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Shankar G, Akhter Y. Stealing survival: Iron acquisition strategies of Mycobacteriumtuberculosis. Biochimie 2024:S0300-9084(24)00142-1. [PMID: 38901792 DOI: 10.1016/j.biochi.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/07/2024] [Accepted: 06/18/2024] [Indexed: 06/22/2024]
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), faces iron scarcity within the host due to immune defenses. This review explores the importance of iron for Mtb and its strategies to overcome iron restriction. We discuss how the host limits iron as an innate immune response and how Mtb utilizes various iron acquisition systems, particularly the siderophore-mediated pathway. The review illustrates the structure and biosynthesis of mycobactin, a key siderophore in Mtb, and the regulation of its production. We explore the potential of targeting siderophore biosynthesis and uptake as a novel therapeutic approach for TB. Finally, we summarize current knowledge on Mtb's iron acquisition and highlight promising directions for future research to exploit this pathway for developing new TB interventions.
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Affiliation(s)
- Gauri Shankar
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226 025, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226 025, India.
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2
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Cuthbert BJ, Mendoza J, de Miranda R, Papavinasasundaram K, Sassetti CM, Goulding CW. The structure of Mycobacterium thermoresistibile MmpS5 reveals a conserved disulfide bond across mycobacteria. Metallomics 2024; 16:mfae011. [PMID: 38425033 PMCID: PMC10929441 DOI: 10.1093/mtomcs/mfae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/10/2024] [Indexed: 03/02/2024]
Abstract
The tuberculosis (TB) emergency has been a pressing health threat for decades. With the emergence of drug-resistant TB and complications from the COVID-19 pandemic, the TB health crisis is more serious than ever. Mycobacterium tuberculosis (Mtb), the causative agent of TB, requires iron for its survival. Thus, Mtb has evolved several mechanisms to acquire iron from the host. Mtb produces two siderophores, mycobactin and carboxymycobactin, which scavenge for host iron. Mtb siderophore-dependent iron acquisition requires the export of apo-siderophores from the cytosol to the host environment and import of iron-bound siderophores. The export of Mtb apo-siderophores across the inner membrane is facilitated by two mycobacterial inner membrane proteins with their cognate periplasmic accessory proteins, designated MmpL4/MmpS4 and MmpL5/MmpS5. Notably, the Mtb MmpL4/MmpS4 and MmpL5/MmpS5 complexes have also been implicated in the efflux of anti-TB drugs. Herein, we solved the crystal structure of M. thermoresistibile MmpS5. The MmpS5 structure reveals a previously uncharacterized, biologically relevant disulfide bond that appears to be conserved across the Mycobacterium MmpS4/S5 homologs, and comparison with structural homologs suggests that MmpS5 may be dimeric.
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Affiliation(s)
- Bonnie J Cuthbert
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Jessica Mendoza
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Rodger de Miranda
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Kadamba Papavinasasundaram
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Celia W Goulding
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, CA 92697, USA
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA 92697, USA
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3
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Kumar V, Shankar G, Akhter Y. Deciphering drug discovery and microbial pathogenesis research in tuberculosis during the two decades of postgenomic era using entity mining approach. Arch Microbiol 2023; 206:46. [PMID: 38153595 DOI: 10.1007/s00203-023-03776-6] [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: 10/24/2023] [Revised: 11/10/2023] [Accepted: 11/27/2023] [Indexed: 12/29/2023]
Abstract
We examined literature on Mycobacterium tuberculosis (Mtb) subsequent to its genome release, spanning years 1999-2020. We employed scientometric mapping, entity mining, visualization techniques, and PubMed and PubTator databases. Most popular keywords, most active research groups, and growth in quantity of publications were determined. By gathering annotations from the PubTator, we determined direction of research in the areas of drug hypersensitivity, drug resistance (AMR), and drug-related side effects. Additionally, we examined the patterns in research on Mtb metabolism and various forms of tuberculosis, including skin, brain, pulmonary, extrapulmonary, and latent tuberculosis. We discovered that 2011 had the highest annual growth rate of publications, at 19.94%. The USA leads the world in publications with 18,038, followed by China with 14,441, and India with 12,158 publications. Studies on isoniazid and rifampicin resistance showed an enormous increase. Non-tuberculous mycobacteria also been the subject of more research in effort to better understand Mtb physiology and as model organisms. Researchers also looked at co-infections like leprosy, hepatitis, plasmodium, HIV, and other opportunistic infections. Host perspectives like immune response, hypoxia, and reactive oxygen species, as well as comorbidities like arthritis, cancer, diabetes, and kidney disease etc. were also looked at. Symptomatic aspects like fever, coughing, and weight loss were also investigated. Vitamin D has gained popularity as a supplement during illness recovery, however, the interest of researchers declined off late. We delineated dominant researchers, journals, institutions, and leading nations globally, which is crucial for aligning ongoing and evolving landscape of TB research efforts. Recognising the dominant patterns offers important information about the areas of focus for current research, allowing biomedical scientists, clinicians, and organizations to strategically coordinate their efforts with the changing priorities in the field of tuberculosis research.
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Affiliation(s)
- Vinit Kumar
- Department of Library and Information Science, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, 226025, Uttar Pradesh, India.
| | - Gauri Shankar
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, 226025, Uttar Pradesh, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, 226025, Uttar Pradesh, India.
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4
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Williams JT, Baker JJ, Zheng H, Dechow SJ, Fallon J, Murto M, Albrecht VJ, Gilliland HN, Olive AJ, Abramovitch RB. A genetic selection for Mycobacterium smegmatis mutants tolerant to killing by sodium citrate defines a combined role for cation homeostasis and osmotic stress in cell death. mSphere 2023; 8:e0035823. [PMID: 37681985 PMCID: PMC10597346 DOI: 10.1128/msphere.00358-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 07/23/2023] [Indexed: 09/09/2023] Open
Abstract
Mycobacteria can colonize environments where the availability of metal ions is limited. Biological or inorganic chelators play an important role in limiting metal availability, and we developed a model to examine Mycobacterium smegmatis survival in the presence of the chelator sodium citrate. We observed that instead of restricting M. smegmatis growth, concentrated sodium citrate killed M. smegmatis. RNAseq analysis during sodium citrate treatment revealed transcriptional signatures of metal starvation and hyperosmotic stress. Notably, metal starvation and hyperosmotic stress, individually, do not kill M. smegmatis under these conditions. A forward genetic transposon selection was conducted to examine why sodium citrate was lethal, and several sodium-citrate-tolerant mutants were isolated. Based on the identity of three tolerant mutants, mgtE, treZ, and fadD6, we propose a dual stress model of killing by sodium citrate, where sodium citrate chelate metals from the cell envelope and then osmotic stress in combination with a weakened cell envelope causes cell lysis. This sodium citrate tolerance screen identified mutants in several other genes with no known function, with most conserved in the pathogen M. tuberculosis. Therefore, this model will serve as a basis to define their functions, potentially in maintaining cell wall integrity, cation homeostasis, or osmotolerance. IMPORTANCE Bacteria require mechanisms to adapt to environments with differing metal availability. When Mycobacterium smegmatis is treated with high concentrations of the metal chelator sodium citrate, the bacteria are killed. To define the mechanisms underlying killing by sodium citrate, we conducted a genetic selection and observed tolerance to killing in mutants of the mgtE magnesium transporter. Further characterization studies support a model where killing by sodium citrate is driven by a weakened cell wall and osmotic stress, that in combination cause cell lysis.
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Affiliation(s)
- John T. Williams
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Jacob J. Baker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Huiqing Zheng
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Shelby J. Dechow
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Jared Fallon
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Megan Murto
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Veronica J. Albrecht
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Haleigh N. Gilliland
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Andrew J. Olive
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Robert B. Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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Kumar G, Adhikrao PA. Targeting Mycobacterium tuberculosis iron-scavenging tools: a recent update on siderophores inhibitors. RSC Med Chem 2023; 14:1885-1913. [PMID: 37859726 PMCID: PMC10583813 DOI: 10.1039/d3md00201b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 10/21/2023] Open
Abstract
Among the various bacterial infections, tuberculosis (TB) remains a life-threatening infectious disease responsible as the most significant cause of mortality and morbidity worldwide. The co-infection of human immunodeficiency virus (HIV) in association with TB burdens the healthcare system substantially. Notably, M.tb possesses defence against most antitubercular antibiotic drugs, and the efficacy of existing frontline anti-TB drugs is waning. Also, new and recurring cases of TB from resistant bacteria such as multidrug-resistant TB (MDR), extensively drug-resistant TB (XDR), and totally drug-resistant TB (TDR) strains are increasing. Hence, TB begs the scientific community to explore the new therapeutic class of compounds with their novel mechanism. M.tb requires iron from host cells to sustain, grow, and carry out several biological processes. M.tb has developed strategic methods of acquiring iron from the surrounding environment. In this communication, we discuss an overview of M.tb iron-scavenging tools. Also, we have summarized recently identified MbtA and MbtI inhibitors, which prevent M.tb from scavenging iron. These iron-scavenging tool inhibitors have the potential to be developed as anti-TB agents/drugs.
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Affiliation(s)
- Gautam Kumar
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad (NIPER-Hyderabad) Balanagar Hyderabad 500037 India
| | - Patil Amruta Adhikrao
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad (NIPER-Hyderabad) Balanagar Hyderabad 500037 India
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6
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Liu L, Wang W, Wu S, Gao H. Recent Advances in the Siderophore Biology of Shewanella. Front Microbiol 2022; 13:823758. [PMID: 35250939 PMCID: PMC8891985 DOI: 10.3389/fmicb.2022.823758] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/12/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the abundance of iron in nature, iron acquisition is a challenge for life in general because the element mostly exists in the extremely insoluble ferric (Fe3+) form in oxic environments. To overcome this, microbes have evolved multiple iron uptake strategies, a common one of which is through the secretion of siderophores, which are iron-chelating metabolites generated endogenously. Siderophore-mediated iron transport, a standby when default iron transport routes are abolished under iron rich conditions, is essential under iron starvation conditions. While there has been a wealth of knowledge about the molecular basis of siderophore synthesis, uptake and regulation in model bacteria, we still know surprisingly little about siderophore biology in diverse environmental microbes. Shewanella represent a group of γ-proteobacteria capable of respiring a variety of organic and inorganic substrates, including iron ores. This respiratory process relies on a large number of iron proteins, c-type cytochromes in particular. Thus, iron plays an essential and special role in physiology of Shewanella. In addition, these bacteria use a single siderophore biosynthetic system to produce an array of macrocyclic dihydroxamate siderophores, some of which show particular biological activities. In this review, we first outline current understanding of siderophore synthesis, uptake and regulation in model bacteria, and subsequently discuss the siderophore biology in Shewanella.
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Affiliation(s)
- Lulu Liu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wei Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shihua Wu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Haichun Gao
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
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Repurposing Based Identification of Novel Inhibitors against MmpS5-MmpL5 Efflux Pump of Mycobacterium smegmatis: A Combined In Silico and In Vitro Study. Biomedicines 2022; 10:biomedicines10020333. [PMID: 35203542 PMCID: PMC8869396 DOI: 10.3390/biomedicines10020333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 11/17/2022] Open
Abstract
In the current era of a pandemic, infections of COVID-19 and Tuberculosis (TB) enhance the detrimental effects of both diseases in suffering individuals. The resistance mechanisms evolving in Mycobacterium tuberculosis are limiting the efficiency of current therapeutic measures and pressurizing the stressed medical infrastructures. The bacterial efflux pumps enable the development of resistance against recently approved drugs such as bedaquiline and clofazimine. Consequently, the MmpS5-MmpL5 protein system was selected because of its role in efflux pumping of anti-TB drugs. The MmpS5-MmpL5 systems of Mycobacterium smegmatis were modelled and the virtual screening was performed using an ASINEX library of 5968 anti-bacterial compounds. The inhibitors with the highest binding affinities and QSAR based highest predicted inhibitory concentration were selected. The MmpS5-MmpL5 associated systems with BDE_26593610 and BDD_27860195 showed highest inhibitory parameters. These were subjected to 100 ns Molecular Dynamics simulations and provided the validation regarding the interaction studies. The in vitro studies demonstrated that the BDE_26593610 and BDD_27860195 can be considered as active inhibitors for M. smegmatis MmpS5-MmpL5. The outcomes of this study can be utilized in other experimentation aimed at drug design and discovery against the drug resistance strains of M. tuberculosis.
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Mazlan MKN, Mohd Tazizi MHD, Ahmad R, Noh MAA, Bakhtiar A, Wahab HA, Mohd Gazzali A. Antituberculosis Targeted Drug Delivery as a Potential Future Treatment Approach. Antibiotics (Basel) 2021; 10:antibiotics10080908. [PMID: 34438958 PMCID: PMC8388690 DOI: 10.3390/antibiotics10080908] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 01/17/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the microorganism that causes tuberculosis. This infectious disease has been around for centuries, with the earliest record of Mtb around three million years ago. The discovery of the antituberculosis agents in the 20th century has managed to improve the recovery rate and reduce the death rate tremendously. However, the conventional antituberculosis therapy is complicated by the development of resistant strains and adverse drug reactions experienced by the patients. Research has been conducted continuously to discover new, safe, and effective antituberculosis drugs. In the last 50 years, only two molecules were approved despite laborious work and costly research. The repurposing of drugs is also being done with few drugs; antibiotics, particularly, were found to have antituberculosis activity. Besides the discovery work, enhancing the delivery of currently available antituberculosis drugs is also being researched. Targeted drug delivery may be a potentially useful approach to be developed into clinically accepted treatment modalities. Active targeting utilizes a specifically designed targeting agent to deliver a chemically conjugated drug(s) towards Mtb. Passive targeting is very widely explored, with the development of multiple types of nanoparticles from organic and inorganic materials. The nanoparticles will be engulfed by macrophages and this will eliminate the Mtb that is present in the macrophages, or the encapsulated drug may be released at the sites of infections that may be in the form of intra- and extrapulmonary tuberculosis. This article provided an overview on the history of tuberculosis and the currently available treatment options, followed by discussions on the discovery of new antituberculosis drugs and active and passive targeting approaches against Mycobacterium tuberculosis.
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Affiliation(s)
- Mohd Khairul Nizam Mazlan
- CHEST, School of Pharmaceutical Sciences, Sains@USM, Universiti Sains Malaysia, Bayan Lepas 11900, Malaysia; (M.K.N.M.); (R.A.)
| | | | - Rosliza Ahmad
- CHEST, School of Pharmaceutical Sciences, Sains@USM, Universiti Sains Malaysia, Bayan Lepas 11900, Malaysia; (M.K.N.M.); (R.A.)
| | - Muhammad Amirul Asyraf Noh
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia; (M.H.D.M.T.); (M.A.A.N.)
| | - Athirah Bakhtiar
- School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Malaysia;
| | - Habibah A. Wahab
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia; (M.H.D.M.T.); (M.A.A.N.)
- Correspondence: (H.A.W.); (A.M.G.)
| | - Amirah Mohd Gazzali
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia; (M.H.D.M.T.); (M.A.A.N.)
- Correspondence: (H.A.W.); (A.M.G.)
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9
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Laws M, Jin P, Rahman KM. Efflux pumps in Mycobacterium tuberculosis and their inhibition to tackle antimicrobial resistance. Trends Microbiol 2021; 30:57-68. [PMID: 34052094 DOI: 10.1016/j.tim.2021.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 02/08/2023]
Abstract
Tuberculosis (TB), an infectious disease caused by the bacterium Mycobacterium tuberculosis, was the leading cause of mortality worldwide in 2019 due to a single infectious agent. The growing threat of strains of M. tuberculosis untreatable by modern antibiotic regimens only exacerbates this problem. In response to this continued public health emergency, research into methods of potentiating currently approved antimicrobial agents against resistant strains of M. tuberculosis is an urgent priority, and a key strategy in this regard is the design of mycobacterial efflux pump inhibitors (EPIs). This review summarises the current state of knowledge surrounding drug-related efflux pumps in M. tuberculosis and presents recent updates within the field of mycobacterial EPIs with a view to aiding the design of an effective adjunct therapy to overcome efflux-mediated resistance in TB.
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Affiliation(s)
- Mark Laws
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Peiqin Jin
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Khondaker Miraz Rahman
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
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10
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Klenotic PA, Moseng MA, Morgan CE, Yu EW. Structural and Functional Diversity of Resistance-Nodulation-Cell Division Transporters. Chem Rev 2021; 121:5378-5416. [PMID: 33211490 PMCID: PMC8119314 DOI: 10.1021/acs.chemrev.0c00621] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Multidrug resistant (MDR) bacteria are a global threat with many common infections becoming increasingly difficult to eliminate. While significant effort has gone into the development of potent biocides, the effectiveness of many first-line antibiotics has been diminished due to adaptive resistance mechanisms. Bacterial membrane proteins belonging to the resistance-nodulation-cell division (RND) superfamily play significant roles in mediating bacterial resistance to antimicrobials. They participate in multidrug efflux and cell wall biogenesis to transform bacterial pathogens into "superbugs" that are resistant even to last resort antibiotics. In this review, we summarize the RND superfamily of efflux transporters with a primary focus on the assembly and function of the inner membrane pumps. These pumps are critical for extrusion of antibiotics from the cell as well as the transport of lipid moieties to the outer membrane to establish membrane rigidity and stability. We analyze recently solved structures of bacterial inner membrane efflux pumps as to how they bind and transport their substrates. Our cumulative data indicate that these RND membrane proteins are able to utilize different oligomerization states to achieve particular activities, including forming MDR pumps and cell wall remodeling machineries, to ensure bacterial survival. This mechanistic insight, combined with simulated docking techniques, allows for the design and optimization of new efflux pump inhibitors to more effectively treat infections that today are difficult or impossible to cure.
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Affiliation(s)
- Philip A. Klenotic
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Mitchell A. Moseng
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Christopher E. Morgan
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
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11
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Henderson PJF, Maher C, Elbourne LDH, Eijkelkamp BA, Paulsen IT, Hassan KA. Physiological Functions of Bacterial "Multidrug" Efflux Pumps. Chem Rev 2021; 121:5417-5478. [PMID: 33761243 DOI: 10.1021/acs.chemrev.0c01226] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial multidrug efflux pumps have come to prominence in human and veterinary pathogenesis because they help bacteria protect themselves against the antimicrobials used to overcome their infections. However, it is increasingly realized that many, probably most, such pumps have physiological roles that are distinct from protection of bacteria against antimicrobials administered by humans. Here we undertake a broad survey of the proteins involved, allied to detailed examples of their evolution, energetics, structures, chemical recognition, and molecular mechanisms, together with the experimental strategies that enable rapid and economical progress in understanding their true physiological roles. Once these roles are established, the knowledge can be harnessed to design more effective drugs, improve existing microbial production of drugs for clinical practice and of feedstocks for commercial exploitation, and even develop more sustainable biological processes that avoid, for example, utilization of petroleum.
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Affiliation(s)
- Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Claire Maher
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia
| | - Liam D H Elbourne
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Ian T Paulsen
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
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12
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Resistance against Membrane-Inserting MmpL3 Inhibitor through Upregulation of MmpL5 in Mycobacterium tuberculosis. Antimicrob Agents Chemother 2020; 64:AAC.01100-20. [PMID: 32958714 PMCID: PMC7674061 DOI: 10.1128/aac.01100-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/16/2020] [Indexed: 11/28/2022] Open
Abstract
Spiroketal indolyl Mannich bases (SIMBs) present a novel class of membrane-inserting antimycobacterials with efficacy in a tuberculosis mouse model. SIMBs exert their antibacterial activity by two mechanisms. The indolyl Mannich base scaffold causes permeabilization of bacteria, and the spiroketal moiety contributes to inhibition of the mycolic acid transporter MmpL3. Here, we show that low-level resistance to SIMBs arises by mutations in the transcriptional repressor MmpR5, resulting in upregulation of the efflux pump MmpL5. Spiroketal indolyl Mannich bases (SIMBs) present a novel class of membrane-inserting antimycobacterials with efficacy in a tuberculosis mouse model. SIMBs exert their antibacterial activity by two mechanisms. The indolyl Mannich base scaffold causes permeabilization of bacteria, and the spiroketal moiety contributes to inhibition of the mycolic acid transporter MmpL3. Here, we show that low-level resistance to SIMBs arises by mutations in the transcriptional repressor MmpR5, resulting in upregulation of the efflux pump MmpL5.
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13
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Maslov DA, Shur KV, Vatlin AA, Danilenko VN. MmpS5-MmpL5 Transporters Provide Mycobacterium smegmatis Resistance to imidazo[1,2- b][1,2,4,5]tetrazines. Pathogens 2020; 9:E166. [PMID: 32121069 PMCID: PMC7157563 DOI: 10.3390/pathogens9030166] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/19/2020] [Accepted: 02/25/2020] [Indexed: 12/18/2022] Open
Abstract
The emergence and spread of drug-resistant Mycobacterium tuberculosis strains (including MDR, XDR, and TDR) force scientists worldwide to search for new anti-tuberculosis drugs. We have previously reported a number of imidazo[1,2-b][1,2,4,5]tetrazines - putative inhibitors of mycobacterial eukaryotic-type serine-threonine protein-kinases, active against M. tuberculosis. Whole genomic sequences of spontaneous drug-resistant M. smegmatis mutants revealed four genes possibly involved in imidazo[1,2-b][1,2,4,5]tetrazines resistance; however, the exact mechanism of resistance remain unknown. We used different approaches (construction of targeted mutants, overexpression of the wild-type (w.t.) and mutant genes, and gene-expression studies) to assess the role of the previously identified mutations. We show that mutations in MSMEG_1380 gene lead to overexpression of the mmpS5-mmpL5 operon in M. smegmatis, thus providing resistance to imidazo[1,2-b][1,2,4,5]tetrazines by increased efflux through the MmpS5-MmpL5 system, similarly to the mechanisms of resistance described for M. tuberculosis and M. abscessus. Mycobacterial MmpS5-MmpL5 transporters should be considered as an MDR-efflux system and they should be taken into account at early stages of anti-tuberculosis drug development.
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Affiliation(s)
- Dmitry A. Maslov
- Laboratory of Bacterial Genetics, Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow 119333, Russia; (K.V.S.); (A.A.V.); (V.N.D.)
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14
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Protein-protein complexes as targets for drug discovery against infectious diseases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 121:237-251. [PMID: 32312423 DOI: 10.1016/bs.apcsb.2019.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Antibiotics are therapeutic agents against bacterial infections, however, the emergence of multiple and extremely drug-resistant microbes (Multi-Drug Resistant and Extremely Drug-Resistant) are compromising the effectiveness of the currently available treatment options. The drug resistance is not a novel crisis, the current pace of drug discovery has failed to compete with the growth of MDR and XDR pathogenic strains and therefore, it is highly central to find out novel antimicrobial drugs with unique mechanisms of action which may reduce the burden of MDR and XDR pathogenic strains. Protein-protein interactions (PPIs) are involved in a countless of the physiological and cellular phenomena and have become an attractive target to treat the diseases. Therefore, targeting PPIs in infectious agents may offer a completely novel strategy of intervention to develop anti-infective drugs that may combat the ever-increasing rate of drug resistant strains. This chapter describes how small molecule candidate inhibitors that are capable of disrupting the PPIs in pathogenic microbes and it could be an alternative lead discovery strategy to obtain novel antibiotics. Over the last three decades, there has been increasing efforts focused on the manipulation of PPIs in order to develop novel therapeutic interventions. The diversity and complexity of such a complex and highly dynamic systems pose many challenges in targeting PPIs by drug-like molecules with necessary selectivity and potency. Traditional and novel drug discovery strategies have provided tools for designing and assessing PPI inhibitors against infectious diseases.
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Melly GC, Stokas H, Dunaj JL, Hsu FF, Rajavel M, Su CC, Yu EW, Purdy GE. Structural and functional evidence that lipoprotein LpqN supports cell envelope biogenesis in Mycobacterium tuberculosis. J Biol Chem 2019; 294:15711-15723. [PMID: 31471317 PMCID: PMC6816100 DOI: 10.1074/jbc.ra119.008781] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 08/27/2019] [Indexed: 01/07/2023] Open
Abstract
The mycobacterial cell envelope is crucial to host-pathogen interactions as a barrier against antibiotics and the host immune response. In addition, cell envelope lipids are mycobacterial virulence factors. Cell envelope lipid biosynthesis is the target of a number of frontline tuberculosis treatments and has been the focus of much research. However, the transport mechanisms by which these lipids reach the mycomembrane remain poorly understood. Many envelope lipids are exported from the cytoplasm to the periplasmic space via the mycobacterial membrane protein large (MmpL) family of proteins. In other bacteria, lipoproteins can contribute to outer membrane biogenesis through direct binding of substrates and/or protein-protein associations with extracytoplasmic biosynthetic enzymes. In this report, we investigate whether the lipoprotein LpqN plays a similar role in mycobacteria. Using a genetic two-hybrid approach, we demonstrate that LpqN interacts with periplasmic loop domains of the MmpL3 and MmpL11 transporters that export mycolic acid-containing cell envelope lipids. We observe that LpqN also interacts with secreted cell envelope biosynthetic enzymes such as Ag85A via pulldown assays. The X-ray crystal structures of LpqN and LpqN bound to dodecyl-trehalose suggest that LpqN directly binds trehalose monomycolate, the MmpL3 and Ag85A substrate. Finally, we observe altered lipid profiles of the ΔlpqN mutant during biofilm maturation, pointing toward a possible physiological role for the protein. The results of this study suggest that LpqN may act as a membrane fusion protein, connecting MmpL transporters with periplasmic proteins, and provide general insight into the role of lipoproteins in Mycobacterium tuberculosis cell envelope biogenesis.
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Affiliation(s)
- Geoff C. Melly
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239
| | - Haley Stokas
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239
| | - Jennifer L. Dunaj
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239
| | - Fong Fu Hsu
- Department of Internal Medicine, Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri 63110
| | | | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Georgiana E. Purdy
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239, To whom correspondence should be addressed. Tel.:
503-346-0767; E-mail:
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16
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Melly G, Purdy GE. MmpL Proteins in Physiology and Pathogenesis of M. tuberculosis. Microorganisms 2019; 7:microorganisms7030070. [PMID: 30841535 PMCID: PMC6463170 DOI: 10.3390/microorganisms7030070] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/14/2019] [Accepted: 03/03/2019] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) remains an important human pathogen. The Mtb cell envelope is a critical bacterial structure that contributes to virulence and pathogenicity. Mycobacterial membrane protein large (MmpL) proteins export bulky, hydrophobic substrates that are essential for the unique structure of the cell envelope and directly support the ability of Mtb to infect and persist in the host. This review summarizes recent investigations that have enabled insight into the molecular mechanisms underlying MmpL substrate export and the role that these substrates play during Mtb infection.
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Affiliation(s)
- Geoff Melly
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Georgiana E Purdy
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
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17
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Briffotaux J, Huang W, Wang X, Gicquel B. MmpS5/MmpL5 as an efflux pump in Mycobacterium species. Tuberculosis (Edinb) 2017; 107:13-19. [DOI: 10.1016/j.tube.2017.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 10/19/2022]
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18
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Dhusia K, Bajpai A, Ramteke PW. Overcoming antibiotic resistance: Is siderophore Trojan horse conjugation an answer to evolving resistance in microbial pathogens? J Control Release 2017; 269:63-87. [PMID: 29129658 DOI: 10.1016/j.jconrel.2017.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 01/11/2023]
Abstract
Comparative study of siderophore biosynthesis pathway in pathogens provides potential targets for antibiotics and host drug delivery as a part of computationally feasible microbial therapy. Iron acquisition using siderophore models is an essential and well established model in all microorganisms and microbial infections a known to cause great havoc to both plant and animal. Rapid development of antibiotic resistance in bacterial as well as fungal pathogens has drawn us at a verge where one has to get rid of the traditional way of obstructing pathogen using single or multiple antibiotic/chemical inhibitors or drugs. 'Trojan horse' strategy is an answer to this imperative call where antibiotic are by far sneaked into the pathogenic cell via the siderophore receptors at cell and outer membrane. This antibiotic once gets inside, generates a 'black hole' scenario within the opportunistic pathogens via iron scarcity. For pathogens whose siderophore are not compatible to smuggle drug due to their complex conformation and stiff valence bonds, there is another approach. By means of the siderophore biosynthesis pathways, potential targets for inhibition of these siderophores in pathogenic bacteria could be achieved and thus control pathogenic virulence. Method to design artificial exogenous siderophores for pathogens that would compete and succeed the battle of intake is also covered with this review. These manipulated siderophore would enter pathogenic cell like any other siderophore but will not disperse iron due to which iron inadequacy and hence pathogens control be accomplished. The aim of this review is to offer strategies to overcome the microbial infections/pathogens using siderophore.
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Affiliation(s)
- Kalyani Dhusia
- Deptartment of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bio-Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Allahabad-211007 (U.P.), India
| | - Archana Bajpai
- Laboratory for Disease Systems Modeling, Center for Integrative Medical Sciences, RIKEN, Yokohama City, Kanagawa, 230-0045, Japan
| | - P W Ramteke
- Deptartment of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bio-Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Allahabad-211007 (U.P.), India
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Sandhu P, Akhter Y. Evolution of structural fitness and multifunctional aspects of mycobacterial RND family transporters. Arch Microbiol 2017; 200:19-31. [PMID: 28951954 DOI: 10.1007/s00203-017-1434-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/07/2017] [Accepted: 09/20/2017] [Indexed: 12/11/2022]
Abstract
Drug resistance is a major concern due to the evolution and emergence of pathogenic bacterial strains with novel strategies to resist the antibiotics in use. Mycobacterium tuberculosis (Mtb) is one of such pathogens with reported strains, which are not treatable with any of the available anti-TB drugs. This scenario has led to the need to look for some novel drug targets in Mtb, which may be exploited to design effective treatment strategies against the infection. The goal of this review is to discuss one such class of emerging drug targets in Mtb. MmpL (mycobacterial membrane protein large) proteins from Mtb are reported to be involved in multi-substrate transport including drug efflux and considered as one of the contributing factors for the emergence of multidrug-resistant strains. MmpL proteins belong to resistance nodulation division permeases superfamily of membrane transporters, which are viably and pathogenetically important and their inhibition could be lethal for the bacteria.
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Affiliation(s)
- Padmani Sandhu
- Structural Bioinformatics Group, Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Shahpur District, Kangra, Himachal Pradesh, 176206, India
| | - Yusuf Akhter
- Structural Bioinformatics Group, Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Shahpur District, Kangra, Himachal Pradesh, 176206, India.
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20
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Akhter Y, Thakur S. Targets of ubiquitin like system in mycobacteria and related actinobacterial species. Microbiol Res 2017; 204:9-29. [PMID: 28870295 DOI: 10.1016/j.micres.2017.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/22/2017] [Accepted: 07/05/2017] [Indexed: 12/22/2022]
Abstract
Protein turnover and recycling is a prerequisite in all living organisms to maintain normal cellular physiology. Many bacteria are proteasome deficient but they possess typical protease enzymes for carrying out protein turnover. However, several groups of actinobacteria such as mycobacteria harbor both proteasome and proteases. In these bacteria, for cellular protein turnover the target proteins undergo post-translational modification referred as pupylation in which a small protein Pup (prokaryotic ubiquitin-like protein) is tagged to the specific lysine residues of the target proteins and after that those target proteins undergo proteasomal degradation. Thus, Pup serves as a degradation signal, helps in directing proteins toward the bacterial proteasome for a turnover. Although the Pup-proteasome system has a multifaceted role in environmental stresses, pathogenicity and regulation of cellular signaling, but the fate of all types of pupylation such as mono and polypupylation on the proteins is still not completely understood. In this review, we present the mechanisms involved in the activation and conjugation of Pup to the target proteins, describing the structural sketch of pupylation and fundamental differences between the eukaryotic ubiquitin-proteasome and bacterial Pup-proteasome systems. We are also presenting a concise classification and cataloging of the complete battery of experimentally identified Pup-substrates from various species of actinobacteria.
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Affiliation(s)
- Yusuf Akhter
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh, 176206, India.
| | - Shweta Thakur
- School of Life Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh, 176206, India
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