1
|
Aktaş E, Özdemir Özgentürk N. A comprehensive examination of ACE2 receptor and prediction of spike glycoprotein and ACE2 interaction based on in silico analysis of ACE2 receptor. J Biomol Struct Dyn 2024; 42:4412-4428. [PMID: 37349943 DOI: 10.1080/07391102.2023.2220814] [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: 02/12/2023] [Accepted: 05/28/2023] [Indexed: 06/24/2023]
Abstract
The ACE2 receptor plays a vital role not only in the SARS-CoV-induced epidemic but also in various other diseases, including cardiovascular diseases and ARDS. While studies have explored the interactions between ACE2 and SARS-CoV proteins, comprehensive research utilizing bioinformatic tools on the ACE2 protein has been lacking. The one aim of present study was to extensively analyze the regions of the ACE2 protein. After utilizing all bioinformatics tools especially G104 and L108 regions on ACE2 were come forward. The results of our analysis revealed that possible mutations or deletions in the G104 and L108 regions play a critical role in both the biological functioning and the determination of the chemical-physical properties of ACE2. Additionally, these regions were found to be more susceptible to mutations or deletions compared to other regions of the ACE2 protein. Notably, the randomly selected peptide, LQQNGSSVLS (100-109), which includes G104 and L108, exhibited a crucial role in binding the RBD of the spike protein, as supported by docking scores. Furthermore, both MDs and iMODs results provided evidence that G104 and L108 influence the dynamics of ACE2-spike complexes. This study is expected to offer a new perspective on the ACE2-SARS-CoV interaction and other research areas where ACE2 plays a significant role, such as biotechnology (protein engineering, enzyme optimization), medicine (RAS, pulmonary and cardiac diseases), and basic research (structural motifs, stabilizing protein folds, or facilitating important inter molecular contacts, protein's proper structure and function).Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Emre Aktaş
- Faculty of Art and Science, Molecular Biology and Genetics, Yıldız Technical University, Istanbul, Turkey
| | - Nehir Özdemir Özgentürk
- Faculty of Art and Science, Molecular Biology and Genetics, Yıldız Technical University, Istanbul, Turkey
| |
Collapse
|
2
|
Khan S, Ahmad F, Ansari MI, Ashfaque M, Islam MH, Khubaib M. Toxin-Antitoxin system of Mycobacterium tuberculosis: Roles beyond stress sensor and growth regulator. Tuberculosis (Edinb) 2023; 143:102395. [PMID: 37722233 DOI: 10.1016/j.tube.2023.102395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/15/2023] [Accepted: 08/10/2023] [Indexed: 09/20/2023]
Abstract
The advent of effective drug regimen and BCG vaccine has significantly decreased the rate of morbidity and mortality of TB. However, lengthy treatment and slower recovery rate, as well as reactivation of the disease with the emergence of multi-drug, extensively-drug, and totally-drug resistance strains, pose a serious concern. The complexities associated are due to the highly evolved and complex nature of the bacterium itself. One of the unique features of Mycobacterium tuberculosis [M.tb] is that it has undergone reductive evolution while maintaining and amplified a few gene families. One of the critical gene family involved in the virulence and pathogenesis is the Toxin-Antitoxin system. These families are believed to harbor virulence signature and are strongly associated with various stress adaptations and pathogenesis. The M.tb TA systems are linked with growth regulation machinery during various environmental stresses. The genes of TA systems are differentially expressed in the host during an active infection, oxidative stress, low pH stress, and starvation, which essentially indicate their role beyond growth regulators. Here in this review, we have discussed different roles of TA gene families in various stresses and their prospective role at the host-pathogen interface, which could be exploited to understand the M.tb associated pathomechanisms better and further designing the new strategies against the pathogen.
Collapse
Affiliation(s)
- Saima Khan
- Department of Biosciences, Integral University, Lucknow, India
| | - Firoz Ahmad
- Department of Biosciences, Integral University, Lucknow, India
| | | | | | | | - Mohd Khubaib
- Department of Biosciences, Integral University, Lucknow, India.
| |
Collapse
|
3
|
Kang SM. Focused Overview of Mycobacterium tuberculosis VapBC Toxin-Antitoxin Systems Regarding Their Structural and Functional Aspects: Including Insights on Biomimetic Peptides. Biomimetics (Basel) 2023; 8:412. [PMID: 37754163 PMCID: PMC10526153 DOI: 10.3390/biomimetics8050412] [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: 08/23/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
Tuberculosis, caused by Mycobacterium tuberculosis, is a lethal infectious disease of significant public health concern. The rise of multidrug-resistant and drug-tolerant strains has necessitated novel approaches to combat the disease. Toxin-antitoxin (TA) systems, key players in bacterial adaptive responses, are prevalent in prokaryotic genomes and have been linked to tuberculosis. The genome of M. tuberculosis strains harbors an unusually high number of TA systems, prompting questions about their biological roles. The VapBC family, a representative type II TA system, is characterized by the VapC toxin, featuring a PilT N-terminal domain with nuclease activity. Its counterpart, VapB, functions as an antitoxin, inhibiting VapC's activity. Additionally, we explore peptide mimics designed to replicate protein helical structures in this review. Investigating these synthetic peptides offers fresh insights into molecular interactions, potentially leading to therapeutic applications. These synthetic peptides show promise as versatile tools for modulating cellular processes and protein-protein interactions. We examine the rational design strategies employed to mimic helical motifs, their biophysical properties, and potential applications in drug development and bioengineering. This review aims to provide an in-depth understanding of TA systems by introducing known complex structures, with a focus on both structural aspects and functional and molecular details associated with each system.
Collapse
Affiliation(s)
- Sung-Min Kang
- College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea
| |
Collapse
|
4
|
Xu X, Usher B, Gutierrez C, Barriot R, Arrowsmith TJ, Han X, Redder P, Neyrolles O, Blower TR, Genevaux P. MenT nucleotidyltransferase toxins extend tRNA acceptor stems and can be inhibited by asymmetrical antitoxin binding. Nat Commun 2023; 14:4644. [PMID: 37591829 PMCID: PMC10435456 DOI: 10.1038/s41467-023-40264-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023] Open
Abstract
Mycobacterium tuberculosis, the bacterium responsible for human tuberculosis, has a genome encoding a remarkably high number of toxin-antitoxin systems of largely unknown function. We have recently shown that the M. tuberculosis genome encodes four of a widespread, MenAT family of nucleotidyltransferase toxin-antitoxin systems. In this study we characterize MenAT1, using tRNA sequencing to demonstrate MenT1 tRNA modification activity. MenT1 activity is blocked by MenA1, a short protein antitoxin unrelated to the MenA3 kinase. X-ray crystallographic analysis shows blockage of the conserved MenT fold by asymmetric binding of MenA1 across two MenT1 protomers, forming a heterotrimeric toxin-antitoxin complex. Finally, we also demonstrate tRNA modification by toxin MenT4, indicating conserved activity across the MenT family. Our study highlights variation in tRNA target preferences by MenT toxins, selective use of nucleotide substrates, and diverse modes of MenA antitoxin activity.
Collapse
Affiliation(s)
- Xibing Xu
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Ben Usher
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Claude Gutierrez
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Roland Barriot
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Tom J Arrowsmith
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Xue Han
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Peter Redder
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Tim R Blower
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France.
| |
Collapse
|
5
|
Deep A, Singh L, Kaur J, Velusamy M, Bhardwaj P, Singh R, Thakur KG. Structural insights into DarT toxin neutralization by cognate DarG antitoxin: ssDNA mimicry by DarG C-terminal domain keeps the DarT toxin inhibited. Structure 2023; 31:780-789.e4. [PMID: 37167974 DOI: 10.1016/j.str.2023.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/20/2023] [Accepted: 04/14/2023] [Indexed: 05/13/2023]
Abstract
In the DarTG toxin-antitoxin system, the DarT toxin ADP-ribosylates single-stranded DNA (ssDNA), which stalls DNA replication and plays a crucial role in controlling bacterial growth and bacteriophage infection. This toxic activity is reversed by the N-terminal macrodomain of the cognate antitoxin DarG. DarG also binds DarT, but the role of these interactions in DarT neutralization is unknown. Here, we report that the C-terminal domain of DarG (DarG toxin-binding domain [DarGTBD]) interacts with DarT to form a 1:1 stoichiometric heterodimeric complex. We determined the 2.2 Å resolution crystal structure of the Mycobacterium tuberculosis DarT-DarGTBD complex. The comparative structural analysis reveals that DarGTBD interacts with DarT at the DarT/ssDNA interaction interface, thus sterically occluding substrate ssDNA binding and consequently inactivating toxin by direct protein-protein interactions. Our data support a unique two-layered DarT toxin neutralization mechanism of DarG, which is important in keeping the toxin molecules in check under normal growth conditions.
Collapse
Affiliation(s)
- Amar Deep
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Latika Singh
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Japleen Kaur
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Maheshwaran Velusamy
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Pushpanjali Bhardwaj
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India
| | - Ramandeep Singh
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh 160036, India.
| |
Collapse
|
6
|
Sau S, Roy A, Agnivesh PK, Kumar S, Guru SK, Sharma S, Kalia NP. Unravelling the flexibility of Mycobacterium tuberculosis: an escape way for the bacilli. J Med Microbiol 2023; 72. [PMID: 37261969 DOI: 10.1099/jmm.0.001695] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
The persistence of Mycobacterium tuberculosis makes it difficult to eradicate the associated infection from the host. The flexible nature of mycobacteria and their ability to adapt to adverse host conditions give rise to different drug-tolerant phenotypes. Granuloma formation restricts nutrient supply, limits oxygen availability and exposes bacteria to a low pH environment, resulting in non-replicating bacteria. These non-replicating mycobacteria, which need high doses and long exposure to anti-tubercular drugs, are the root cause of lengthy chemotherapy. Novel strategies, which are effective against non-replicating mycobacteria, need to be adopted to shorten tuberculosis treatment. This not only will reduce the treatment time but also will help prevent the emergence of multi-drug-resistant strains of mycobacteria.
Collapse
Affiliation(s)
- Shashikanta Sau
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Arnab Roy
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Puja Kumari Agnivesh
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Sunil Kumar
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Santosh Kumar Guru
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Sandeep Sharma
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, Punjab -144411, India
| | - Nitin Pal Kalia
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| |
Collapse
|
7
|
Kang SM. Mycobacterium tuberculosis Rv0229c Shows Ribonuclease Activity and Reveals Its Corresponding Role as Toxin VapC51. Antibiotics (Basel) 2023; 12:antibiotics12050840. [PMID: 37237743 DOI: 10.3390/antibiotics12050840] [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: 03/28/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
The VapBC system, which belongs to the type II toxin-antitoxin (TA) system, is the most abundant and widely studied system in Mycobacterium tuberculosis. The VapB antitoxin suppresses the activity of the VapC toxin through a stable protein-protein complex. However, under environmental stress, the balance between toxin and antitoxin is disrupted, leading to the release of free toxin and bacteriostatic state. This study introduces the Rv0229c, a putative VapC51 toxin, and aims to provide a better understanding of its discovered function. The structure of the Rv0229c shows a typical PIN-domain protein, exhibiting an β1-α1-α2-β2-α3-α4-β3-α5-α6-β4-α7-β5 topology. The structure-based sequence alignment showed four electronegative residues in the active site of Rv0229c, which is composed of Asp8, Glu42, Asp95, and Asp113. By comparing the active site with existing VapC proteins, we have demonstrated the justification for naming it VapC51 at the molecular level. In an in vitro ribonuclease activity assay, Rv0229c showed ribonuclease activity dependent on the concentration of metal ions such as Mg2+ and Mn2+. In addition, magnesium was found to have a greater effect on VapC51 activity than manganese. Through these structural and experimental studies, we provide evidence for the functional role of Rv0229c as a VapC51 toxin. Overall, this study aims to enhance our understanding of the VapBC system in M. tuberculosis.
Collapse
Affiliation(s)
- Sung-Min Kang
- College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea
| |
Collapse
|
8
|
Sundaram K, Vajravelu LK, Paul AJ. Functional characterization of toxin-antitoxin system in Mycobacterium tuberculosis. Indian J Tuberc 2023; 70:149-157. [PMID: 37100570 DOI: 10.1016/j.ijtb.2022.05.010] [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: 01/20/2022] [Revised: 05/06/2022] [Accepted: 05/20/2022] [Indexed: 04/28/2023]
Abstract
Toxin-Antitoxin (TA) system is abundant in the microbial genome, especially in bacteria and archaea. Its genetic elements and addiction modules with the role of bacterial persistence and virulence. The TA system consists of a toxin and most unstable antitoxin that could be a protein or non-encoded RNA, TA loci are chromosomally determined and their cellular functions are mostly unknown. Approximately 93 TA systems were demonstrated and more functionally available in M. tuberculosis (Mtb), the organism responsible for tuberculosis (TB). It is an airborne disease, which is causing ill-health to humans. M. tuberculosis possesses higher TA loci than other microbes and non-tubercle bacilli, the following TA types have been identified such as VapBC, MazEF, HigBA, RelBE, ParDE, DarTG, PemIK, MbcTA, and one tripartite type II TAC-Chaperone system. Toxin-antitoxin Database (TADB) brings a detailed update on Toxin-Antitoxin classification in the different pathogens such as staphylococcus aureus, streptococcus pneumonia, Vibrio cholerae, Salmonella typhimurium, Shigella flexneri, and helicobacter pylori, etc. So, this Toxin-Antitoxin system is a master regulator for bacterial growth, and an essential factor in analyzing the properties and function of disease persistence, biofilm formation, and pathogenicity. The TA system is an advanced tool to develop a new therapeutic agent against M. tuberculosis.
Collapse
Affiliation(s)
- Karthikeyan Sundaram
- Department of Microbiology, SRM Medical College Hospital and Research Centre, Kattangulathur, Chennai, 603203, Tamilnadu, India.
| | - Leela Kagithakara Vajravelu
- Department of Microbiology, SRM Medical College Hospital and Research Centre, Kattangulathur, Chennai, 603203, Tamilnadu, India
| | - Alamu Juliana Paul
- Department of Microbiology, SRM Medical College Hospital and Research Centre, Kattangulathur, Chennai, 603203, Tamilnadu, India
| |
Collapse
|
9
|
Chauhan NK, Anand A, Sharma A, Dhiman K, Gosain TP, Singh P, Singh P, Khan E, Chattopadhyay G, Kumar A, Sharma D, Ashish, Sharma TK, Singh R. Structural and Functional Characterization of Rv0792c from Mycobacterium tuberculosis: Identifying Small Molecule Inhibitor against HutC Protein. Microbiol Spectr 2023; 11:e0197322. [PMID: 36507689 PMCID: PMC9927256 DOI: 10.1128/spectrum.01973-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In order to adapt in host tissues, microbial pathogens regulate their gene expression through a variety of transcription factors. Here, we have functionally characterized Rv0792c, a HutC homolog from Mycobacterium tuberculosis. In comparison to the parental strain, a strain of M. tuberculosis with a Rv0792c mutant was compromised for survival upon exposure to oxidative stress and infection in guinea pigs. RNA sequencing analysis revealed that Rv0792c regulates the expression of genes involved in stress adaptation and virulence of M. tuberculosis. Solution small-angle X-ray scattering (SAXS) data-steered model building confirmed that the C-terminal region plays a pivotal role in dimer formation. Systematic evolution of ligands by exponential enrichment (SELEX) resulted in the identification of single-strand DNA (ssDNA) aptamers that can be used as a tool to identify small-molecule inhibitors targeting Rv0792c. Using SELEX and SAXS data-based modeling, we identified residues essential for Rv0792c's aptamer binding activity. In this study, we also identified I-OMe-Tyrphostin as an inhibitor of Rv0792c's aptamer and DNA binding activity. The identified small molecule reduced the growth of intracellular M. tuberculosis in macrophages. The present study thus provides a detailed shape-function characterization of a HutC family of transcription factor from M. tuberculosis. IMPORTANCE Prokaryotes encode a large number of GntR family transcription factors that are involved in various fundamental biological processes, including stress adaptation and pathogenesis. Here, we investigated the structural and functional role of Rv0792c, a HutC homolog from M. tuberculosis. We demonstrated that Rv0792c is essential for M. tuberculosis to adapt to oxidative stress and establish disease in guinea pigs. Using a systematic evolution of ligands by exponential enrichment (SELEX) approach, we identified ssDNA aptamers from a random ssDNA library that bound to Rv0792c protein. These aptamers were thoroughly characterized using biochemical and biophysical assays. Using SAXS, we determined the structural model of Rv0792c in both the presence and absence of the aptamers. Further, using a combination of SELEX and SAXS methodologies, we identified I-OMe-Tyrphostin as a potential inhibitor of Rv0792c. Here we provide a detailed functional characterization of a transcription factor belonging to the HutC family from M. tuberculosis.
Collapse
Affiliation(s)
- Neeraj Kumar Chauhan
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Anjali Anand
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Arun Sharma
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Kanika Dhiman
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Tannu Priya Gosain
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Prashant Singh
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Padam Singh
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Eshan Khan
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indoregrid.450280.b, Indore, India
| | | | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indoregrid.450280.b, Indore, India
| | - Deepak Sharma
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Ashish
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Tarun Kumar Sharma
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Ramandeep Singh
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| |
Collapse
|
10
|
Gosain TP, Singh M, Singh C, Thakur KG, Singh R. Disruption of MenT2 toxin impairs the growth of Mycobacterium tuberculosis in guinea pigs. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36342835 DOI: 10.1099/mic.0.001246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Toxin-antitoxin (TA) systems are abundantly present in the genomes of various bacterial pathogens. TA systems have been implicated in either plasmid maintenance or protection against phage infection, stress adaptation or disease pathogenesis. The genome of Mycobacterium tuberculosis encodes for more than 90 TA systems and 4 of these belong to the type IV subfamily (MenAT family). The toxins and antitoxins belonging to type IV TA systems share sequence homology with the AbiEii family of nucleotidyl transferases and the AbiEi family of putative transcriptional regulators, respectively. Here, we have performed experiments to understand the role of MenT2, a toxin from the type IV TA system, in mycobacterial physiology and disease pathogenesis. The ectopic expression of MenT2 using inducible vectors does not inhibit bacterial growth in liquid cultures. Bioinformatic and molecular modelling analysis suggested that the M. tuberculosis genome has an alternative start site upstream of the annotated menT2 gene. The overexpression of the reannotated MenT2 resulted in moderate growth inhibition of Mycobacterium smegmatis. We show that both menT2 and menA2 transcript levels are increased when M. tuberculosis is exposed to nitrosative stress, in vitro. When compared to the survival of the wild-type and the complemented strain, the ΔmenT2 mutant strain of M. tuberculosis was more resistant to being killed by nitrosative stress. However, the survival of both the ΔmenT2 mutant and the wild-type strain was similar in macrophages and when exposed to other stress conditions. Here, we show that MenT2 is required for the establishment of disease in guinea pigs. Gross pathology and histopathology analysis of lung tissues from guinea pigs infected with the ∆menT2 strain revealed significantly reduced tissue damage and inflammation. In summary, these results provide new insights into the role of MenT2 in mycobacterial pathogenesis.
Collapse
Affiliation(s)
- Tannu Priya Gosain
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| | - Manisha Singh
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| | - Charandeep Singh
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh-160036, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh-160036, India
| | - Ramandeep Singh
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| |
Collapse
|
11
|
Qiu J, Zhai Y, Wei M, Zheng C, Jiao X. Toxin–antitoxin systems: Classification, biological roles, and applications. Microbiol Res 2022; 264:127159. [DOI: 10.1016/j.micres.2022.127159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/28/2022]
|
12
|
Mansour M, Giudice E, Xu X, Akarsu H, Bordes P, Guillet V, Bigot DJ, Slama N, D'urso G, Chat S, Redder P, Falquet L, Mourey L, Gillet R, Genevaux P. Substrate recognition and cryo-EM structure of the ribosome-bound TAC toxin of Mycobacterium tuberculosis. Nat Commun 2022; 13:2641. [PMID: 35552387 PMCID: PMC9098466 DOI: 10.1038/s41467-022-30373-w] [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: 02/04/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022] Open
Abstract
Toxins of toxin-antitoxin systems use diverse mechanisms to control bacterial growth. Here, we focus on the deleterious toxin of the atypical tripartite toxin-antitoxin-chaperone (TAC) system of Mycobacterium tuberculosis, whose inhibition requires the concerted action of the antitoxin and its dedicated SecB-like chaperone. We show that the TAC toxin is a bona fide ribonuclease and identify exact cleavage sites in mRNA targets on a transcriptome-wide scale in vivo. mRNA cleavage by the toxin occurs after the second nucleotide of the ribosomal A-site codon during translation, with a strong preference for CCA codons in vivo. Finally, we report the cryo-EM structure of the ribosome-bound TAC toxin in the presence of native M. tuberculosis cspA mRNA, revealing the specific mechanism by which the TAC toxin interacts with the ribosome and the tRNA in the P-site to cleave its mRNA target. Toxin-antitoxin systems are widespread in bacteria. Here the authors present structures of M. tuberculosis HigBTAC alone and bound to the ribosome in the presence of native cspA mRNA, shedding light on its mechanism of translation inhibition.
Collapse
Affiliation(s)
- Moise Mansour
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Emmanuel Giudice
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Xibing Xu
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Hatice Akarsu
- Department of Biology, University of Fribourg & Swiss Institute of Bioinformatics, Fribourg, Switzerland.,Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Patricia Bordes
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Donna-Joe Bigot
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France.,Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Nawel Slama
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Gaetano D'urso
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Sophie Chat
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Peter Redder
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Laurent Falquet
- Department of Biology, University of Fribourg & Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Reynald Gillet
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France.
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France.
| |
Collapse
|
13
|
Chattopadhyay G, Bhasin M, Ahmed S, Gosain TP, Ganesan S, Das S, Thakur C, Chandra N, Singh R, Varadarajan R. Functional and Biochemical Characterization of the MazEF6 Toxin-Antitoxin System of Mycobacterium tuberculosis. J Bacteriol 2022; 204:e0005822. [PMID: 35357163 PMCID: PMC9053165 DOI: 10.1128/jb.00058-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/07/2022] [Indexed: 12/15/2022] Open
Abstract
The Mycobacterium tuberculosis genome harbors nine toxin-antitoxin (TA) systems that are members of the mazEF family, unlike other prokaryotes, which have only one or two. Although the overall tertiary folds of MazF toxins are predicted to be similar, it is unclear how they recognize structurally different RNAs and antitoxins with divergent sequence specificity. Here, we have expressed and purified the individual components and complex of the MazEF6 TA system from M. tuberculosis. Size exclusion chromatography-multiangle light scattering (SEC-MALS) was performed to determine the oligomerization status of the toxin, antitoxin, and the complex in different stoichiometric ratios. The relative stabilities of the proteins were determined by nano-differential scanning fluorimetry (nano-DSF). Microscale thermophoresis (MST) and yeast surface display (YSD) were performed to measure the relative affinities between the cognate toxin-antitoxin partners. The interaction between MazEF6 complexes and cognate promoter DNA was also studied using MST. Analysis of paired-end RNA sequencing data revealed that the overexpression of MazF6 resulted in differential expression of 323 transcripts in M. tuberculosis. Network analysis was performed to identify the nodes from the top-response network. The analysis of mRNA protection ratios resulted in identification of putative MazF6 cleavage site in its native host, M. tuberculosis. IMPORTANCE M. tuberculosis harbors a large number of type II toxin-antitoxin (TA) systems, the exact roles for most of which are unclear. Prior studies have reported that overexpression of several of these type II toxins inhibits bacterial growth and contributes to the formation of drug-tolerant populations in vitro. To obtain insights into M. tuberculosis MazEF6 type II TA system function, we determined stability, oligomeric states, and binding affinities of cognate partners with each other and with their promoter operator DNA. Using RNA-seq data obtained from M. tuberculosis overexpression strains, we have identified putative MazF6 cleavage sites and targets in its native, cellular context.
Collapse
Affiliation(s)
| | - Munmun Bhasin
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Shahbaz Ahmed
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Tannu Priya Gosain
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Srivarshini Ganesan
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Sayan Das
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Ramandeep Singh
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Raghavan Varadarajan
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| |
Collapse
|
14
|
Sharma A, Sagar K, Chauhan NK, Venkataraman B, Gupta N, Gosain TP, Bhalla N, Singh R, Gupta A. HigB1 Toxin in Mycobacterium tuberculosis Is Upregulated During Stress and Required to Establish Infection in Guinea Pigs. Front Microbiol 2021; 12:748890. [PMID: 34917044 PMCID: PMC8669151 DOI: 10.3389/fmicb.2021.748890] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/29/2021] [Indexed: 12/20/2022] Open
Abstract
The extraordinary expansion of Toxin Antitoxin (TA) modules in the genome of Mycobacterium tuberculosis has received significant attention over the last few decades. The cumulative evidence suggests that TA systems are activated in response to stress conditions and are essential for M. tuberculosis pathogenesis. In M. tuberculosis, Rv1955-Rv1956-Rv1957 constitutes the only tripartite TAC (Toxin Antitoxin Chaperone) module. In this locus, Rv1955 (HigB1) encodes for the toxin and Rv1956 (HigA1) encodes for antitoxin. Rv1957 encodes for a SecB-like chaperone that regulates HigBA1 toxin antitoxin system by preventing HigA1 degradation. Here, we have investigated the physiological role of HigB1 toxin in stress adaptation and pathogenesis of Mycobacterium tuberculosis. qPCR studies revealed that higBA1 is upregulated in nutrient limiting conditions and upon exposure to levofloxacin. We also show that the promoter activity of higBA1 locus in M. tuberculosis is (p)ppGpp dependent. We observed that HigB1 locus is non-essential for M. tuberculosis growth under different stress conditions in vitro. However, guinea pigs infected with higB1 deletion strain exhibited significantly reduced bacterial loads and pathological damage in comparison to the animals infected with the parental strain. Transcriptome analysis suggested that deletion of higB1 reduced the expression of genes involved in virulence, detoxification and adaptation. The present study describes the role of higB1 toxin in M. tuberculosis physiology and highlights the importance of higBA1 locus during infection in host tissues.
Collapse
Affiliation(s)
- Arun Sharma
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Kalpana Sagar
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India.,Centre for Innovation in Infectious Disease Research, Education and Training, New Delhi, India
| | - Neeraj Kumar Chauhan
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Balaji Venkataraman
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Nidhi Gupta
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Tannu Priya Gosain
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Nikhil Bhalla
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Ramandeep Singh
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Amita Gupta
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India.,Centre for Innovation in Infectious Disease Research, Education and Training, New Delhi, India
| |
Collapse
|
15
|
Kamruzzaman M, Wu AY, Iredell JR. Biological Functions of Type II Toxin-Antitoxin Systems in Bacteria. Microorganisms 2021; 9:microorganisms9061276. [PMID: 34208120 PMCID: PMC8230891 DOI: 10.3390/microorganisms9061276] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 12/14/2022] Open
Abstract
After the first discovery in the 1980s in F-plasmids as a plasmid maintenance system, a myriad of toxin-antitoxin (TA) systems has been identified in bacterial chromosomes and mobile genetic elements (MGEs), including plasmids and bacteriophages. TA systems are small genetic modules that encode a toxin and its antidote and can be divided into seven types based on the nature of the antitoxin molecules and their mechanism of action to neutralise toxins. Among them, type II TA systems are widely distributed in chromosomes and plasmids and the best studied so far. Maintaining genetic material may be the major function of type II TA systems associated with MGEs, but the chromosomal TA systems contribute largely to functions associated with bacterial physiology, including the management of different stresses, virulence and pathogenesis. Due to growing interest in TA research, extensive work has been conducted in recent decades to better understand the physiological roles of these chromosomally encoded modules. However, there are still controversies about some of the functions associated with different TA systems. This review will discuss the most current findings and the bona fide functions of bacterial type II TA systems.
Collapse
Affiliation(s)
- Muhammad Kamruzzaman
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
- Correspondence: (M.K.); (J.R.I.)
| | - Alma Y. Wu
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
| | - Jonathan R. Iredell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
- Westmead Hospital, Westmead, NSW 2145, Australia
- Correspondence: (M.K.); (J.R.I.)
| |
Collapse
|
16
|
Bordes P, Genevaux P. Control of Toxin-Antitoxin Systems by Proteases in Mycobacterium Tuberculosis. Front Mol Biosci 2021; 8:691399. [PMID: 34079824 PMCID: PMC8165232 DOI: 10.3389/fmolb.2021.691399] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 12/30/2022] Open
Abstract
Toxin-antitoxin (TA) systems are small genetic elements composed of a noxious toxin and a counteracting cognate antitoxin. Although they are widespread in bacterial chromosomes and in mobile genetic elements, their cellular functions and activation mechanisms remain largely unknown. It has been proposed that toxin activation or expression of the TA operon could rely on the degradation of generally less stable antitoxins by cellular proteases. The resulting active toxin would then target essential cellular processes and inhibit bacterial growth. Although interplay between proteases and TA systems has been observed, evidences for such activation cycle are very limited. Herein, we present an overview of the current knowledge on TA recognition by proteases with a main focus on the major human pathogen Mycobacterium tuberculosis, which harbours multiple TA systems (over 80), the essential AAA + stress proteases, ClpC1P1P2 and ClpXP1P2, and the Pup-proteasome system.
Collapse
Affiliation(s)
- Patricia Bordes
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| |
Collapse
|
17
|
Kahan R, Worm DJ, de Castro GV, Ng S, Barnard A. Modulators of protein-protein interactions as antimicrobial agents. RSC Chem Biol 2021; 2:387-409. [PMID: 34458791 PMCID: PMC8341153 DOI: 10.1039/d0cb00205d] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
Protein-Protein interactions (PPIs) are involved in a myriad of cellular processes in all living organisms and the modulation of PPIs is already under investigation for the development of new drugs targeting cancers, autoimmune diseases and viruses. PPIs are also involved in the regulation of vital functions in bacteria and, therefore, targeting bacterial PPIs offers an attractive strategy for the development of antibiotics with novel modes of action. The latter are urgently needed to tackle multidrug-resistant and multidrug-tolerant bacteria. In this review, we describe recent developments in the modulation of PPIs in pathogenic bacteria for antibiotic development, including advanced small molecule and peptide inhibitors acting on bacterial PPIs involved in division, replication and transcription, outer membrane protein biogenesis, with an additional focus on toxin-antitoxin systems as upcoming drug targets.
Collapse
Affiliation(s)
- Rashi Kahan
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 82 Wood Lane London W12 0BZ UK
| | - Dennis J Worm
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 82 Wood Lane London W12 0BZ UK
| | - Guilherme V de Castro
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 82 Wood Lane London W12 0BZ UK
| | - Simon Ng
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 82 Wood Lane London W12 0BZ UK
| | - Anna Barnard
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 82 Wood Lane London W12 0BZ UK
| |
Collapse
|
18
|
Kang SM, Jin C, Kim DH, Lee Y, Lee BJ. Structural and Functional Study of the Klebsiella pneumoniae VapBC Toxin-Antitoxin System, Including the Development of an Inhibitor That Activates VapC. J Med Chem 2020; 63:13669-13679. [PMID: 33146528 DOI: 10.1021/acs.jmedchem.0c01118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Klebsiella pneumoniae is one of the most critical opportunistic pathogens. TA systems are promising drug targets because they are related to the survival of bacterial pathogens. However, structural information on TA systems in K. pneumoniae remains lacking; therefore, it is necessary to explore this information for the development of antibacterial agents. Here, we present the first crystal structure of the VapBC complex from K. pneumoniae at a resolution of 2.00 Å. We determined the toxin inhibitory mechanism of the VapB antitoxin through an Mg2+ switch, in which Mg2+ is displaced by R79 of VapB. This inhibitory mechanism of the active site is a novel finding and the first to be identified in a bacterial TA system. Furthermore, inhibitors, including peptides and small molecules, that activate the VapC toxin were discovered and investigated. These inhibitors can act as antimicrobial agents by disrupting the VapBC complex and activating VapC. Our comprehensive investigation of the K. pneumoniae VapBC system will help elucidate an unsolved conundrum in VapBC systems and develop potential antimicrobial agents.
Collapse
Affiliation(s)
- Sung-Min Kang
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Chenglong Jin
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Do-Hee Kim
- College of Pharmacy, Jeju National University, Jeju 63243, Korea.,Interdisciplinary Graduate Program in Advanced Convergence Technology & Science, Jeju National University, Jeju 63243, Korea
| | - Yuno Lee
- Korea Chemical Bank, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Bong-Jin Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
19
|
Sharma A, Chattopadhyay G, Chopra P, Bhasin M, Thakur C, Agarwal S, Ahmed S, Chandra N, Varadarajan R, Singh R. VapC21 Toxin Contributes to Drug-Tolerance and Interacts With Non-cognate VapB32 Antitoxin in Mycobacterium tuberculosis. Front Microbiol 2020; 11:2037. [PMID: 33042034 PMCID: PMC7517352 DOI: 10.3389/fmicb.2020.02037] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/31/2020] [Indexed: 12/13/2022] Open
Abstract
The prokaryotic ubiquitous Toxin-antitoxin (TA) modules encodes for a stable toxin and an unstable antitoxin. VapBC subfamily is the most abundant Type II TA system in M. tuberculosis genome. However, the exact physiological role for most of these Type II TA systems are still unknown. Here, we have comprehensively characterized the VapBC21 TA locus from M. tuberculosis. The overexpression of VapC21 inhibited mycobacterial growth in a bacteriostatic manner and as expected, growth inhibition was abrogated upon co-expression of the cognate antitoxin, VapB21. We observed that the deletion of vapC21 had no noticeable influence on the in vitro and in vivo growth of M. tuberculosis. Using co-expression and biophysical studies, we observed that in addition to VapB21, VapC21 is also able to interact with non-cognate antitoxin, VapB32. The strength of interaction varied between the cognate and non-cognate TA pairs. The overexpression of VapC21 resulted in differential expression of approximately 435 transcripts in M. tuberculosis. The transcriptional profiles obtained upon ectopic expression of VapC21 was similar to those reported in M. tuberculosis upon exposure to stress conditions such as nutrient starvation and enduring hypoxic response. Further, VapC21 overexpression also led to increased expression of WhiB7 regulon and bacterial tolerance to aminoglycosides and ethambutol. Taken together, these results indicate that a complex network of interactions exists between non-cognate TA pairs and VapC21 contributes to drug tolerance in vitro.
Collapse
Affiliation(s)
- Arun Sharma
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | | | - Pankaj Chopra
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Munmun Bhasin
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Sakshi Agarwal
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| | - Shahbaz Ahmed
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Raghavan Varadarajan
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Ramandeep Singh
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, Faridabad, India
| |
Collapse
|
20
|
Tandon H, Melarkode Vattekatte A, Srinivasan N, Sandhya S. Molecular and Structural Basis of Cross-Reactivity in M. tuberculosis Toxin-Antitoxin Systems. Toxins (Basel) 2020; 12:E481. [PMID: 32751054 PMCID: PMC7472061 DOI: 10.3390/toxins12080481] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 01/12/2023] Open
Abstract
Mycobacterium tuberculosis genome encodes over 80 toxin-antitoxin (TA) systems. While each toxin interacts with its cognate antitoxin, the abundance of TA systems presents an opportunity for potential non-cognate interactions. TA systems mediate manifold interactions to manage pathogenicity and stress response network of the cell and non-cognate interactions may play vital roles as well. To address if non-cognate and heterologous interactions are feasible and to understand the structural basis of their interactions, we have performed comprehensive computational analyses on the available 3D structures and generated structural models of paralogous M. tuberculosis VapBC and MazEF TA systems. For a majority of the TA systems, we show that non-cognate toxin-antitoxin interactions are structurally incompatible except for complexes like VapBC15 and VapBC11, which show similar interfaces and potential for cross-reactivity. For TA systems which have been experimentally shown earlier to disfavor non-cognate interactions, we demonstrate that they are structurally and stereo-chemically incompatible. For selected TA systems, our detailed structural analysis identifies specificity conferring residues. Thus, our work improves the current understanding of TA interfaces and generates a hypothesis based on congenial binding site, geometric complementarity, and chemical nature of interfaces. Overall, our work offers a structure-based explanation for non-cognate toxin-antitoxin interactions in M. tuberculosis.
Collapse
Affiliation(s)
- Himani Tandon
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; (H.T.); (A.M.V.)
| | - Akhila Melarkode Vattekatte
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; (H.T.); (A.M.V.)
- Biologie Intégrée du Globule Rouge UMR_S1134, INSERM, Université Paris, Université de la Réunion, Université des Antilles, F-75739 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75739 Paris, France
- Faculté des Sciences et Technologies, Saint Denis Messag, F-97715 La Réunion, France
- Institut National de la Transfusion Sanguine (INTS), F-75739 Paris, France
| | - Narayanaswamy Srinivasan
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; (H.T.); (A.M.V.)
| | - Sankaran Sandhya
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; (H.T.); (A.M.V.)
| |
Collapse
|
21
|
Agarwal S, Sharma A, Bouzeyen R, Deep A, Sharma H, Mangalaparthi KK, Datta KK, Kidwai S, Gowda H, Varadarajan R, Sharma RD, Thakur KG, Singh R. VapBC22 toxin-antitoxin system from Mycobacterium tuberculosis is required for pathogenesis and modulation of host immune response. SCIENCE ADVANCES 2020; 6:eaba6944. [PMID: 32537511 PMCID: PMC7269643 DOI: 10.1126/sciadv.aba6944] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/02/2020] [Indexed: 05/16/2023]
Abstract
Virulence-associated protein B and C toxin-antitoxin (TA) systems are widespread in prokaryotes, but their precise role in physiology is poorly understood. We have functionally characterized the VapBC22 TA system from Mycobacterium tuberculosis. Transcriptome analysis revealed that overexpression of VapC22 toxin in M. tuberculosis results in reduced levels of metabolic enzymes and increased levels of ribosomal proteins. Proteomics studies showed reduced expression of virulence-associated proteins and increased levels of cognate antitoxin, VapB22 in the ΔvapC22 mutant strain. Furthermore, both the ΔvapC22 mutant and VapB22 overexpression strains of M. tuberculosis were susceptible to killing upon exposure to oxidative stress and showed attenuated growth in guinea pigs and mice. Host transcriptome analysis suggests upregulation of the transcripts involved in innate immune responses and tissue remodeling in mice infected with the ΔvapC22 mutant strain. Together, we demonstrate that the VapBC22 TA system belongs to a key regulatory network and is essential for M. tuberculosis pathogenesis.
Collapse
Affiliation(s)
- Sakshi Agarwal
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Harya na-121001, India
| | - Arun Sharma
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Harya na-121001, India
| | - Rania Bouzeyen
- Institut Pasteur de Tunis, LTCII, LR11IPT02, Tunis 1002, Tunisia
| | - Amar Deep
- Structural Biology Laboratory, Council of Scientific and Industrial Research–Institute of Microbial Technology, Chandigarh 160036, India
| | - Harsh Sharma
- Amity Institute of Integrative Sciences and Health, Amity University Haryana, Manesar, Gurugr am-122413, India
| | | | | | - Saqib Kidwai
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Harya na-121001, India
| | - Harsha Gowda
- Institute of Bioinformatics, Bangalore 560066, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore 575018, India
| | | | - Ravi Datta Sharma
- Amity Institute of Integrative Sciences and Health, Amity University Haryana, Manesar, Gurugr am-122413, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, Council of Scientific and Industrial Research–Institute of Microbial Technology, Chandigarh 160036, India
| | - Ramandeep Singh
- Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Harya na-121001, India
- Corresponding author.
| |
Collapse
|
22
|
Characterization of a toxin-antitoxin system in Mycobacterium tuberculosis suggests neutralization by phosphorylation as the antitoxicity mechanism. Commun Biol 2020; 3:216. [PMID: 32382148 PMCID: PMC7205606 DOI: 10.1038/s42003-020-0941-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/10/2020] [Indexed: 01/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) encodes an exceptionally large number of toxin-antitoxin (TA) systems, supporting the hypothesis that TA systems are involved in pathogenesis. We characterized the putative Mtb Rv1044-Rv1045 TA locus structurally and functionally, demonstrating that it constitutes a bona fide TA system but adopts a previously unobserved antitoxicity mechanism involving phosphorylation of the toxin. While Rv1045 encodes the guanylyltransferase TglT functioning as a toxin, Rv1044 encodes the novel atypical serine protein kinase TakA, which specifically phosphorylates the cognate toxin at residue S78, thereby neutralizing its toxicity. In contrast to previous predictions, we found that Rv1044-Rv1045 does not belong to the type IV TA family because TglT and TakA interact with each other as substrate and kinase, suggesting an unusual type of TA system. Protein homology analysis suggests that other COG5340-DUF1814 protein pairs, two highly associated but uncharacterized protein families widespread in prokaryotes, might share this unusual antitoxicity mechanism. Xia Yu et al. report the characterization of a toxin-antitoxin system with an unusual mechanism in Mycobacterium tuberculosis. They find that the antitoxin locus Rv1044 encodes an atypical serine protein kinase that phosphorylates the toxin to neutralize toxicity.
Collapse
|
23
|
Yan Y, Tao H, He J, Huang SY. The HDOCK server for integrated protein–protein docking. Nat Protoc 2020; 15:1829-1852. [DOI: 10.1038/s41596-020-0312-x] [Citation(s) in RCA: 288] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 02/03/2020] [Indexed: 12/27/2022]
|
24
|
|
25
|
Abstract
Protein-protein and protein-DNA/RNA interactions are involved in many cellular processes. Therefore, determining their complex structures at the atomic level is valuable to gain insights into these interactions. Because of the technical difficulties and high cost in experimental methods, computational approaches like molecular docking have been developed to predict the structures of macromolecular complexes in the last decades. To automatically integrate the available binding information from the PDB, we have developed HDOCK, a protein-protein/nucleic acid docking web server by combining template-based and free docking. In this chapter, we first briefly introduce our HDOCK server and then give a step-by-step description of docking bovine chymotrypsinogen A against its inhibitor (PDB ID: 1CGI). Two case studies of realistic examples are also discussed. The HDOCK server is freely available at http://hdock.phys.hust.edu.cn/ .
Collapse
Affiliation(s)
- Yumeng Yan
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Sheng-You Huang
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| |
Collapse
|
26
|
Behera S, Pattnaik S. Persister cell development among Enterobacteriaceae, Pseudomonadaceae, Mycobacteriaceae and Staphylococcaceae biotypes: A review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
27
|
Crystal Structure of VapBC-1 from Nontypeable Haemophilus influenzae and the Effect of PIN Domain Mutations on Survival during Infection. J Bacteriol 2019; 201:JB.00026-19. [PMID: 30936373 DOI: 10.1128/jb.00026-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/29/2019] [Indexed: 12/15/2022] Open
Abstract
Toxin-antitoxin (TA) gene pairs have been identified in nearly all bacterial genomes sequenced to date and are thought to facilitate persistence and antibiotic tolerance. TA loci are classified into various types based upon the characteristics of their antitoxins, with those in type II expressing proteic antitoxins. Many toxins from type II modules are ribonucleases that maintain a PilT N-terminal (PIN) domain containing conserved amino acids considered essential for activity. The vapBC (virulence-associated protein) TA system is the largest subfamily in this class and has been linked to pathogenesis of nontypeable Haemophilus influenzae (NTHi). In this study, the crystal structure of the VapBC-1 complex from NTHi was determined to 2.20 Å resolution. Based on this structure, aspartate-to-asparagine and glutamate-to-glutamine mutations of four conserved residues in the PIN domain of the VapC-1 toxin were constructed and the effects of the mutations on protein-protein interactions, growth of Escherichia coli, and pathogenesis ex vivo were tested. Finally, a novel model system was designed and utilized that consists of an NTHi ΔvapBC-1 strain complemented in cis with the TA module containing a mutated or wild-type toxin at an ectopic site on the chromosome. This enabled the analysis of the effect of PIN domain toxin mutants in tandem with their wild-type antitoxin under the control of the vapBC-1 native promoter and in single copy. This is the first report of a system facilitating the study of TA mutant operons in the background of NTHi during infections of primary human tissues ex vivo IMPORTANCE Herein the crystal structure of the VapBC-1 complex from nontypeable Haemophilus influenzae (NTHi) is described. Our results show that some of the mutations in the PIN domain of the VapC-1 toxin were associated with decreased toxicity in E. coli, but the mutants retained the ability to homodimerize and to heterodimerize with the wild-type cognate antitoxin, VapB-1. A new system was designed and constructed to quantify the effects of these mutations on NTHi survival during infections of primary human tissues ex vivo Any mutation to a conserved amino acid in the PIN domain significantly decreased the number of survivors compared to that of the in cis wild-type toxin under the same conditions.
Collapse
|
28
|
Cintrón M, Zeng JM, Barth VC, Cruz JW, Husson RN, Woychik NA. Accurate target identification for Mycobacterium tuberculosis endoribonuclease toxins requires expression in their native host. Sci Rep 2019; 9:5949. [PMID: 30976025 PMCID: PMC6459853 DOI: 10.1038/s41598-019-41548-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/01/2019] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium tuberculosis genome harbors an unusually high number of toxin-antitoxin (TA) systems. These TA systems have been implicated in establishing the nonreplicating persistent state of this pathogen during latent tuberculosis infection. More than half of the M. tuberculosis TA systems belong to the VapBC (virulence associated protein) family. In this work, we first identified the RNA targets for the M. tuberculosis VapC-mt11 (VapC11, Rv1561) toxin in vitro to learn more about the general function of this family of toxins. Recombinant VapC-mt11 cleaved 15 of the 45 M. tuberculosis tRNAs at a single site within their anticodon stem loop (ASL) to generate tRNA halves. Cleavage was dependent on the presence of a GG consensus sequence immediately before the cut site and a structurally intact ASL. However, in striking contrast to the broad enzyme activity exhibited in vitro, we used a specialized RNA-seq method to demonstrate that tRNA cleavage was highly specific in vivo. Expression of VapC-mt11 in M. tuberculosis resulted in cleavage of only two tRNA isoacceptors containing the GG consensus sequence, tRNAGln32-CUG and tRNALeu3-CAG. Therefore, our results indicate that although in vitro studies are useful for identification of the class of RNA cleaved and consensus sequences required for accurate substrate recognition by endoribonuclease toxins, definitive RNA target identification requires toxin expression in their native host. The restricted in vivo specificity of VapC-mt11 suggests that it may be enlisted to surgically manipulate pathogen physiology in response to stress.
Collapse
Affiliation(s)
- Melvilí Cintrón
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Ju-Mei Zeng
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Valdir C Barth
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Jonathan W Cruz
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Robert N Husson
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Nancy A Woychik
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA. .,Member, Rutgers Cancer Institute of New Jersey, Piscataway, 08854, USA.
| |
Collapse
|
29
|
Mandal S, Njikan S, Kumar A, Early JV, Parish T. The relevance of persisters in tuberculosis drug discovery. MICROBIOLOGY-SGM 2019; 165:492-499. [PMID: 30775961 DOI: 10.1099/mic.0.000760] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Bacterial persisters are a subpopulation of cells that exhibit phenotypic resistance during exposure to a lethal dose of antibiotics. They are difficult to target and thought to contribute to the long treatment duration required for tuberculosis. Understanding the molecular and cellular biology of persisters is critical to finding new tuberculosis drugs that shorten treatment. This review focuses on mycobacterial persisters and describes the challenges they pose in tuberculosis therapy, their characteristics and formation, how persistence leads to resistance, and the current approaches being used to target persisters within mycobacterial drug discovery.
Collapse
Affiliation(s)
- Soma Mandal
- TB Discovery Research, Infectious Disease Research Institute, 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA
| | - Samuel Njikan
- TB Discovery Research, Infectious Disease Research Institute, 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA
| | - Anuradha Kumar
- TB Discovery Research, Infectious Disease Research Institute, 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA
| | - Julie V Early
- TB Discovery Research, Infectious Disease Research Institute, 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA
| | - Tanya Parish
- TB Discovery Research, Infectious Disease Research Institute, 1616 Eastlake Ave. E, Suite 400, Seattle, WA 98102, USA
| |
Collapse
|