1
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Millette G, Séguin DL, Isabelle C, Chamberland S, Lucier JF, Rodrigue S, Cantin AM, Malouin F. Staphylococcus aureus Small-Colony Variants from Airways of Adult Cystic Fibrosis Patients as Precursors of Adaptive Antibiotic-Resistant Mutations. Antibiotics (Basel) 2023; 12:1069. [PMID: 37370388 PMCID: PMC10294822 DOI: 10.3390/antibiotics12061069] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Prototypic Staphylococcus aureus and their small-colony variants (SCVs) are predominant in cystic fibrosis (CF), but the interdependence of these phenotypes is poorly understood. We characterized S. aureus isolates from adult CF patients over several years. Of 18 S. aureus-positive patients (58%), 13 (72%) were positive for SCVs. Characterization included genotyping, SCCmec types, auxotrophy, biofilm production, antibiotic susceptibilities and tolerance, and resistance acquisition rates. Whole-genome sequencing revealed that several patients were colonized with prototypical and SCV-related clones. Some clonal pairs showed acquisition of aminoglycoside resistance that was not explained by aminoglycoside-modifying enzymes, suggesting a mutation-based process. The characteristics of SCVs that could play a role in resistance acquisition were thus investigated further. For instance, SCV isolates produced more biofilm (p < 0.05) and showed a higher survival rate upon exposure to ciprofloxacin and vancomycin compared to their prototypic associated clones. SCVs also developed spontaneous rifampicin resistance mutations at a higher frequency. Accordingly, a laboratory-derived SCV (ΔhemB) acquired resistance to ciprofloxacin and gentamicin faster than its parent counterpart after serial passages in the presence of sub-inhibitory concentrations of antibiotics. These results suggest a role for SCVs in the establishment of persistent antibiotic-resistant clones in adult CF patients.
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Affiliation(s)
- Guillaume Millette
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - David Lalonde Séguin
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - Charles Isabelle
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - Suzanne Chamberland
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - Jean-François Lucier
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - Sébastien Rodrigue
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
| | - André M. Cantin
- Service de Pneumologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada;
| | - François Malouin
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (D.L.S.); (C.I.); (S.C.); (J.-F.L.); (S.R.)
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2
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Naganathan A, Culver GM. Interdependency and Redundancy Add Complexity and Resilience to Biogenesis of Bacterial Ribosomes. Annu Rev Microbiol 2022; 76:193-210. [PMID: 35609945 DOI: 10.1146/annurev-micro-041020-121806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pace and efficiency of ribosomal subunit production directly impact the fitness of bacteria. Biogenesis demands more than just the union of ribosomal components, including RNA and proteins, to form this functional ribonucleoprotein particle. Extra-ribosomal protein factors play a fundamental role in the efficiency and efficacy of ribosomal subunit biogenesis. A paucity of data on intermediate steps, multiple and overlapping pathways, and the puzzling number of functions that extra-ribosomal proteins appear to play in vivo make unraveling the formation of this macromolecular assemblage difficult. In this review, we outline with examples the multinodal landscape of factor-assisted mechanisms that influence ribosome synthesis in bacteria. We discuss in detail late-stage events that mediate correct ribosome formation and the transition to translation initiation and thereby ensure high-fidelity protein synthesis.
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Affiliation(s)
- Anusha Naganathan
- Department of Biology, University of Rochester, Rochester, New York, USA; ,
| | - Gloria M Culver
- Department of Biology, University of Rochester, Rochester, New York, USA; ,
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York, USA
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3
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Lu C, Zhang N, Kou S, Gao L, Peng B, Dai Y, Zheng J. Sanguinarine synergistically potentiates aminoglycoside-mediated bacterial killing. Microb Biotechnol 2022; 15:2055-2070. [PMID: 35318794 PMCID: PMC9249330 DOI: 10.1111/1751-7915.14017] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/01/2022] [Indexed: 11/30/2022] Open
Abstract
Aminoglycosides are one of the oldest classes of antimicrobials that are being used in current clinical practice, especially on multi‐drug resistant Gram‐negative pathogenic bacteria. However, the serious side effects at high dosage such as ototoxicity, neuropathy and nephrotoxicity limit their applications in clinical practice. Approaches that potentiate aminoglycoside killing could lower down their effective concentrations to a non‐toxic dosage for clinical treatment. In this research, we screened a compound library and identified sanguinarine that acts synergistically with various aminoglycosides. By checkerboard and dynamical killing assay, we found that sanguinarine effectively potentiated aminoglycoside killing on diverse bacterial pathogens, including Escherichia coli, Acinetobacter baumannii, Klebsiella pneumonia and Pseudomonas aeruginosa. The mechanistic studies showed an elevated intracellular ROS and DNA oxidative level in the bacterial cells treated by a combination of sanguinarine with aminoglycosides. Furthermore, an enhanced level of sanguinarine was observed in bacteria in the presence of aminoglycosides, suggesting that aminoglycosides promote the uptake of sanguinarine. Importantly, sanguinarine was shown to promote the elimination of persister cells and established biofilm cells both in vivo and in vitro. Our study provides a novel insight for approaches to lower down the clinical dosages of aminoglycosides.
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Affiliation(s)
- Chang Lu
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Nian Zhang
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Sihoi Kou
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Liangliang Gao
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Bo Peng
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Yunlu Dai
- Faculty of Health Sciences, University of Macau, Macau, China.,Institute of Translational Medicine, University of Macau, Macau, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau, China.,Institute of Translational Medicine, University of Macau, Macau, China
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4
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Shen H, Gonskikh Y, Stoute J, Liu KF. Human DIMT1 generates N 26,6A-dimethylation-containing small RNAs. J Biol Chem 2021; 297:101146. [PMID: 34473991 PMCID: PMC8463865 DOI: 10.1016/j.jbc.2021.101146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022] Open
Abstract
Dimethyladenosine transferase 1 (DIMT1) is an evolutionarily conserved RNA N6,6-dimethyladenosine (m26,6A) methyltransferase. DIMT1 plays an important role in ribosome biogenesis, and the catalytic activity of DIMT1 is indispensable for cell viability and protein synthesis. A few RNA-modifying enzymes can install the same modification in multiple RNA species. However, whether DIMT1 can work on RNA species other than 18S rRNA is unclear. Here, we describe that DIMT1 generates m26,6A not only in 18S rRNA but also in small RNAs. In addition, m26,6A in small RNAs were significantly decreased in cells expressing catalytically inactive DIMT1 variants (E85A or NLPY variants) compared with cells expressing wildtype DIMT1. Both E85A and NLPY DIMT1 variant cells present decreased protein synthesis and cell viability. Furthermore, we observed that DIMT1 is highly expressed in human cancers, including acute myeloid leukemia. Our data suggest that downregulation of DIMT1 in acute myeloid leukemia cells leads to a decreased m26,6A level in small RNAs. Together, these data suggest that DIMT1 not only installs m26,6A in 18S rRNA but also generates m26,6A-containing small RNAs, both of which potentially contribute to the impact of DIMT1 on cell viability and gene expression.
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Affiliation(s)
- Hui Shen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yulia Gonskikh
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Julian Stoute
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kathy Fange Liu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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5
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Carvalho A, Mazel D, Baharoglu Z. Deficiency in cytosine DNA methylation leads to high chaperonin expression and tolerance to aminoglycosides in Vibrio cholerae. PLoS Genet 2021; 17:e1009748. [PMID: 34669693 PMCID: PMC8559950 DOI: 10.1371/journal.pgen.1009748] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/01/2021] [Accepted: 10/04/2021] [Indexed: 12/11/2022] Open
Abstract
Antibiotic resistance has become a major global issue. Understanding the molecular mechanisms underlying microbial adaptation to antibiotics is of keen importance to fight Antimicrobial Resistance (AMR). Aminoglycosides are a class of antibiotics that target the small subunit of the bacterial ribosome, disrupting translational fidelity and increasing the levels of misfolded proteins in the cell. In this work, we investigated the role of VchM, a DNA methyltransferase, in the response of the human pathogen Vibrio cholerae to aminoglycosides. VchM is a V. cholerae specific orphan m5C DNA methyltransferase that generates cytosine methylation at 5'-RCCGGY-3' motifs. We show that deletion of vchM, although causing a growth defect in absence of stress, allows V. cholerae cells to cope with aminoglycoside stress at both sub-lethal and lethal concentrations of these antibiotics. Through transcriptomic and genetic approaches, we show that groESL-2 (a specific set of chaperonin-encoding genes located on the second chromosome of V. cholerae), are upregulated in cells lacking vchM and are needed for the tolerance of vchM mutant to lethal aminoglycoside treatment, likely by fighting aminoglycoside-induced misfolded proteins. Interestingly, preventing VchM methylation of the four RCCGGY sites located in groESL-2 region, leads to a higher expression of these genes in WT cells, showing that the expression of these chaperonins is modulated in V. cholerae by DNA methylation.
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Affiliation(s)
- André Carvalho
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, Collège doctoral, F-75005 Paris, France
| | - Didier Mazel
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
| | - Zeynep Baharoglu
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
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6
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Abstract
The spread of antibiotic resistance is turning many of the currently used antibiotics less effective against common infections. To address this public health challenge, it is critical to enhance our understanding of the mechanisms of action of these compounds. Aminoglycoside drugs bind the bacterial ribosome, and decades of results from in vitro biochemical and structural approaches suggest that these drugs disrupt protein synthesis by inhibiting the ribosome's translocation on the messenger RNA, as well as by inducing miscoding errors. So far, however, we have sparse information about the dynamic effects of these compounds on protein synthesis inside the cell. In the present study, we measured the effect of the aminoglycosides apramycin, gentamicin, and paromomycin on ongoing protein synthesis directly in live Escherichia coli cells by tracking the binding of dye-labeled transfer RNAs to ribosomes. Our results suggest that the drugs slow down translation elongation two- to fourfold in general, and the number of elongation cycles per initiation event seems to decrease to the same extent. Hence, our results imply that none of the drugs used in this study cause severe inhibition of translocation.
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7
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Prediction of Streptococcus uberis clinical mastitis treatment success in dairy herds by means of mass spectrometry and machine-learning. Sci Rep 2021; 11:7736. [PMID: 33833319 PMCID: PMC8032699 DOI: 10.1038/s41598-021-87300-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/26/2021] [Indexed: 12/26/2022] Open
Abstract
Streptococcus uberis is one of the leading pathogens causing mastitis worldwide. Identification of S. uberis strains that fail to respond to treatment with antibiotics is essential for better decision making and treatment selection. We demonstrate that the combination of supervised machine learning and matrix-assisted laser desorption ionization/time of flight (MALDI-TOF) mass spectrometry can discriminate strains of S. uberis causing clinical mastitis that are likely to be responsive or unresponsive to treatment. Diagnostics prediction systems trained on 90 individuals from 26 different farms achieved up to 86.2% and 71.5% in terms of accuracy and Cohen’s kappa. The performance was further increased by adding metadata (parity, somatic cell count of previous lactation and count of positive mastitis cases) to encoded MALDI-TOF spectra, which increased accuracy and Cohen’s kappa to 92.2% and 84.1% respectively. A computational framework integrating protein–protein networks and structural protein information to the machine learning results unveiled the molecular determinants underlying the responsive and unresponsive phenotypes.
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8
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Zou J, Kou SH, Xie R, VanNieuwenhze MS, Qu J, Peng B, Zheng J. Non-walled spherical Acinetobacter baumannii is an important type of persister upon β-lactam antibiotic treatment. Emerg Microbes Infect 2021; 9:1149-1159. [PMID: 32419626 PMCID: PMC7448848 DOI: 10.1080/22221751.2020.1770630] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacterial persistence is one of the major causes of antibiotic treatment failure and the step stone for antibiotic resistance. However, the mechanism by which persisters arise has not been well understood. Maintaining a dormant state to prevent antibiotics from taking effect is believed to be the fundamental mechanistic basis, and persisters normally maintain an intact cellular structure. Here we examined the morphologies of persisters in Acinetobacter baumannii survived from the treatment by three major classes of antibiotics (i.e. β-lactam, aminoglycoside, and fluoroquinolone) with microcopy and found that a fraction of enlarged spherical bacteria constitutes a major sub-population of bacterial survivors from β-lactam antibiotic treatment, whereas survivors from the treatment of aminoglycoside and fluoroquinolone were less changed morphologically. Further studies showed that these spherical bacteria had completely lost their cell wall structures but could survive without any osmoprotective reagent. The spherical bacteria were not the viable-but-non-culturable cells and they could revive upon the removal of β-lactam antibiotics. Importantly, these non-walled spherical bacteria also persisted during antibiotic therapy in vivo using Galleria mellonella as the infection model. Additionally, the combinational treatment on A. baumannii by β-lactam and membrane-targeting antibiotic significantly enhanced the killing efficacy. Our results indicate that in addition to the dormant, structure intact persisters, the non-wall spherical bacterium is another important type of persister in A. baumannii. The finding suggests that targeting the bacterial cell membrane during β-lactam chemotherapy could enhance therapeutic efficacy on A. baumannii infection, which might also help to reduce the resistance development of A. baumannii.
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Affiliation(s)
- Jin Zou
- Faculty of Health Sciences, University of Macau, Macau SAR, People's Republic of China
| | - Si-Hoi Kou
- Faculty of Health Sciences, University of Macau, Macau SAR, People's Republic of China
| | - Ruiqiang Xie
- Faculty of Health Sciences, University of Macau, Macau SAR, People's Republic of China
| | | | - Jiuxin Qu
- Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Southern University of Science and Technology, National Clinical Research Center for Infectious Diseases, Shenzhen, People's Republic of China
| | - Bo Peng
- School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau SAR, People's Republic of China.,Institute of Translational Medicine, University of Macau, Macau SAR, People's Republic of China
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9
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Xie R, Shao N, Zheng J. Integrated Co-functional Network Analysis on the Resistance and Virulence Features in Acinetobacter baumannii. Front Microbiol 2020; 11:598380. [PMID: 33224132 PMCID: PMC7667040 DOI: 10.3389/fmicb.2020.598380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022] Open
Abstract
Acinetobacter baumannii is one of the most troublesome bacterial pathogens that pose major public health threats due to its rapidly increasing drug resistance property. It is not only derived from clinic setting but also emerges from aquaculture as a fish pathogen, which could pass the resistant genes in the food chain. Understanding the mechanism of antibiotic resistance development and pathogenesis will aid our battle with the infections caused by A. baumannii. In this study, we constructed a co-functional network by integrating multiple sources of data from A. baumannii and then used the k-shell decomposition to analyze the co-functional network. We found that genes involving in basic cellular physiological function, including genes for antibiotic resistance, tended to have high k-shell values and locate in the internal layer of our network. In contrast, the non-essential genes, such as genes associated with virulence, tended to have lower k-shell values and locate in the external layer. This finding allows us to fish out the potential antibiotic resistance factors and virulence factors. In addition, we constructed an online platform ABviresDB (https://acba.shinyapps.io/ABviresDB/) for visualization of the network and features of each gene in A. baumannii. The network analysis in this study will not only aid the study on A. baumannii but also could be referenced for the research of antibiotic resistance and pathogenesis in other bacteria.
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Affiliation(s)
- Ruiqiang Xie
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Ningyi Shao
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau, China.,Institute of Translational Medicine, University of Macau, Macau, China
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10
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Watson ZL, Ward FR, Méheust R, Ad O, Schepartz A, Banfield JF, Cate JH. Structure of the bacterial ribosome at 2 Å resolution. eLife 2020; 9:60482. [PMID: 32924932 DOI: 10.1101/2020.06.26.174334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/11/2020] [Indexed: 05/24/2023] Open
Abstract
Using cryo-electron microscopy (cryo-EM), we determined the structure of the Escherichia coli 70S ribosome with a global resolution of 2.0 Å. The maps reveal unambiguous positioning of protein and RNA residues, their detailed chemical interactions, and chemical modifications. Notable features include the first examples of isopeptide and thioamide backbone substitutions in ribosomal proteins, the former likely conserved in all domains of life. The maps also reveal extensive solvation of the small (30S) ribosomal subunit, and interactions with A-site and P-site tRNAs, mRNA, and the antibiotic paromomycin. The maps and models of the bacterial ribosome presented here now allow a deeper phylogenetic analysis of ribosomal components including structural conservation to the level of solvation. The high quality of the maps should enable future structural analyses of the chemical basis for translation and aid the development of robust tools for cryo-EM structure modeling and refinement.
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Affiliation(s)
- Zoe L Watson
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Fred R Ward
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Raphaël Méheust
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, United States
- Earth and Planetary Science, University of California, Berkeley, Berkeley, United States
| | - Omer Ad
- Department of Chemistry, Yale University, New Haven, United States
| | - Alanna Schepartz
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jillian F Banfield
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, United States
- Earth and Planetary Science, University of California, Berkeley, Berkeley, United States
- Environmental Science, Policy and Management, University of California Berkeley, Berkeley, United States
| | - Jamie Hd Cate
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States
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11
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Watson ZL, Ward FR, Méheust R, Ad O, Schepartz A, Banfield JF, Cate JHD. Structure of the bacterial ribosome at 2 Å resolution. eLife 2020; 9:e60482. [PMID: 32924932 PMCID: PMC7550191 DOI: 10.7554/elife.60482] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/11/2020] [Indexed: 12/31/2022] Open
Abstract
Using cryo-electron microscopy (cryo-EM), we determined the structure of the Escherichia coli 70S ribosome with a global resolution of 2.0 Å. The maps reveal unambiguous positioning of protein and RNA residues, their detailed chemical interactions, and chemical modifications. Notable features include the first examples of isopeptide and thioamide backbone substitutions in ribosomal proteins, the former likely conserved in all domains of life. The maps also reveal extensive solvation of the small (30S) ribosomal subunit, and interactions with A-site and P-site tRNAs, mRNA, and the antibiotic paromomycin. The maps and models of the bacterial ribosome presented here now allow a deeper phylogenetic analysis of ribosomal components including structural conservation to the level of solvation. The high quality of the maps should enable future structural analyses of the chemical basis for translation and aid the development of robust tools for cryo-EM structure modeling and refinement.
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Affiliation(s)
- Zoe L Watson
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Fred R Ward
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Raphaël Méheust
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- Earth and Planetary Science, University of California, BerkeleyBerkeleyUnited States
| | - Omer Ad
- Department of Chemistry, Yale UniversityNew HavenUnited States
| | - Alanna Schepartz
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Jillian F Banfield
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- Earth and Planetary Science, University of California, BerkeleyBerkeleyUnited States
- Environmental Science, Policy and Management, University of California BerkeleyBerkeleyUnited States
| | - Jamie HD Cate
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
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12
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Shen H, Stoute J, Liu KF. Structural and catalytic roles of the human 18 S rRNA methyltransferases DIMT1 in ribosome assembly and translation. J Biol Chem 2020; 295:12058-12070. [PMID: 32616653 PMCID: PMC7443495 DOI: 10.1074/jbc.ra120.014236] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/26/2020] [Indexed: 12/25/2022] Open
Abstract
rRNA-modifying enzymes participate in ribosome assembly. However, whether the catalytic activities of these enzymes are important for the ribosome assembly and other cellular processes is not fully understood. Here, we report the crystal structure of WT human dimethyladenosine transferase 1 (DIMT1), an 18S rRNA N6,6-dimethyladenosine (m26,6A) methyltransferase, and results obtained with a catalytically inactive DIMT1 variant. We found that DIMT1+/- heterozygous HEK 293T cells have a significantly decreased 40S fraction and reduced protein synthesis but no major changes in m26,6A levels in 18S rRNA. Expression of a catalytically inactive variant, DIMT1-E85A, in WT and DIMT1+/- cells significantly decreased m26,6A levels in 18S rRNA, indicating a dominant-negative effect of this variant on m26,6A levels. However, expression of the DIMT1-E85A variant restored the defects in 40S levels. Of note, unlike WT DIMT1, DIMT1-E85A could not revert the defects in protein translation. We found that the differences between this variant and the WT enzyme extended to translation fidelity and gene expression patterns in DNA damage response pathways. These results suggest that the catalytic activity of DIMT1 is involved in protein translation and that the overall protein scaffold of DIMT1, regardless of the catalytic activity on m26,6A in 18S rRNA, is essential for 40S assembly.
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MESH Headings
- Amino Acid Substitution
- Catalysis
- Crystallography, X-Ray
- HEK293 Cells
- Humans
- Methyltransferases/chemistry
- Methyltransferases/genetics
- Methyltransferases/metabolism
- Mutation, Missense
- Protein Biosynthesis
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- Ribosome Subunits, Small, Eukaryotic/chemistry
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
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Affiliation(s)
- Hui Shen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Julian Stoute
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kathy Fange Liu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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13
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Meng L, Liu H, Lan T, Dong L, Hu H, Zhao S, Zhang Y, Zheng N, Wang J. Antibiotic Resistance Patterns of Pseudomonas spp. Isolated From Raw Milk Revealed by Whole Genome Sequencing. Front Microbiol 2020; 11:1005. [PMID: 32655503 PMCID: PMC7326020 DOI: 10.3389/fmicb.2020.01005] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/24/2020] [Indexed: 12/11/2022] Open
Abstract
Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and the economic losses they cause to the dairy industry. Food-related psychrotrophic bacteria are increasingly reported to have antibiotic resistance features. The aim of this study was to evaluate the resistance patterns of Pseudomonas spp. isolated from bulk-tank milk. In total, we investigated the antibiotic susceptibility profiles of 86 Pseudomonas spp. isolates from raw milk. All strains were tested against 15 antimicrobial agents. Pseudomonas isolates were most highly resistant to imipenem (95.3%), followed by trimethoprim-sulfamethoxazole (69.8%), aztreonam (60.5%), chloramphenicol (45.3%), and meropenem (27.9%). Their multiple antibiotic resistance (MAR) index values ranged from 0.0 to 0.8. Whole-genome sequencing revealed the presence of intrinsic resistance determinants, such as BcI, ampC-09, blaCTX-M, oprD, sul1, dfrE, catA1, catB3, catI, floR, and cmlV. Moreover, resistance-nodulation-cell division (RND) and ATP-binding cassette (ABC) antibiotic efflux pumps were also found. This study provides further knowledge of the antibiotic resistance patterns of Pseudomonas spp. in milk, which may advance our understanding of resistance in Pseudomonas and suggests that antibiotic resistance of Pseudomonas spp. in raw milk should be a concern.
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Affiliation(s)
- Lu Meng
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huimin Liu
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tu Lan
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lei Dong
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haiyan Hu
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Shengguo Zhao
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yangdong Zhang
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Nan Zheng
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiaqi Wang
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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14
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Xu X, Zhang H, Huang Y, Zhang Y, Wu C, Gao P, Teng Z, Luo X, Peng X, Wang X, Wang D, Pu J, Zhao H, Lu X, Lu S, Ye C, Dong Y, Lan R, Xu J. Beyond a Ribosomal RNA Methyltransferase, the Wider Role of MraW in DNA Methylation, Motility and Colonization in Escherichia coli O157:H7. Front Microbiol 2019; 10:2520. [PMID: 31798540 PMCID: PMC6863780 DOI: 10.3389/fmicb.2019.02520] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/18/2019] [Indexed: 12/31/2022] Open
Abstract
MraW is a 16S rRNA methyltransferase and plays a role in the fine-tuning of the ribosomal decoding center. It was recently found to contribute to the virulence of Staphylococcus aureus. In this study, we examined the function of MraW in Escherichia coli O157:H7 and found that the deletion of mraW led to decreased motility, flagellar production and DNA methylation. Whole-genome bisulfite sequencing showed a genome wide decrease of methylation of 336 genes and 219 promoters in the mraW mutant including flagellar genes. The methylation level of flagellar genes was confirmed by bisulfite PCR sequencing. Quantitative reverse transcription PCR results indicated that the transcription of these genes was also affected. MraW was furtherly observed to directly bind to the four flagellar gene sequences by electrophoretic mobility shift assay (EMSA). A common flexible motif in differentially methylated regions (DMRs) of promoters and coding regions of the four flagellar genes was identified. Reduced methylation was correlated with altered expression of 21 of the 24 genes tested. DNA methylation activity of MraW was confirmed by DNA methyltransferase activity assay in vitro and repressed by DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza). In addition, the mraW mutant colonized poorer than wild type in mice. We also found that the expression of mraZ in the mraW mutant was increased confirming the antagonistic effect of mraW on mraZ. In conclusion, mraW was found to be a DNA methylase and have a wide-ranging effect on E. coli O157:H7 including motility and virulence in vivo via genome wide methylation and mraZ antagonism.
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Affiliation(s)
- Xuefang Xu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Heng Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Ying Huang
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yuan Zhang
- China Institute of Veterinary Drug Control, Haidian, China
| | - Changde Wu
- College of Animal Sciences and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Pengya Gao
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,College of Animal Sciences and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Zhongqiu Teng
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xuelian Luo
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xiaojing Peng
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xiaoyuan Wang
- Heilongjiang University of Chinese Medicine, Harbin, China
| | - Dai Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China
| | - Ji Pu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Hongqing Zhao
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xuancheng Lu
- Laboratory Animal Center, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Shuangshuang Lu
- Laboratory Animal Center, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Changyun Ye
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yuhui Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control and National Institute for Communicable Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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15
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Alarmone Ap4A is elevated by aminoglycoside antibiotics and enhances their bactericidal activity. Proc Natl Acad Sci U S A 2019; 116:9578-9585. [PMID: 31004054 PMCID: PMC6511005 DOI: 10.1073/pnas.1822026116] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This paper demonstrates that aminoglycoside antibiotics induce the production of the Ap4A in bacteria. Increased intracellular Ap4A, in turn, promotes bacterial cell killing by this class of antibiotics, which correlated well with elevated damage to the bacterial membrane upon aminoglycoside treatment. These findings reveal a striking connection between aminoglycoside killing and the Ap4A production particularly under conditions of oxidative stress. Importantly, the results of this study suggest that targeting Ap4A degradation or inducing its hypersynthesis during therapy with aminoglycosides might help solve the well-known toxicity issue associated with this class of antibiotics by reducing the level of drug needed for effective treatment. Second messenger molecules play important roles in the responses to various stimuli that can determine a cell's fate under stress conditions. Here, we report that lethal concentrations of aminoglycoside antibiotics result in the production of a dinucleotide alarmone metabolite–diadenosine tetraphosphate (Ap4A), which promotes bacterial cell killing by this class of antibiotics. We show that the treatment of Escherichia coli with lethal concentrations of kanamycin (Kan) dramatically increases the production of Ap4A. This elevation of Ap4A is dependent on the production of a hydroxyl radical and involves the induction of the Ap4A synthetase lysyl-tRNA synthetase (LysU). Ectopic alteration of intracellular Ap4A concentration via the elimination of the Ap4A phosphatase diadenosine tetraphosphatase (ApaH) and the overexpression of LysU causes over a 5,000-fold increase in bacterial killing by aminoglycosides. This increased susceptibility to aminoglycosides correlates with bacterial membrane disruption. Our findings provide a role for the alarmone Ap4A and suggest that blocking Ap4A degradation or increasing its synthesis might constitute an approach to enhance aminoglycoside killing potency by broadening their therapeutic index and thereby allowing lower nontoxic dosages of these antibiotics to be used in the treatment of multidrug-resistant infections.
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