scholarly journals Crystal Structure of Mycobacterium tuberculosis Elongation Factor G1

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaopan Gao ◽  
Xia Yu ◽  
Kaixiang Zhu ◽  
Bo Qin ◽  
Wei Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
Drug Target ◽  
Drug Targets ◽  
Elongation Factor ◽  
Protein Translation ◽  
Crystal Form ◽  
Multidrug Resistant ◽  
Major Focus ◽  
Trna Translocation

Mycobacterium tuberculosis (Mtb) caused an estimated 10 million cases of tuberculosis and 1.2 million deaths in 2019 globally. The increasing emergence of multidrug-resistant and extensively drug-resistant Mtb is becoming a public health threat worldwide and makes the identification of anti-Mtb drug targets urgent. Elongation factor G (EF-G) is involved in tRNA translocation on ribosomes during protein translation. Therefore, EF-G is a major focus of structural analysis and a valuable drug target of antibiotics. However, the crystal structure of Mtb EF-G1 is not yet available, and this has limited the design of inhibitors. Here, we report the crystal structure of Mtb EF-G1 in complex with GDP. The unique crystal form of the Mtb EF-G1-GDP complex provides an excellent platform for fragment-based screening using a crystallographic approach. Our findings provide a structure-based explanation for GDP recognition, and facilitate the identification of EF-G1 inhibitors with potential interest in the context of drug discovery.

scholarly journals Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 607
Author(s):  
Nadeem Ullah ◽  
Ling Hao ◽  
Jo-Lewis Banga Ndzouboukou ◽  
Shiyun Chen ◽  
Yaqi Wu ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Control Strategies ◽  
Multidrug Resistant ◽  
Differentially Expressed ◽  
Effective Control ◽  
Drug Resistant ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Candidate Target

Rifampicin (RIF) is one of the most important first-line anti-tuberculosis (TB) drugs, and more than 90% of RIF-resistant (RR) Mycobacterium tuberculosis clinical isolates belong to multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. In order to identify specific candidate target proteins as diagnostic markers or drug targets, differential protein expression between drug-sensitive (DS) and drug-resistant (DR) strains remains to be investigated. In the present study, a label-free, quantitative proteomics technique was performed to compare the proteome of DS, RR, MDR, and XDR clinical strains. We found iniC, Rv2141c, folB, and Rv2561 were up-regulated in both RR and MDR strains, while fadE9, espB, espL, esxK, and Rv3175 were down-regulated in the three DR strains when compared to the DS strain. In addition, lprF, mce2R, mce2B, and Rv2627c were specifically expressed in the three DR strains, and 41 proteins were not detected in the DS strain. Functional category showed that these differentially expressed proteins were mainly involved in the cell wall and cell processes. When compared to the RR strain, Rv2272, smtB, lpqB, icd1, and folK were up-regulated, while esxK, PPE19, Rv1534, rpmI, ureA, tpx, mpt64, frr, Rv3678c, esxB, esxA, and espL were down-regulated in both MDR and XDR strains. Additionally, nrp, PPE3, mntH, Rv1188, Rv1473, nadB, PPE36, and sseA were specifically expressed in both MDR and XDR strains, whereas 292 proteins were not identified when compared to the RR strain. When compared between MDR and XDR strains, 52 proteins were up-regulated, while 45 proteins were down-regulated in the XDR strain. 316 proteins were especially expressed in the XDR strain, while 92 proteins were especially detected in the MDR strain. Protein interaction networks further revealed the mechanism of their involvement in virulence and drug resistance. Therefore, these differentially expressed proteins are of great significance for exploring effective control strategies of DR-TB.

scholarly journals Molecular Investigation of Resistance to the Antituberculous Drug Ethionamide in Multidrug-Resistant Clinical Isolates ofMycobacterium tuberculosis

2010 ◽  
Vol 55 (1) ◽  
pp. 355-360 ◽  
Author(s):  
F. Brossier ◽  
N. Veziris ◽  
C. Truffot-Pernot ◽  
V. Jarlier ◽  
W. Sougakoff
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Nadh Dehydrogenase ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Cell Wall Biosynthesis ◽  
Molecular Investigation ◽  
Antituberculous Drug ◽  
Resistant Cells

ABSTRACTEthionamide (ETH) needs to be activated by the mono-oxygenase EthA, which is regulated by EthR, in order to be active againstMycobacterium tuberculosis. The activated drug targets the enzyme InhA, which is involved in cell wall biosynthesis. Resistance to ETH has been reported to result from various mechanisms, including mutations altering EthA/EthR, InhA and its promoter, the NADH dehydrogenase encoded byndh, and the MshA enzyme, involved in mycothiol biosynthesis. We searched for such mutations in 87 clinical isolates: 47 ETH-resistant (ETHr) isolates, 24 ETH-susceptible (ETHs) isolates, and 16 isolates susceptible to ETH but displaying an intermediate proportion of resistant cells (ETHSip; defined as ≥1% but <10% resistant cells). In 81% (38/47) of the ETHrisolates, we found mutations inethA,ethR, orinhAor its promoter, which mostly corresponded to new alterations inethAandethR. The 9 ETHrisolates without a mutation in these three genes (9/47, 19%) had no mutation inndh, and a single isolate had a mutation inmshA. Of the 16 ETHSipisolates, 7 had a mutation inethA, 8 had no detectable mutation, and 1 had a mutation inmshA. Finally, of the 24 ETHsisolates, 23 had no mutation in the studied genes and 1 displayed a yet unknown mutation in theinhApromoter. Globally, the mechanism of resistance to ETH remained unknown for 19% of the ETHrisolates, highlighting the complexity of the mechanisms of ETH resistance inM. tuberculosis.

In Silico Drug Target Discovery Through Proteome Mining from M. tuberculosis: An Insight into Antivirulent Therapy

2020 ◽  
Vol 23 (3) ◽  
pp. 253-268
Author(s):  
Shreya Bhattacharya ◽  
Puja Ghosh ◽  
Debasmita Banerjee ◽  
Arundhati Banerjee ◽  
Sujay Ray
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Virulence Factors ◽  
Spectrum Analysis ◽  
Drug Target ◽  
Drug Targets ◽  
Physicochemical Characterization ◽  
Specific Drug ◽  
Hypothetical Proteins ◽  
Drug Target Discovery ◽  
Domain Annotation

Aim and Objective: One of the challenges to conventional therapies against Mycobacterium tuberculosis is the development of multi-drug resistant pathogenic strains. This study was undertaken to explore new therapeutic targets for the revolutionary antivirulence therapy utilizing the pathogen’s essential hypothetical proteins, serving as virulence factors, which is the essential first step in novel drug designing. Methods: Functional annotations of essential hypothetical proteins from Mycobacterium tuberculosis (H37Rv strain) were performed through domain annotation, Gene Ontology analysis, physicochemical characterization and prediction of subcellular localization. Virulence factors among the essential hypothetical proteins were predicted, among which pathogen-specific drug target candidates, non-homologous to human and gut microbiota, were identified. This was followed by druggability and spectrum analysis of the identified targets. Results and conclusion: The study successfully assigned functions of 83 essential hypothetical proteins of Mycobacterium tuberculosis, among which 25 were identified as virulence factors. Out of 25, 12 virulence factors were observed as potential pathogen-specific drug target candidates. Nine potential targets had druggable properties and rest three were considered as novel targets. Exploration of these targets will provide new insights into future drug development. Characterization of subcellular localizations revealed that most of the predicted targets were cytoplasmic which could be ideal for intracellular drugs, while two drug targets were membranebound, ideal for vaccines. Spectrum analysis identified one broad-spectrum and 11 narrowspectrum targets. This study would, therefore, instigate designing novel therapeutics for antivirulence therapy, which have the potential to serve as revolutionary treatment instead of conventional antibiotic therapies to overcome the lethality of antibiotic-resistant strains.

scholarly journals Functional Characterization by Genetic Complementation of aroB-Encoded Dehydroquinate Synthase from Mycobacterium tuberculosis H37Rv and Its Heterologous Expression and Purification

2007 ◽  
Vol 189 (17) ◽  
pp. 6246-6252 ◽  
Author(s):  
Jordana Dutra de Mendonça ◽  
Fernanda Ely ◽  
Mario Sergio Palma ◽  
Jeverson Frazzon ◽  
Luiz Augusto Basso ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Rational Design ◽  
Functional Characterization ◽  
Pcr Amplification ◽  
Shikimate Pathway ◽  
Aromatic Amino Acids ◽  
Multidrug Resistant ◽  
Genetic Complementation ◽  
Dehydroquinate Synthase

ABSTRACT The recent recrudescence of Mycobacterium tuberculosis infection and the emergence of multidrug-resistant strains have created an urgent need for new therapeutics against tuberculosis. The enzymes of the shikimate pathway are attractive drug targets because this route is absent in mammals and, in M. tuberculosis, it is essential for pathogen viability. This pathway leads to the biosynthesis of aromatic compounds, including aromatic amino acids, and it is found in plants, fungi, bacteria, and apicomplexan parasites. The aroB-encoded enzyme dehydroquinate synthase is the second enzyme of this pathway, and it catalyzes the cyclization of 3-deoxy-d-arabino-heptulosonate-7-phosphate in 3-dehydroquinate. Here we describe the PCR amplification and cloning of the aroB gene and the overexpression and purification of its product, dehydroquinate synthase, to homogeneity. In order to probe where the recombinant dehydroquinate synthase was active, genetic complementation studies were performed. The Escherichia coli AB2847 mutant was used to demonstrate that the plasmid construction was able to repair the mutants, allowing them to grow in minimal medium devoid of aromatic compound supplementation. In addition, homogeneous recombinant M. tuberculosis dehydroquinate synthase was active in the absence of other enzymes, showing that it is homomeric. These results will support the structural studies with M. tuberculosis dehydroquinate synthase that are essential for the rational design of antimycobacterial agents.

scholarly journals Secretory Proteome Analysis of Streptomycin-Resistant Mycobacterium tuberculosis Clinical Isolates

2017 ◽  
Vol 22 (10) ◽  
pp. 1229-1238 ◽  
Author(s):  
Divakar Sharma ◽  
Deepa Bisht
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Cumulative Effect ◽  
Proteome Analysis ◽  
Multidrug Resistant ◽  
Diagnostic Markers ◽  
Resistant Isolate ◽  
Secretory Proteins ◽  
Bioinformatic Tools ◽  
Flight Mass Spectrometry

Tuberculosis still remains one of the most fatal infectious diseases. Streptomycin (SM) is the drug of choice, especially for patients with multidrug-resistant tuberculosis or category II patients, because it targets the protein synthesis machinery by interacting with steps of translation. Several mechanisms have been proposed to explain the resistance, but our knowledge is inadequate. Secretome often plays an important role in pathogenesis and is considered an attractive reservoir for the development of novel diagnostic markers and targets. In this study, we analyze the secretory proteins of streptomycin-resistant Mycobacterium tuberculosis isolates by 2-dimensional gel electrophoresis–matrix assisted laser desorption/ionization–time-of-flight mass spectrometry and bioinformatic tools. Fifteen overexpressed proteins were identified in a resistant isolate that belonged to various categories such as virulence/detoxification/adaptation, intermediary metabolism and respiration, and conserved hypotheticals. Among them, Rv1860, Rv1980c, Rv2140c, Rv1636, and Rv1926c were proteins of an undefined role. Molecular docking of these proteins with SM showed that it binds to their conserved domains and suggests that these might neutralize/compensate the effect of the drug. The interactome also suggests that overexpressed proteins along with their interactive partner might be involved in M. tuberculosis virulence and resistance. The cumulative effect of these overexpressed proteins could involve SM resistance, and these might be used as diagnostic markers or potential drug targets.

Comparative Proteome Analysis of Mycobacterium Tuberculosis Strains - H37Ra, H37Rv, CCDC5180, and CAS/NITR204: A Step Forward to Identify Novel Drug Targets

2020 ◽  
Vol 17 (11) ◽  
pp. 1422-1431
Author(s):  
Shradheya R.R. Gupta ◽  
Ekta Gupta ◽  
Avnam Ohri ◽  
Sandeep Kumar Shrivastava ◽  
Sumita Kachhwaha ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Target ◽  
Drug Targets ◽  
Virulent Strain ◽  
Proteome Analysis ◽  
Target Protein ◽  
Central Asian ◽  
Virulent Strains ◽  
Novel Drug ◽  
Novel Drug Targets

Background: Mycobacterium tuberculosis is a causative agent of tuberculosis. It is a non-motile, acid-fast, obligatory aerobic bacterium. Finding novel drug targets in Mycobacterium tuberculosis has become extremely important as the bacterium is evolving into a more dangerous multi-drug resistant pathogen. The predominant strains in India belong to the Central-Asian, East- African Indian, and Beijing clad. For the same reason, the whole proteomes of a non-virulent strain (H37Ra), a virulent (H37Rv) and two clinical strains, a Central-Asian clad (CAS/NITR204) and a Beijing clad (CCDC5180) have been selected for comparative study. Selecting a phylogenetically close and majorly studied non-virulent strain is helpful in removing the common and undesired proteins from the study. Objective: The study compares the whole proteome of non-virulent strain with the other three virulent strains to find a unique protein responsible for virulence in virulent strains. It is expected that the drugs developed against identified targets will be specific to the virulent strains. Additionally, to assure minimal toxicity to the host, we also screened the human proteome. Methods: Comparative proteome analysis was used for target identification and in silico validation of identified target protein Rv2466c, identification of the respective ligand of the identified target protein and binding interaction study using Molecular docking and Molecular Dynamic Simulation study were used in this study. Results and Discussion: Finally, eleven proteins were found to be unique in virulent strain only and out of which, Rv2466c (PDB-ID: 4ZIL) was found to be an essential protein and identified as a putative drug target protein for further study. The compound glutathione was found to be a suitable inhibitor for Rv2466c. In this study, we used a comparative proteomics approach to identify novel target proteins. Conclusion: This study is unique as we are assured that the study will move forward the research in a new direction to cure the deadly disease (tuberculosis) caused by Mycobacterium tuberculosis. Rv2466c was identified as a novel drug target and glutathione as a respective ligand of Rv2466c. Discovery of the novel drug target as well as the drug will provide a solution to drug resistance as well as the infection caused by Mycobacterium tuberculosis.

scholarly journals Comparative Genome and Network Centrality Analysis to Identify Drug Targets ofMycobacterium tuberculosis H37Rv

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tilahun Melak ◽  
Sunita Gakkhar
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Target ◽  
Drug Targets ◽  
Tuberculosis H37rv ◽  
Network Centrality ◽  
Potential Drug ◽  
Comparative Genome ◽  
Mycobacterium Tuberculosis H37rv ◽  
Centrality Analysis ◽  
Potential Drug Targets

Potential drug targets ofMycobacterium tuberculosis H37Rvwere identified through systematically integrated comparative genome and network centrality analysis. The comparative analysis of the complete genome ofMycobacterium tuberculosis H37Rvagainst Database of Essential Genes (DEG) yields a list of proteins which are essential for the growth and survival of the pathogen. Those proteins which are nonhomologous with human were selected. The resulting proteins were then prioritized by using the four network centrality measures: degree, closeness, betweenness, and eigenvector. Proteins whose centrality value is close to the centre of gravity of the interactome network were proposed as a final list of potential drug targets for the pathogen. The use of an integrated approach is believed to increase the success of the drug target identification process. For the purpose of validation, selective comparisons have been made among the proposed targets and previously identified drug targets by various other methods. About half of these proteins have been already reported as potential drug targets. We believe that the identified proteins will be an important input to experimental study which in the way could save considerable amount of time and cost of drug target discovery.

scholarly journals Novel Saccharomyces cerevisiae Screen Identifies WR99210 Analogues That Inhibit Mycobacterium tuberculosis Dihydrofolate Reductase

2002 ◽  
Vol 46 (11) ◽  
pp. 3362-3369 ◽  
Author(s):  
A'Lissa B. Gerum ◽  
Jonathan E. Ulmer ◽  
David P. Jacobus ◽  
Norman P. Jensen ◽  
David R. Sherman ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mycobacterium Tuberculosis ◽  
Dihydrofolate Reductase ◽  
Drug Target ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Treatment Regimens ◽  
Key Enzyme ◽  
Level 3

ABSTRACT The ongoing selection of multidrug-resistant strains of Mycobacterium tuberculosis has markedly reduced the effectiveness of the standard treatment regimens. Thus, there is an urgent need for new drugs that are potent inhibitors of M. tuberculosis, that exhibit favorable resistance profiles, and that are well tolerated by patients. One promising drug target for treatment of mycobacterial infections is dihydrofolate reductase (DHFR; EC 1.5.1.3), a key enzyme in folate utilization. DHFR is an important drug target in many pathogens, but it has not been exploited in the search for drugs effective against M. tuberculosis. The triazine DHFR inhibitor WR99210 has been shown to be effective against other mycobacteria. We show here that WR99210 is also a potent inhibitor of M. tuberculosis and Mycobacterium bovis BCG growth in vitro and that resistance to WR99210 occurred less frequently than resistance to either rifampin or isoniazid. Screening of drugs with M. tuberculosis cultures is slow and requires biosafety level 3 facilities and procedures. We have developed an alternative strategy: initial screening in an engineered strain of the budding yeast Saccharomyces cerevisiae that is dependent on the M. tuberculosis DHFR for its growth. Using this system, we have screened 19 compounds related to WR99210 and found that 7 of these related compounds are also potent inhibitors of the M. tuberculosis DHFR. These studies suggest that compounds of this class are excellent potential leads for further development of drugs effective against M. tuberculosis.

scholarly journals Identification of Missing Carbon Fixation Enzymes as Potential Drug Targets in Mycobacterium Tuberculosis

2018 ◽  
Vol 15 (3) ◽  
Author(s):  
Amit Katiyar ◽  
Harpreet Singh ◽  
Krishna Kant Azad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Target ◽  
Drug Targets ◽  
Metabolic Networks ◽  
Carbon Fixation ◽  
New Drugs ◽  
Metabolic Adaptation ◽  
Potential Drug ◽  
Genes Encoding ◽  
Potential Drug Targets

Abstract Metabolic adaptation to the host environment has been recognized as an essential mechanism of pathogenicity and the growth of Mycobacterium tuberculosis (Mtb) in the lungs for decades. The Mtb uses CO2 as a source of carbon during the dormant or non-replicative state. However, there is a lack of biochemical knowledge of its metabolic networks. In this study, we investigated the CO2 fixation pathways (such as ko00710 and ko00720) most likely involved in the energy production and conversion of CO2 in Mtb. Extensive pathway evaluation of 23 completely sequenced strains of Mtb confirmed the existence of a complete list of genes encoding the relevant enzymes of the reductive tricarboxylic acid (rTCA) cycle. This provides the evidence that an rTCA cycle may function to fix CO2 in this bacterium. We also proposed that as CO2 is plentiful in the lungs, inhibition of CO2 fixation pathways (by targeting the relevant CO2 fixation enzymes) could be used in the expansion of new drugs against the dormant Mtb. In support of the suggested hypothesis, the CO2 fixation enzymes were confirmed as a potential drug target by analyzing a number of attributes necessary to be a good bacterial target.

scholarly journals Analysis of metabolic pathways in mycobacteria to aid drug-target identification

2019 ◽  
Author(s):  
Bridget P. Bannerman ◽  
Sundeep C. Vedithi ◽  
Jorge Júlvez ◽  
Pedro Torres ◽  
Vaishali P. Waman ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Causative Agent ◽  
Metabolic Pathways ◽  
Drug Target ◽  
Drug Targets ◽  
Opportunistic Infections ◽  
Target Identification ◽  
Treatment Strategies ◽  
New Drugs ◽  
Drug Target Identification

AbstractThree related mycobacteria are the cause of widespread infections in man and are the focus of intense research and drug-discovery efforts in the face of growing antimicrobial resistance.Mycobacterium tuberculosis, the causative agent of tuberculosis, is currently one of the top ten causes of death in the world according to WHO;M.abscessus, a group of non-tuberculous mycobacteria causes lung infections and other opportunistic infections in humans; andM.leprae, the causative agent of leprosy, remains endemic in tropical countries. There is an urgent need to design alternatives to conventional treatment strategies, due to the increase in resistance to standard antibacterials. In this study, we present a comparative analysis of chokepoint and essentiality datasets that will provide insight into the development of new treatment regimes. We illustrate the key metabolic pathways shared between these three organisms and identify drug targets with a wide metabolic impact that are common to the three species. We demonstrate that 72% of the chokepoint enzymes are proteins essential toMycobacterium tuberculosis. We show also that 78% of the drug targets, prioritized based on their presence in multiple paths on the metabolic network, are present in pathways shared byM. tuberculosis, M.lepraeandM.abscessus, including biosynthesis of amino acids, carbohydrates, cell structures, fatty acid and lipid biosynthesis. A further 17% is found in the prioritised pathways shared betweenM. tuberculosisandM.abscessus. We have performed comparative structure modelling of potential drug targets identified using our analysis in order to assess druggability and demonstrate the importance of chokepoint analysis in terms of drug target identification.AUTHOR SUMMARYComputer simulation studies to design new drugs against mycobacteria

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