation reduces antibiotic occupancy of the target site on ribosomes in a manner largely dependent on the AcrAB-TolC efflux system. We propose a model for antibiotic resistance in which DeltaMKR ribosomes alter the translation of specific proteins, possibly via changes in programmed stalling, and modify the cell envelope in a manner that lowers steady-state macrolide levels.
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29
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Moore SD, Baker TA, Sauer RT. Forced extraction of targeted components from complex macromolecular assemblies. Proc Natl Acad Sci U S A 2008; 105:11685-90. [PMID: 18695246 PMCID: PMC2575258 DOI: 10.1073/pnas.0805633105] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Indexed: 11/18/2022] Open
Abstract
When individual protein components of supramolecular complexes are required for assembly, determining whether they play additional structural or functional roles can be difficult. Removing a protein from the complex after assembly can circumvent this problem. Here, we show that an AAA+ unfoldase/protease can extract an essential assembly protein from the ribosome. Specifically, Mg(2+) depletion allowed ClpXP to remove an ssrA-tagged variant of ribosomal protein L22 from the 50S subunit of E. coli ribosomes without disrupting either the structural integrity or hydrodynamic properties of the modified particle. Forced extraction using AAA+ enzymes and targeted component proteins should be broadly applicable to the study of macromolecular complexes.
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Affiliation(s)
| | - Tania A. Baker
- *Department of Biology and
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139
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30
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Effects on translation pausing of alterations in protein and RNA components of the ribosome exit tunnel. J Bacteriol 2008; 190:5862-9. [PMID: 18586934 DOI: 10.1128/jb.00632-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amino acids are polymerized into peptides in the peptidyl transferase center of the ribosome. The nascent peptides then pass through the exit tunnel before they reach the extraribosomal environment. A number of nascent peptides interact with the exit tunnel and stall elongation at specific sites within their peptide chain. Several mutational changes in RNA and protein components of the ribosome have previously been shown to interfere with pausing. These changes are localized in the narrowest region of the tunnel, near a constriction formed by ribosomal proteins L4 and L22. To expand our knowledge about peptide-induced pausing, we performed a comparative study of pausing induced by two peptides, SecM and a short peptide, Crb(CmlA), that requires chloramphenicol as a coinducer of pausing. We analyzed the effects of 15 mutational changes in L4 and L22, as well as the effects of methylating nucleotide A2058 of 23S rRNA, a nucleotide previously implicated in pausing and located close to the L4-L22 constriction. Our results show that methylation of A2058 and most mutational changes in L4 and L22 have differential effects on pausing in response to Crb(CmlA) and SecM. Only one change, a 6-amino-acid insertion after amino acid 72 in L4, affects pausing in both peptides. We conclude that the two peptides interact with different regions of the exit tunnel. Our results suggest that either the two peptides use different mechanisms of pausing or they interact differently but induce similar inhibitory conformational changes in functionally important regions of the ribosome.
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31
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Zaman S, Fitzpatrick M, Lindahl L, Zengel J. Novel mutations in ribosomal proteins L4 and L22 that confer erythromycin resistance in Escherichia coli. Mol Microbiol 2007; 66:1039-50. [PMID: 17956547 PMCID: PMC2229831 DOI: 10.1111/j.1365-2958.2007.05975.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
L4 and L22, proteins of the large ribosomal subunit, contain globular surface domains and elongated ‘tentacles’ that reach into the core of the large subunit to form part of the lining of the peptide exit tunnel. Mutations in the tentacles of L4 and L22 confer macrolide resistance in a variety of pathogenic and non-pathogenic bacteria. In Escherichia coli, a Lys-to-Glu mutation in L4 and a three-amino-acid deletion in the L22 had been reported. To learn more about the roles of the tentacles in ribosome assembly and function, we isolated additional erythromycin-resistant E. coli mutants. Eight new mutations mapped in L4, all within the tentacle. Two new mutations were identified in L22; one mapped outside the tentacle. Insertion mutations were found in both genes. All of the mutants grew slower than the parent, and they all showed reduced in vivo rates of peptide-chain elongation and increased levels of precursor 23S rRNA. Large insertions in L4 and L22 resulted in very slow growth and accumulation of abnormal ribosomal subunits. Our results highlight the important role of L4 and L22 in ribosome function and assembly, and indicate that a variety of changes in these proteins can mediate macrolide resistance.
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Affiliation(s)
- Sephorah Zaman
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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32
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Taliaferro DL, Farabaugh PJ. Testing constraints on rRNA bases that make nonsequence-specific contacts with the codon-anticodon complex in the ribosomal A site. RNA (NEW YORK, N.Y.) 2007; 13:1279-86. [PMID: 17592040 PMCID: PMC1924888 DOI: 10.1261/rna.552007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
During protein synthesis, interactions between the decoding center of the ribosome and the codon-anticodon complexes maintain translation accuracy. Correct aminoacyl-tRNAs induce the ribosome to shift into a "closed" conformation that both blocks tRNA dissociation and accelerates the process of tRNA acceptance. As part of the ribosomal recognition of cognate tRNAs, the rRNA nucleotides G530 and A1492 form a hydrogen-bonded pair that interacts with the middle position of the codon.anticodon complex and recognizes correct Watson-Crick base pairs. Exchanging these two nucleotides (A530 and G1492) would not disrupt these interactions, suggesting that such a double mutant ribosome might properly recognize tRNAs and support viability. We find, however, that exchange mutants retain little ribosomal activity. We suggest that even though the exchanged nucleotides might function properly during tRNA recruitment, they might disrupt one or more other functions of the nucleotides during other stages of protein synthesis.
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Affiliation(s)
- Dwayne L Taliaferro
- Program in Molecular and Cell Biology, Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
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33
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Papadopoulos G, Grudinin S, Kalpaxis DL, Choli-Papadopoulou T. Changes in the level of poly(Phe) synthesis in Escherichia coli ribosomes containing mutants of L4 ribosomal protein from Thermus thermophilus can be explained by structural changes in the peptidyltransferase center: a molecular dynamics simulation analysis. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2006; 35:675-83. [PMID: 16773394 DOI: 10.1007/s00249-006-0076-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 05/13/2006] [Accepted: 05/19/2006] [Indexed: 10/24/2022]
Abstract
Data from polyphenylalanine [poly(Phe)] synthesis determination in the presence and in the absence of erythromycin have been used in conjunction with Molecular Dynamics Simulation analysis, in order to localize the functional sites affected by mutations of Thermus thermophilus ribosomal protein L4 incorporated in Escherichia coli ribosomes. We observed that alterations in ribosome capability to synthesize poly(Phe) in the absence of erythromycin were mainly correlated to shifts of A2062 and C2612 of 23S rRNA, while in the presence of erythromycin they were correlated to shifts of A2060 and U2584 of 23S rRNA. Our results suggest a means of understanding the role of the extended loop of L4 ribosomal protein in ribosomal peptidyltransferase center.
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Affiliation(s)
- G Papadopoulos
- Department of Biochemistry and Biotechnology, University of Thessaly, Ploutonos 26, 41221, Larissa, Greece.
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34
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Voss NR, Gerstein M, Steitz TA, Moore PB. The geometry of the ribosomal polypeptide exit tunnel. J Mol Biol 2006; 360:893-906. [PMID: 16784753 DOI: 10.1016/j.jmb.2006.05.023] [Citation(s) in RCA: 238] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Revised: 05/02/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
The geometry of the polypeptide exit tunnel has been determined using the crystal structure of the large ribosomal subunit from Haloarcula marismortui. The tunnel is a component of a much larger, interconnected system of channels accessible to solvent that permeates the subunit and is connected to the exterior at many points. Since water and other small molecules can diffuse into and out of the tunnel along many different trajectories, the large subunit cannot be part of the seal that keeps ions from passing through the ribosome-translocon complex. The structure referred to as the tunnel is the only passage in the solvent channel system that is both large enough to accommodate nascent peptides, and that traverses the particle. For objects of that size, it is effectively an unbranched tube connecting the peptidyl transferase center of the large subunit and the site where nascent peptides emerge. At no point is the tunnel big enough to accommodate folded polypeptides larger than alpha-helices.
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Affiliation(s)
- N R Voss
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
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35
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Maeder C, Draper DE. A Small Protein Unique to Bacteria Organizes rRNA Tertiary Structure Over an Extensive Region of the 50S Ribosomal Subunit. J Mol Biol 2005; 354:436-46. [PMID: 16246363 DOI: 10.1016/j.jmb.2005.09.072] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 09/22/2005] [Accepted: 09/22/2005] [Indexed: 11/17/2022]
Abstract
A number of small, basic proteins penetrate into the structure of the large subunit of the ribosome. While these proteins presumably aid in the folding of the rRNA, the extent of their contribution to the stability or function of the ribosome is unknown. One of these small, basic proteins is L36, which is highly conserved in Bacteria, but is not present in Archaea or Eucarya. Comparison of ribosome crystal structures shows that the space occupied by L36 in a bacterial ribosome is empty in an archaeal ribosome. To ask what L36 contributes to ribosome stability and function, we have constructed an Escherichia coli strain lacking ribosomal protein L36; cell growth is slowed by 40-50% between 30 degrees C and 42 degrees C. Ribosomes from this deletion strain sediment normally and have a full complement of proteins, other than L36. Chemical protection experiments comparing rRNA from wild-type and L36-deficient ribosomes show the expected increase in reagent accessibility in the immediate vicinity of the L36 binding site, but suggest that a cooperative network of rRNA tertiary interactions has been disrupted along a path extending 60 A deep into the ribosome. These data argue that L36 plays a significant role in organizing 23 S rRNA structure. Perhaps the Archaea and Eucarya have compensated for their lack of L36 by maintaining more stable rRNA tertiary contacts or by adopting alternative protein-RNA interactions elsewhere in the ribosome.
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Affiliation(s)
- Corina Maeder
- Program in Molecular and Computational Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
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36
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Tsagkalia A, Leontiadou F, Xaplanteri MA, Papadopoulos G, Kalpaxis DL, Choli-Papadopoulou T. Ribosomes containing mutants of L4 ribosomal protein from Thermus thermophilus display multiple defects in ribosomal functions and sensitivity against erythromycin. RNA (NEW YORK, N.Y.) 2005; 11:1633-9. [PMID: 16244130 PMCID: PMC1370849 DOI: 10.1261/rna.2126205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Protein L4 from Thermus thermophilus (TthL4) was heterologously overproduced in Escherichia coli cells. To study the implication of the extended loop of TthL4 in the exit-tunnel and peptidyltransferase functions, the highly conserved E56 was replaced by D or Q, while the semiconserved G55 was changed to E or S. Moreover, the sequence -G55E56- was inverted to -E55G56-. When we incorporated these mutants into E. coli ribosomes and investigated their impact on poly(Phe) synthesis, high variations in the synthetic activity and response to erythromycin of the resulting ribosomes were observed. In the absence of erythromycin, ribosomes harboring mutations G55E and E56D in TthL4 protein were characterized by low activity in synthesizing poly(Phe) and decreased capability in binding tRNA at the A site. On the other hand, ribosomes possessing mutations G55E, G55S, G55E-E56G, or E56Q in TthL4 protein were unexpectedly more sensitive to erythromycin. Evidence in support of these findings was drawn by in vivo experiments, assessing the erythromycin sensitivity of E. coli cells expressing wild-type or mutant TthL4 proteins. Our results emphasize the role of the extended loop of L4 ribosomal protein in the exit-tunnel and peptidyltransferase center functions.
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Affiliation(s)
- Aikaterini Tsagkalia
- Laboratory of Biochemistry, School of Chemistry, Aristotle University of Thessaloniki, Greece
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37
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Guillier M, Allemand F, Graffe M, Raibaud S, Dardel F, Springer M, Chiaruttini C. The N-terminal extension of Escherichia coli ribosomal protein L20 is important for ribosome assembly, but dispensable for translational feedback control. RNA (NEW YORK, N.Y.) 2005; 11:728-738. [PMID: 15840820 PMCID: PMC1370758 DOI: 10.1261/rna.7134305] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Accepted: 02/03/2005] [Indexed: 05/24/2023]
Abstract
The Escherichia coli autoregulatory ribosomal protein L20 consists of two structurally distinct domains. The C-terminal domain is globular and sits on the surface of the large ribosomal subunit whereas the N-terminal domain has an extended shape and penetrates deep into the RNA-rich core of the subunit. Many other ribosomal proteins have analogous internal or terminal extensions. However, the biological functions of these extended domains remain obscure. Here we show that the N-terminal tail of L20 is important for ribosome assembly in vivo. Indeed, a truncated version of L20 without its N-terminal tail is unable to complement the deletion of rplT, the gene encoding L20. In addition, this L20 truncation confers a lethal-dominant phenotype, suggesting that the N-terminal domain is essential for cell growth because it could be required for ribosome assembly. Supporting this hypothesis, partial deletions of the N-terminal tail of the protein are shown to cause a slow-growth phenotype due to altered ribosome assembly in vivo as large amounts of intermediate 40S ribosomal particles accumulate. In addition to being a ribosomal protein, L20 also acts as an autogenous repressor. Using L20 truncations, we also show that the N-terminal tail of L20 is dispensable for autogenous control.
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Affiliation(s)
- Maude Guillier
- Institut de Biologie Physico-Chimique, UPR 9073 du CNRS, Unité de Régulation de l'Expression Génétique chez les Microorganismes, Paris, France
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38
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Vishwanath P, Favaretto P, Hartman H, Mohr SC, Smith TF. Ribosomal protein-sequence block structure suggests complex prokaryotic evolution with implications for the origin of eukaryotes. Mol Phylogenet Evol 2005; 33:615-25. [PMID: 15522791 DOI: 10.1016/j.ympev.2004.07.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Revised: 06/29/2004] [Indexed: 11/18/2022]
Abstract
Amino acid sequence alignments of orthologous ribosomal proteins found in Bacteria, Archaea, and Eukaryota display, relative to one another, an unusual segment or block structure, with major evolutionary implications. Within each of the prokaryotic phylodomains the sequences exhibit substantial similarity, but cross-domain alignments break up into (a) universal blocks (conserved in both phylodomains), (b) bacterial blocks (unalignable with any archaeal counterparts), and (c) archaeal blocks (unalignable with any bacterial counterparts). Sequences of those eukaryotic cytoplasmic riboproteins that have orthologs in both Bacteria and Archaea, exclusively match the archaeal block structure. The distinct blocks do not correlate consistently with any identifiable functional or structural feature including RNA and protein contacts. This phylodomain-specific block pattern also exists in a number of other proteins associated with protein synthesis, but not among enzymes of intermediary metabolism. While the universal blocks imply that modern Bacteria and Archaea (as defined by their translational machinery) clearly have had a common ancestor, the phylodomain-specific blocks imply that these two groups derive from single, phylodomain-specific types that came into existence at some point long after that common ancestor. The simplest explanation for this pattern would be a major evolutionary bottleneck, or other scenario that drastically limited the progenitors of modern prokaryotic diversity at a time considerably after the evolution of a fully functional translation apparatus. The vast range of habitats and metabolisms that prokaryotes occupy today would thus reflect divergent evolution after such a restricting event. Interestingly, phylogenetic analysis places the origin of eukaryotes at about the same time and shows a closer relationship of the eukaryotic ribosome-associated proteins to crenarchaeal rather than euryarchaeal counterparts.
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Affiliation(s)
- Prashanth Vishwanath
- BioMolecular Engineering Research Center, Boston University, 36 Cummington St., Boston, MA 02215, USA
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39
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De Rosa Jr. VE, Nogueira FTS, Menossi M, Ulian EC, Arruda P. Identification of methyl jasmonate-responsive genes in sugarcane using cDNA arrays. ACTA ACUST UNITED AC 2005. [DOI: 10.1590/s1677-04202005000100014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Jasmonic acid (JA) and its ester methyl jasmonate (MeJA) are linolenic acid-derived signaling molecules involved in plant development and stress responses. MeJA regulates gene expression at transcription, RNA processing and translation. We investigated the changes in gene expression in sugarcane leaves exposed to MeJA using cDNA arrays. Total RNA isolated at 0, 0.5, 1, 3, 6, and 12 h following MeJA treatment was labeled with alpha-33P-dCTP and hybridized to nylon filters containing 1,536 cDNA clones. A significant increase in gene expression in response to MeJA was detected for both novel and well known stress-related genes, while genes participating in photosynthesis and carbohydrate assimilation were down-regulated. Searches for conserved domains in unknown proteins and digital mRNA expression profile analysis revealed putative new stress-related proteins up-regulated by MeJA and the tissues where the MeJA-regulated genes are preferably expressed.
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Affiliation(s)
| | - Fábio T. S. Nogueira
- Universidade Estadual de Campinas, Brazil; Universidade Estadual de Campinas, Brazil
| | - Marcelo Menossi
- Universidade Estadual de Campinas, Brazil; Universidade Estadual de Campinas, Brazil
| | | | - Paulo Arruda
- Universidade Estadual de Campinas, Brazil; Universidade Estadual de Campinas, Brazil
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40
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Hoang L, Fredrick K, Noller HF. Creating ribosomes with an all-RNA 30S subunit P site. Proc Natl Acad Sci U S A 2004; 101:12439-43. [PMID: 15308780 PMCID: PMC515080 DOI: 10.1073/pnas.0405227101] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ribosome crystal structures have revealed that two small subunit proteins, S9 and S13, have C-terminal tails, which, together with several features of 16S rRNA, contact the anticodon stem-loop of P-site tRNA. To test the functional importance of these protein tails, we created genomic deletions of the C-terminal regions of S9 and S13. All of the tail deletions, including double mutants containing deletions in both S9 and S13, were viable, showing that Escherichia coli cells can synthesize all of their proteins by using ribosomes that contain 30S P sites composed only of RNA. However, these mutants have slower growth rates, indicating that the tails may play a supporting functional role in translation. In vitro analysis shows that 30S subunits purified from the S13 deletion mutants have a generally decreased affinity for tRNA, whereas deletion of the S9 tail selectively affects the binding of tRNAs whose anticodon stem sequences are most divergent from that of initiator tRNA.
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Affiliation(s)
- Lee Hoang
- Department of Molecular, Cell, and Developmental Biology and Center for Molecular Biology of RNA, University of California, Santa Cruz, CA 95064, USA
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41
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Abstract
Antimicrobial resistance is a growing problem among pathogens from respiratory tract infections. b-Lactam resistance rates are escalating among Streptococcus pneumoniae and Haemophilus influenzae. Macrolides are increasingly used for the treatment of respiratory tract infections, but their utility is compromised by intrinsic and acquired resistance. This article analyses macrolide-resistance mechanisms and their worldwide distributions in S pneumoniae, S pyogenes, and H influenzae.
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Affiliation(s)
- Bülent Bozdogan
- Department of Pathology, Hershey Medical Center, 500 University Drive, Pennsylvania State University, Hershey, PA 17033, USA.
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Jakovljevic J, de Mayolo PA, Miles TD, Nguyen TML, Léger-Silvestre I, Gas N, Woolford JL. The carboxy-terminal extension of yeast ribosomal protein S14 is necessary for maturation of 43S preribosomes. Mol Cell 2004; 14:331-42. [PMID: 15125836 DOI: 10.1016/s1097-2765(04)00215-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Revised: 03/17/2004] [Accepted: 03/25/2004] [Indexed: 10/26/2022]
Abstract
Eukaryotic ribosomal proteins are required for production of stable ribosome assembly intermediates and mature ribosomes, but more specific roles for these proteins in biogenesis of ribosomes are not known. Here we demonstrate a particular function for yeast ribosomal protein rpS14 in late steps of 40S ribosomal subunit maturation and pre-rRNA processing. Extraordinary amounts of 43S preribosomes containing 20S pre-rRNA accumulate in the cytoplasm of certain rps14 mutants. These mutations not only reveal a more precise function for rpS14 in ribosome biogenesis but also uncover a role in ribosome assembly for the extended tails found in many ribosomal proteins. These studies are one of the first to relate the structure of eukaryotic ribosomes to their assembly pathway-the carboxy-terminal extension of rpS14 is located in the 40S subunit near the 3' end of 18S rRNA, consistent with a role for rpS14 in 3' end processing of 20S pre-rRNA.
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Affiliation(s)
- Jelena Jakovljevic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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