1
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Lemay-St-Denis C, Pelletier JN. From a binding module to essential catalytic activity: how nature stumbled on a good thing. Chem Commun (Camb) 2023; 59:12560-12572. [PMID: 37791701 DOI: 10.1039/d3cc04209j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Enzymes are complex macromolecules capable of catalyzing a wide variety of chemical reactions with high efficiency. Nonetheless, biological catalysis can be rudimentary. Here, we describe an enzyme that is built from a simple protein fold. This short protein sequence - almost a peptide - belongs to the ancient SH3 family of binding modules. Surprisingly, this binding module catalyzes the specific reduction of dihydrofolate using NADPH as a reducing cofactor, making this a dihydrofolate reductase. Too small to provide all the required binding and catalytic machinery on its own, it homotetramerizes, thus creating a large, central active site environment. Remarkably, none of the active site residues is essential to the catalytic function. Instead, backbone interactions juxtapose the reducing cofactor proximal to the target imine of the folate substrate, and a specific motion of the substrate promotes formation of the transition state. In this feature article, we describe the features that make this small protein a functional enzyme capable of catalyzing a metabolically essential reaction, highlighting the characteristics that make it a model for the evolution of primitive enzymes from binding modules.
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Affiliation(s)
- Claudèle Lemay-St-Denis
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Quebec, QC, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montreal, QC, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, QC, Canada
| | - Joelle N Pelletier
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Quebec, QC, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montreal, QC, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, QC, Canada
- Chemistry Department, Université de Montréal, Montreal, QC, Canada.
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2
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Wang X, Zhang M, Zhu T, Wei Q, Liu G, Ding J. Flourishing Antibacterial Strategies for Osteomyelitis Therapy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206154. [PMID: 36717275 PMCID: PMC10104653 DOI: 10.1002/advs.202206154] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/05/2022] [Indexed: 06/18/2023]
Abstract
Osteomyelitis is a destructive disease of bone tissue caused by infection with pathogenic microorganisms. Because of the complex and long-term abnormal conditions, osteomyelitis is one of the refractory diseases in orthopedics. Currently, anti-infective therapy is the primary modality for osteomyelitis therapy in addition to thorough surgical debridement. However, bacterial resistance has gradually reduced the benefits of traditional antibiotics, and the development of advanced antibacterial agents has received growing attention. This review introduces the main targets of antibacterial agents for treating osteomyelitis, including bacterial cell wall, cell membrane, intracellular macromolecules, and bacterial energy metabolism, focuses on their mechanisms, and predicts prospects for clinical applications.
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Affiliation(s)
- Xukai Wang
- Department of Thoracic SurgeryChina‐Japan Union Hospital of Jilin University126 Xiantai StreetChangchun130033P. R. China
- Key Laboratory of Polymer EcomaterialsChangchun Institute of Applied ChemistryChinese Academy of Sciences5625 Renmin StreetChangchun130022P. R. China
| | - Mingran Zhang
- Department of Thoracic SurgeryChina‐Japan Union Hospital of Jilin University126 Xiantai StreetChangchun130033P. R. China
| | - Tongtong Zhu
- Department of Thoracic SurgeryChina‐Japan Union Hospital of Jilin University126 Xiantai StreetChangchun130033P. R. China
| | - Qiuhua Wei
- Department of Disinfection and Infection ControlChinese PLA Center for Disease Control and Prevention20 Dongda StreetBeijing100071P. R. China
| | - Guangyao Liu
- Department of Thoracic SurgeryChina‐Japan Union Hospital of Jilin University126 Xiantai StreetChangchun130033P. R. China
| | - Jianxun Ding
- Key Laboratory of Polymer EcomaterialsChangchun Institute of Applied ChemistryChinese Academy of Sciences5625 Renmin StreetChangchun130022P. R. China
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3
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Lemay-St-Denis C, Alejaldre L, Jemouai Z, Lafontaine K, St-Aubin M, Hitache K, Valikhani D, Weerasinghe NW, Létourneau M, Thibodeaux CJ, Doucet N, Baron C, Copp JN, Pelletier JN. A conserved SH3-like fold in diverse putative proteins tetramerizes into an oxidoreductase providing an antimicrobial resistance phenotype. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220040. [PMID: 36633286 PMCID: PMC9835603 DOI: 10.1098/rstb.2022.0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We present a potential mechanism for emergence of catalytic activity that is essential for survival, from a non-catalytic protein fold. The type B dihydrofolate reductase (DfrB) family of enzymes were first identified in pathogenic bacteria because their dihydrofolate reductase activity is sufficient to provide trimethoprim (TMP) resistance. DfrB enzymes are described as poorly evolved as a result of their unusual structural and kinetic features. No characterized protein shares sequence homology with DfrB enzymes; how they evolved to emerge in the modern resistome is unknown. In this work, we identify DfrB homologues from a database of putative and uncharacterized proteins. These proteins include an SH3-like fold homologous to the DfrB enzymes, embedded in a variety of additional structural domains. By means of functional, structural and biophysical characterization, we demonstrate that these distant homologues and their extracted SH3-like fold can display dihydrofolate reductase activity and confer TMP resistance. We provide evidence of tetrameric assembly and catalytic mechanism analogous to that of DfrB enzymes. These results contribute, to our knowledge, the first insights into a potential evolutionary path taken by this SH3-like fold to emerge in the modern resistome following introduction of TMP. This article is part of the theme issue 'Reactivity and mechanism in chemical and synthetic biology'.
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Affiliation(s)
- Claudèle Lemay-St-Denis
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Lorea Alejaldre
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Zakaria Jemouai
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Kiana Lafontaine
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Maxime St-Aubin
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Katia Hitache
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Donya Valikhani
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Chemistry Department, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Nuwani W. Weerasinghe
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec H3A 0B8, Canada
| | - Myriam Létourneau
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université du Québec, Laval, Québec H7V 1B7, Canada
| | - Christopher J. Thibodeaux
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec H3A 0B8, Canada
| | - Nicolas Doucet
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université du Québec, Laval, Québec H7V 1B7, Canada
| | - Christian Baron
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Janine N. Copp
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Joelle N. Pelletier
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, Québec G1V 0A6, Canada,CGCC, Center in Green Chemistry and Catalysis, Montréal, Québec H2V 0B3, Canada,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada,Chemistry Department, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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4
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Cellier-Goetghebeur S, Lafontaine K, Lemay-St-Denis C, Tsamo P, Bonneau-Burke A, Copp JN, Pelletier JN. Discovery of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases in Diverse Environmental Settings Suggests an Evolutionary Advantage Unrelated to Antibiotic Resistance. Antibiotics (Basel) 2022; 11:antibiotics11121768. [PMID: 36551425 PMCID: PMC9774602 DOI: 10.3390/antibiotics11121768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022] Open
Abstract
Type B dihydrofolate reductases (DfrB) are intrinsically highly resistant to the widely used antibiotic trimethoprim, posing a threat to global public health. The ten known DfrB family members have been strongly associated with genetic material related to the application of antibiotics. Several dfrB genes were associated with multidrug resistance contexts and mobile genetic elements, integrated both in chromosomes and plasmids. However, little is known regarding their presence in other environments. Here, we investigated the presence of dfrB beyond the traditional areas of enquiry by conducting metagenomic database searches from environmental settings where antibiotics are not prevalent. Thirty putative DfrB homologues that share 62 to 95% identity with characterized DfrB were identified. Expression of ten representative homologues verified trimethoprim resistance in all and dihydrofolate reductase activity in most. Contrary to samples associated with the use of antibiotics, the newly identified dfrB were rarely associated with mobile genetic elements or antibiotic resistance genes. Instead, association with metabolic enzymes was observed, suggesting an evolutionary advantage unrelated to antibiotic resistance. Our results are consistent with the hypothesis that multiple dfrB exist in diverse environments from which dfrB were mobilized into the clinically relevant resistome. Our observations reinforce the need to closely monitor their progression.
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Affiliation(s)
- Stella Cellier-Goetghebeur
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Kiana Lafontaine
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Claudèle Lemay-St-Denis
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Princesse Tsamo
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Alexis Bonneau-Burke
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
- Chemistry Department, Université de Montréal, Montréal, QC H2V 0B3, Canada
| | - Janine N. Copp
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Joelle N. Pelletier
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
- Chemistry Department, Université de Montréal, Montréal, QC H2V 0B3, Canada
- Correspondence:
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5
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Mackie ERR, Barrow AS, Christoff RM, Abbott BM, Gendall AR, Soares da Costa TP. A dual-target herbicidal inhibitor of lysine biosynthesis. eLife 2022; 11:78235. [PMID: 35723913 PMCID: PMC9208756 DOI: 10.7554/elife.78235] [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: 03/04/2022] [Accepted: 06/10/2022] [Indexed: 11/29/2022] Open
Abstract
Herbicides with novel modes of action are urgently needed to safeguard global agricultural industries against the damaging effects of herbicide-resistant weeds. We recently developed the first herbicidal inhibitors of lysine biosynthesis, which provided proof-of-concept for a promising novel herbicide target. In this study, we expanded upon our understanding of the mode of action of herbicidal lysine biosynthesis inhibitors. We previously postulated that these inhibitors may act as proherbicides. Here, we show this is not the case. We report an additional mode of action of these inhibitors, through their inhibition of a second lysine biosynthesis enzyme, and investigate the molecular determinants of inhibition. Furthermore, we extend our herbicidal activity analyses to include a weed species of global significance.
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Affiliation(s)
- Emily R R Mackie
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia.,School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Waite Campus, Glen Osmond, Australia
| | - Andrew S Barrow
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Rebecca M Christoff
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Belinda M Abbott
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Anthony R Gendall
- Australian Research Council Industrial Transformation Research Hub for Medicinal Agriculture, AgriBio, La Trobe University, Bundoora, Australia.,Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, Australia
| | - Tatiana P Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia.,School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Waite Campus, Glen Osmond, Australia
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6
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Wang D, Li H, Ma X, Tang Y, Tang H, Huang D, Lin M, Liu Z. Hfq Regulates Efflux Pump Expression and Purine Metabolic Pathway to Increase Trimethoprim Resistance in Aeromonas veronii. Front Microbiol 2021; 12:742114. [PMID: 34899630 PMCID: PMC8652118 DOI: 10.3389/fmicb.2021.742114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/22/2021] [Indexed: 11/29/2022] Open
Abstract
Aeromonas veronii (A. veronii) is a zoonotic pathogen. It causes clinically a variety of diseases such as dysentery, bacteremia, and meningitis, and brings huge losses to aquaculture. A. veronii has been documented as a multiple antibiotic resistant bacterium. Hfq (host factor for RNA bacteriophage Qβ replication) participates in the regulations of the virulence, adhesion, and nitrogen fixation, effecting on the growth, metabolism synthesis and stress resistance in bacteria. The deletion of hfq gene in A. veronii showed more sensitivity to trimethoprim, accompanying by the upregulations of purine metabolic genes and downregulations of efflux pump genes by transcriptomic data analysis. Coherently, the complementation of efflux pump-related genes acrA and acrB recovered the trimethoprim resistance in Δhfq. Besides, the accumulations of adenosine and guanosine were increased in Δhfq in metabonomic data. The strain Δhfq conferred more sensitive to trimethoprim after appending 1 mM guanosine to M9 medium, while wild type was not altered. These results demonstrated that Hfq mediated trimethoprim resistance by elevating efflux pump expression and degrading adenosine, and guanosine metabolites. Collectively, Hfq is a potential target to tackle trimethoprim resistance in A. veronii infection.
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Affiliation(s)
- Dan Wang
- College of Life Sciences, Hainan University, Haikou, China.,College of Tropical Crops Hainan University, Haikou, China
| | - Hong Li
- College of Life Sciences, Hainan University, Haikou, China
| | - Xiang Ma
- College of Life Sciences, Hainan University, Haikou, China
| | - Yanqiong Tang
- College of Life Sciences, Hainan University, Haikou, China
| | - Hongqian Tang
- College of Life Sciences, Hainan University, Haikou, China
| | - Dongyi Huang
- College of Tropical Crops Hainan University, Haikou, China
| | - Min Lin
- Chinese Academy of Agricultural Science, Beijing, China
| | - Zhu Liu
- College of Life Sciences, Hainan University, Haikou, China
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7
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Si L, Gu J, Wen M, Wang R, Fleming J, Li J, Xu J, Bi L, Deng J. relA Inactivation Converts Sulfonamides Into Bactericidal Compounds. Front Microbiol 2021; 12:698468. [PMID: 34646242 PMCID: PMC8503649 DOI: 10.3389/fmicb.2021.698468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
Folates are required for the de novo biosynthesis of purines, thymine, methionine, glycine, and pantothenic acid, key metabolites that bacterial cells cannot survive without. Sulfonamides, which inhibit bacterial folate biosynthesis and are generally considered as bacteriostats, have been extensively used as broad-spectrum antimicrobials for decades. Here we show that, deleting relA in Escherichia coli and other bacterial species converted sulfamethoxazole from a bacteriostat into a bactericide. Not as previously assumed, the bactericidal effect of SMX was not caused by thymine deficiency. When E. coli ∆relA was treated with SMX, reactive oxygen species and ferrous ion accumulated inside the bacterial cells, which caused extensive DNA double-strand breaks without the involvement of incomplete base excision repair. In addition, sulfamethoxazole showed bactericidal effect against E. coli O157 ∆relA in mice, suggesting the possibility of designing new potentiators for sulfonamides targeting RelA. Thus, our study uncovered the previously unknown bactericidal effects of sulfonamides, which advances our understanding of their mechanisms of action, and will facilitate the designing of new potentiators for them.
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Affiliation(s)
- Lizhen Si
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Gu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Mi Wen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruiqi Wang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Joy Fleming
- Key Laboratory of RNA Biology and National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jinyue Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jintian Xu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lijun Bi
- Key Laboratory of RNA Biology and National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- School of Stomatology and Medicine, Foshan University, Foshan, China
- Guangdong Province Key Laboratory of TB Systems Biology and Translational Medicine, Foshan, China
| | - Jiaoyu Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- Guangdong Province Key Laboratory of TB Systems Biology and Translational Medicine, Foshan, China
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8
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Lemay-St-Denis C, Diwan SS, Pelletier JN. The Bacterial Genomic Context of Highly Trimethoprim-Resistant DfrB Dihydrofolate Reductases Highlights an Emerging Threat to Public Health. Antibiotics (Basel) 2021; 10:antibiotics10040433. [PMID: 33924456 PMCID: PMC8103504 DOI: 10.3390/antibiotics10040433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 01/21/2023] Open
Abstract
Type B dihydrofolate reductase (dfrb) genes were identified following the introduction of trimethoprim in the 1960s. Although they intrinsically confer resistance to trimethoprim (TMP) that is orders of magnitude greater than through other mechanisms, the distribution and prevalence of these short (237 bp) genes is unknown. Indeed, this knowledge has been hampered by systematic biases in search methodologies. Here, we investigate the genomic context of dfrbs to gain information on their current distribution in bacterial genomes. Upon searching publicly available databases, we identified 61 sequences containing dfrbs within an analyzable genomic context. The majority (70%) of those sequences also harbor virulence genes and 97% of the dfrbs are found near a mobile genetic element, representing a potential risk for antibiotic resistance genes. We further identified and confirmed the TMP-resistant phenotype of two new members of the family, dfrb10 and dfrb11. Dfrbs are found both in Betaproteobacteria and Gammaproteobacteria, a majority (59%) being in Pseudomonas aeruginosa. Previously labelled as strictly plasmid-borne, we found 69% of dfrbs in the chromosome of pathogenic bacteria. Our results demonstrate that the intrinsically TMP-resistant dfrbs are a potential emerging threat to public health and justify closer surveillance of these genes.
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Affiliation(s)
- Claudèle Lemay-St-Denis
- Department of Biochemistry and Molecular Medecine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Sarah-Slim Diwan
- Department of Biochemistry and Molecular Medecine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
| | - Joelle N Pelletier
- Department of Biochemistry and Molecular Medecine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- PROTEO, The Québec Network for Research on Protein, Function, Engineering and Applications, Québec, QC G1V 0A6, Canada
- CGCC, Center in Green Chemistry and Catalysis, Montréal, QC H3A 0B8, Canada
- Chemistry Department, Université de Montréal, Montréal, QC H2V 0B3, Canada
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