1
|
Liu KT, Chen SF, Chan NL. Structural insights into the assembly of type IIA topoisomerase DNA cleavage-religation center. Nucleic Acids Res 2024:gkae657. [PMID: 39077950 DOI: 10.1093/nar/gkae657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 07/09/2024] [Accepted: 07/16/2024] [Indexed: 07/31/2024] Open
Abstract
The ability to catalyze reversible DNA cleavage and religation is central to topoisomerases' role in regulating DNA topology. In type IIA topoisomerases (Top2), the formation of its DNA cleavage-religation center is driven by DNA-binding-induced structural rearrangements. These changes optimally position key catalytic modules, such as the active site tyrosine of the WHD domain and metal ion(s) chelated by the TOPRIM domain, around the scissile phosphodiester bond to perform reversible transesterification. To understand this assembly process in detail, we report the catalytic core structures of human Top2α and Top2β in an on-pathway conformational state. This state features an in trans formation of an interface between the Tower and opposing TOPRIM domain, revealing a groove for accommodating incoming G-segment DNA. Structural superimposition further unveils how subsequent DNA-binding-induced disengagement of the TOPRIM and Tower domains allows a firm grasp of the bound DNA for cleavage/religation. Notably, we identified a previously undocumented protein-DNA interaction, formed between an arginine-capped C-terminus of an α-helix in the TOPRIM domain and the DNA backbone, significantly contributing to Top2 function. This work uncovers a previously unrecognized role of the Tower domain, highlighting its involvement in anchoring and releasing the TOPRIM domain, thus priming Top2 for DNA binding and cleavage.
Collapse
Affiliation(s)
- Ko-Ting Liu
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Shin-Fu Chen
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Nei-Li Chan
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| |
Collapse
|
2
|
Kamsri B, Kamsri P, Punkvang A, Chimprasit A, Saparpakorn P, Hannongbua S, Spencer J, Oliveira ASF, Mulholland AJ, Pungpo P. Signal Propagation in the ATPase Domain of Mycobacterium tuberculosis DNA Gyrase from Dynamical-Nonequilibrium Molecular Dynamics Simulations. Biochemistry 2024; 63:1493-1504. [PMID: 38742407 PMCID: PMC11154950 DOI: 10.1021/acs.biochem.4c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/26/2024] [Accepted: 05/01/2024] [Indexed: 05/16/2024]
Abstract
DNA gyrases catalyze negative supercoiling of DNA, are essential for bacterial DNA replication, transcription, and recombination, and are important antibacterial targets in multiple pathogens, including Mycobacterium tuberculosis, which in 2021 caused >1.5 million deaths worldwide. DNA gyrase is a tetrameric (A2B2) protein formed from two subunit types: gyrase A (GyrA) carries the breakage-reunion active site, whereas gyrase B (GyrB) catalyzes ATP hydrolysis required for energy transduction and DNA translocation. The GyrB ATPase domains dimerize in the presence of ATP to trap the translocated DNA (T-DNA) segment as a first step in strand passage, for which hydrolysis of one of the two ATPs and release of the resulting inorganic phosphate is rate-limiting. Here, dynamical-nonequilibrium molecular dynamics (D-NEMD) simulations of the dimeric 43 kDa N-terminal fragment of M. tuberculosis GyrB show how events at the ATPase site (dissociation/hydrolysis of bound nucleotides) are propagated through communication pathways to other functionally important regions of the GyrB ATPase domain. Specifically, our simulations identify two distinct pathways that respectively connect the GyrB ATPase site to the corynebacteria-specific C-loop, thought to interact with GyrA prior to DNA capture, and to the C-terminus of the GyrB transduction domain, which in turn contacts the C-terminal GyrB topoisomerase-primase (TOPRIM) domain responsible for interactions with GyrA and the centrally bound G-segment DNA. The connection between the ATPase site and the C-loop of dimeric GyrB is consistent with the unusual properties of M. tuberculosis DNA gyrase relative to those from other bacterial species.
Collapse
Affiliation(s)
- Bundit Kamsri
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry,
Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Pharit Kamsri
- Division
of Chemistry, Faculty of Science, Nakhon
Phanom University, Nakhon
Phanom 48000, Thailand
| | - Auradee Punkvang
- Division
of Chemistry, Faculty of Science, Nakhon
Phanom University, Nakhon
Phanom 48000, Thailand
| | - Aunlika Chimprasit
- Department
of Chemistry, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
| | | | - Supa Hannongbua
- Department
of Chemistry, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
| | - James Spencer
- School
of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, U.K.
| | - A. Sofia F. Oliveira
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Adrian J. Mulholland
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Pornpan Pungpo
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry,
Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| |
Collapse
|
3
|
Sachdeva E, Aggarwal S, Kaur G, Gupta D, Ethayathulla AS, Kaur P. The acidic C-terminal tail of DNA Gyrase of Salmonella enterica serovar Typhi controls DNA relaxation in an acidic environment. Int J Biol Macromol 2024; 261:129728. [PMID: 38272423 DOI: 10.1016/j.ijbiomac.2024.129728] [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: 09/26/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 01/27/2024]
Abstract
The intracellular bacteria, Salmonella Typhi adapts to acidic conditions in the host cell by resetting the chromosomal DNA topology majorly controlled by DNA Gyrase, a Type II topoisomerase. DNA Gyrase forms a heterodimer A2B2 complex, which manages the DNA supercoiling and relaxation in the cell. DNA relaxation forms a part of the regulatory mechanism to activate the transcription of genes required to survive under hostile conditions. Acid-induced stress attenuates the supercoiling activity of the DNA Gyrase, resulting in DNA relaxation. Salmonella DNA becomes relaxed as the bacteria adapt to the acidified intracellular environment. Despite comprehensive studies on DNA Gyrase, the mechanism to control supercoiling activity needs to be better understood. A loss in supercoiling activity in E. coli was observed upon deletion of the non-conserved acidic C-tail of Gyrase A subunit. Salmonella Gyrase also contains an acidic tail at the C-terminus of Gyrase A, where its deletion resulted in reduced supercoiling activity compared to wild-type Gyrase. Interestingly, we also found that wild-type Gyrase compromises supercoiling activity at acidic pH 2-3, thereby causing DNA relaxation. The absence of a C-tail displayed DNA supercoiling to some extent between pH 2-9. Hence, the C-tail of Gyrase A might be one of the controlling factors that cause DNA relaxation in Salmonella at acidic pH conditions. We propose that the presence of the C-tail of GyraseA causes acid-mediated inhibition of the negative supercoiling activity of Gyrase, resulting in relaxed DNA that attracts DNA-binding proteins for controlling the transcriptional response.
Collapse
Affiliation(s)
- Ekta Sachdeva
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Shubham Aggarwal
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Gurpreet Kaur
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Deepali Gupta
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Abdul S Ethayathulla
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
| |
Collapse
|
4
|
Grzelczyk J, Pérez-Sánchez H, Carmena-Bargueño M, Oracz J, Budryn G. Effects of In Vitro Digestion of Polyphenols from Coffee on Binding Parameters to Human Topoisomerase II α. Molecules 2023; 28:5996. [PMID: 37630250 PMCID: PMC10457778 DOI: 10.3390/molecules28165996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Type II topoisomerase (TOPII) is an enzyme that influences the topology of DNA. DNA breaks generated by TOPII may result in mutagenic or cytotoxic changes in cancer cells. In this study, we characterized interactions of TOPIIα with coffee extracts and individual chlorogenic acids (CHAs) from the extracts by performing isothermal titration calorimetry (ITC) and molecular docking (MD) simulations. The study showed that the highest affinity to TOPIIα was found in green coffee (ΔG = -38.23 kJ/mol) and monochlorogenic acids fraction of coffee extracts (ΔG = -35.80 kJ/mol), resulting from the high content of polyphenols, such as CHAs, which can bind to the enzyme in the active site. Coffee extracts and their fractions maintained a high affinity for TOPIIα after simulated digestion in the presence of probiotic bacteria. It can be concluded that coffee may be a potential TOPIIα inhibitor considered as a functional food for cancer prevention.
Collapse
Affiliation(s)
- Joanna Grzelczyk
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland;
| | - Horacio Pérez-Sánchez
- Structural Bioinformatics and High-Performance Computing Research Group (BIO-HPC), Computer Engineering Department, UCAM Universidad Católica de Murcia, Guadalupe, 30107 Murcia, Spain; (H.P.-S.); (M.C.-B.)
| | - Miguel Carmena-Bargueño
- Structural Bioinformatics and High-Performance Computing Research Group (BIO-HPC), Computer Engineering Department, UCAM Universidad Católica de Murcia, Guadalupe, 30107 Murcia, Spain; (H.P.-S.); (M.C.-B.)
| | - Joanna Oracz
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland;
| | - Grażyna Budryn
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-537 Lodz, Poland;
| |
Collapse
|
5
|
Kamsri B, Pakamwong B, Thongdee P, Phusi N, Kamsri P, Punkvang A, Ketrat S, Saparpakorn P, Hannongbua S, Sangswan J, Suttisintong K, Sureram S, Kittakoop P, Hongmanee P, Santanirand P, Leanpolchareanchai J, Goudar KE, Spencer J, Mulholland AJ, Pungpo P. Bioisosteric Design Identifies Inhibitors of Mycobacterium tuberculosis DNA Gyrase ATPase Activity. J Chem Inf Model 2023; 63:2707-2718. [PMID: 37074047 DOI: 10.1021/acs.jcim.2c01376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Mutations in DNA gyrase confer resistance to fluoroquinolones, second-line antibiotics for Mycobacterium tuberculosis infections. Identification of new agents that inhibit M. tuberculosis DNA gyrase ATPase activity is one strategy to overcome this. Here, bioisosteric designs using known inhibitors as templates were employed to define novel inhibitors of M. tuberculosis DNA gyrase ATPase activity. This yielded the modified compound R3-13 with improved drug-likeness compared to the template inhibitor that acted as a promising ATPase inhibitor against M. tuberculosis DNA gyrase. Utilization of compound R3-13 as a virtual screening template, supported by subsequent biological assays, identified seven further M. tuberculosis DNA gyrase ATPase inhibitors with IC50 values in the range of 0.42-3.59 μM. The most active compound 1 showed an IC50 value of 0.42 μM, 3-fold better than the comparator ATPase inhibitor novobiocin (1.27 μM). Compound 1 showed noncytotoxicity to Caco-2 cells at concentrations up to 76-fold higher than its IC50 value. Molecular dynamics simulations followed by decomposition energy calculations identified that compound 1 occupies the binding pocket utilized by the adenosine group of the ATP analogue AMPPNP in the M. tuberculosis DNA gyrase GyrB subunit. The most prominent contribution to the binding of compound 1 to M. tuberculosis GyrB subunit is made by residue Asp79, which forms two hydrogen bonds with the OH group of this compound and also participates in the binding of AMPPNP. Compound 1 represents a potential new scaffold for further exploration and optimization as a M. tuberculosis DNA gyrase ATPase inhibitor and candidate anti-tuberculosis agent.
Collapse
Affiliation(s)
- Bundit Kamsri
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Bongkochawan Pakamwong
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Paptawan Thongdee
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Naruedon Phusi
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Pharit Kamsri
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Auradee Punkvang
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Sombat Ketrat
- School of Information Science and Technology, Vidyasirimedhi Institute of Science and Technology, Rayong 21210, Thailand
| | | | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Jidapa Sangswan
- Department of Biological Science, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Khomson Suttisintong
- National Nanotechnology Center, NSTDA, 111 Thailand Science Park, Klong Luang, Pathum Thani 12120, Thailand
| | - Sanya Sureram
- Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Prasat Kittakoop
- Chulabhorn Research Institute, Bangkok 10210, Thailand
- Chulabhorn Graduate Institute, Chemical Biology Program, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation, Bangkok 10210, Thailand
| | - Poonpilas Hongmanee
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Pitak Santanirand
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Jiraporn Leanpolchareanchai
- Department of Pharmacy, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayuthaya Road,Rajathevi, Bangkok 10400, Thailand
| | - Kirsty E Goudar
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - James Spencer
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Pornpan Pungpo
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| |
Collapse
|
6
|
Antitubercular, Cytotoxicity, and Computational Target Validation of Dihydroquinazolinone Derivatives. Antibiotics (Basel) 2022; 11:antibiotics11070831. [PMID: 35884084 PMCID: PMC9311641 DOI: 10.3390/antibiotics11070831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 02/04/2023] Open
Abstract
A series of 2,3-dihydroquinazolin-4(1H)-one derivatives (3a–3m) was screened for in vitro whole-cell antitubercular activity against the tubercular strain H37Rv and multidrug-resistant (MDR) Mycobacterium tuberculosis (MTB) strains. Compounds 3l and 3m with di-substituted aryl moiety (halogens) attached to the 2-position of the scaffold showed a minimum inhibitory concentration (MIC) of 2 µg/mL against the MTB strain H37Rv. Compound 3k with an imidazole ring at the 2-position of the dihydroquinazolin-4(1H)-one also showed significant inhibitory action against both the susceptible strain H37Rv and MDR strains with MIC values of 4 and 16 µg/mL, respectively. The computational results revealed the mycobacterial pyridoxal-5′-phosphate (PLP)-dependent aminotransferase (BioA) enzyme as the potential target for the tested compounds. In vitro, ADMET calculations and cytotoxicity studies against the normal human dermal fibroblast cells indicated the safety and tolerability of the test compounds 3k–3m. Thus, compounds 3k–3m warrant further optimization to develop novel BioA inhibitors for the treatment of drug-sensitive H37Rv and drug-resistant MTB.
Collapse
|
7
|
Pakamwong B, Thongdee P, Kamsri B, Phusi N, Kamsri P, Punkvang A, Ketrat S, Saparpakorn P, Hannongbua S, Ariyachaokun K, Suttisintong K, Sureram S, Kittakoop P, Hongmanee P, Santanirand P, Spencer J, Mulholland AJ, Pungpo P. Identification of Potent DNA Gyrase Inhibitors Active against Mycobacterium tuberculosis. J Chem Inf Model 2022; 62:1680-1690. [PMID: 35347987 DOI: 10.1021/acs.jcim.1c01390] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacterium tuberculosis DNA gyrase manipulates the DNA topology using controlled breakage and religation of DNA driven by ATP hydrolysis. DNA gyrase has been validated as the enzyme target of fluoroquinolones (FQs), second-line antibiotics used for the treatment of multidrug-resistant tuberculosis. Mutations around the DNA gyrase DNA-binding site result in the emergence of FQ resistance in M. tuberculosis; inhibition of DNA gyrase ATPase activity is one strategy to overcome this. Here, virtual screening, subsequently validated by biological assays, was applied to select candidate inhibitors of the M. tuberculosis DNA gyrase ATPase activity from the Specs compound library (www.specs.net). Thirty compounds were identified and selected as hits for in vitro biological assays, of which two compounds, G24 and G26, inhibited the growth of M. tuberculosis H37Rv with a minimal inhibitory concentration of 12.5 μg/mL. The two compounds inhibited DNA gyrase ATPase activity with IC50 values of 2.69 and 2.46 μM, respectively, suggesting this to be the likely basis of their antitubercular activity. Models of complexes of compounds G24 and G26 bound to the M. tuberculosis DNA gyrase ATP-binding site, generated by molecular dynamics simulations followed by pharmacophore mapping analysis, showed hydrophobic interactions of inhibitor hydrophobic headgroups and electrostatic and hydrogen bond interactions of the polar tails, which are likely to be important for their inhibition. Decreasing compound lipophilicity by increasing the polarity of these tails then presents a likely route to improving the solubility and activity. Thus, compounds G24 and G26 provide attractive starting templates for the optimization of antitubercular agents that act by targeting DNA gyrase.
Collapse
Affiliation(s)
- Bongkochawan Pakamwong
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Paptawan Thongdee
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Bundit Kamsri
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Naruedon Phusi
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Pharit Kamsri
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Auradee Punkvang
- Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand
| | - Sombat Ketrat
- School of Information Science and Technology, Vidyasirimedhi Institute of Science and Technology, Rayong 21210, Thailand
| | | | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Kanchiyaphat Ariyachaokun
- Department of Biological Science, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Khomson Suttisintong
- National Nanotechnology Center, NSTDA, 111 Thailand Science Park, Klong Luang, Pathum Thani 12120, Thailand
| | - Sanya Sureram
- Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Prasat Kittakoop
- Chulabhorn Research Institute, Bangkok 10210, Thailand
- Chulabhorn Graduate Institute, Chemical Biology Program, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), CHE, Ministry of Education, Bangkok 10300, Thailand
| | - Poonpilas Hongmanee
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Pitak Santanirand
- Division of Microbiology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Pornpan Pungpo
- Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| |
Collapse
|
8
|
Purushothaman M, Dhar SK, Natesh R. Role of unique loops in oligomerization and ATPase function of Plasmodium falciparum gyrase B. Protein Sci 2022; 31:323-332. [PMID: 34716632 PMCID: PMC8820116 DOI: 10.1002/pro.4217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 02/03/2023]
Abstract
DNA gyrase is an ATP dependent Type IIA topoisomerase that is unique to prokaryotes. Interestingly DNA gyrase has also been found in the apicoplasts of apicomplexan parasites like Plasmodium falciparum (Pf) the causative agent of Malaria. Gyrase B (GyrB), a subunit of gyrase A2 B2 complex has an N-terminal domain (GyrBN) which is endowed with ATPase activity. We reported earlier that PfGyrB exhibits ATP-independent dimerization unlike its bacterial counterparts. Here we report the role of two unique regions (L1 and L2) identified in PfGyrBN. Deletions of L1 alone (PfGyrBNΔL1), or L1 and L2 together (PfGyrBNΔL1ΔL2) have indicated that these regions may play an important role in ATPase activity and the oligomeric state of PfGyrBN. Our experiments show that the deletion of L1 region disrupts the dimer interface of PfGyrBN and reduces its ATPase activity. Further through ITC experiments we show that the binding affinity of ATP to PfGyrBN is reduced upon the deletion of L1 region. We have observed a reduction in ATPase activity for of all three proteins PfGyrBN, PfGyrBNΔL1, and PfGyrBNΔL1ΔL2 in presence of coumermycin. Our results suggests that L1 region of PfGyrBN is likely to be functionally important and may provide a unique dimer interface that affects its enzymatic activity. Since deletion of L1 region decreases the affinity of ATP to the protein, this region can be targeted toward designing novel inhibitors of ATP hydrolysis.
Collapse
Affiliation(s)
- Monica Purushothaman
- School of BiologyIndian Institute of Science Education and Research ThiruvananthapuramThiruvananthapuramKeralaIndia
| | - Suman Kumar Dhar
- Special Centre of Molecular MedicineJawaharlal Nehru UniversityNew DelhiIndia
| | - Ramanathan Natesh
- School of BiologyIndian Institute of Science Education and Research ThiruvananthapuramThiruvananthapuramKeralaIndia
| |
Collapse
|
9
|
Hirsch J, Klostermeier D. What makes a type IIA topoisomerase a gyrase or a Topo IV? Nucleic Acids Res 2021; 49:6027-6042. [PMID: 33905522 PMCID: PMC8216471 DOI: 10.1093/nar/gkab270] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/26/2021] [Accepted: 04/01/2021] [Indexed: 12/14/2022] Open
Abstract
Type IIA topoisomerases catalyze a variety of different reactions: eukaryotic topoisomerase II relaxes DNA in an ATP-dependent reaction, whereas the bacterial representatives gyrase and topoisomerase IV (Topo IV) preferentially introduce negative supercoils into DNA (gyrase) or decatenate DNA (Topo IV). Gyrase and Topo IV perform separate, dedicated tasks during replication: gyrase removes positive supercoils in front, Topo IV removes pre-catenanes behind the replication fork. Despite their well-separated cellular functions, gyrase and Topo IV have an overlapping activity spectrum: gyrase is also able to catalyze DNA decatenation, although less efficiently than Topo IV. The balance between supercoiling and decatenation activities is different for gyrases from different organisms. Both enzymes consist of a conserved topoisomerase core and structurally divergent C-terminal domains (CTDs). Deletion of the entire CTD, mutation of a conserved motif and even by just a single point mutation within the CTD converts gyrase into a Topo IV-like enzyme, implicating the CTDs as the major determinant for function. Here, we summarize the structural and mechanistic features that make a type IIA topoisomerase a gyrase or a Topo IV, and discuss the implications for type IIA topoisomerase evolution.
Collapse
Affiliation(s)
- Jana Hirsch
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, 48149 Muenster, Germany
| | - Dagmar Klostermeier
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, 48149 Muenster, Germany
| |
Collapse
|
10
|
Towards Conformation-Sensitive Inhibition of Gyrase: Implications of Mechanistic Insight for the Identification and Improvement of Inhibitors. Molecules 2021; 26:molecules26051234. [PMID: 33669078 PMCID: PMC7956263 DOI: 10.3390/molecules26051234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/19/2021] [Accepted: 02/20/2021] [Indexed: 12/17/2022] Open
Abstract
Gyrase is a bacterial type IIA topoisomerase that catalyzes negative supercoiling of DNA. The enzyme is essential in bacteria and is a validated drug target in the treatment of bacterial infections. Inhibition of gyrase activity is achieved by competitive inhibitors that interfere with ATP- or DNA-binding, or by gyrase poisons that stabilize cleavage complexes of gyrase covalently bound to the DNA, leading to double-strand breaks and cell death. Many of the current inhibitors suffer from severe side effects, while others rapidly lose their antibiotic activity due to resistance mutations, generating an unmet medical need for novel, improved gyrase inhibitors. DNA supercoiling by gyrase is associated with a series of nucleotide- and DNA-induced conformational changes, yet the full potential of interfering with these conformational changes as a strategy to identify novel, improved gyrase inhibitors has not been explored so far. This review highlights recent insights into the mechanism of DNA supercoiling by gyrase and illustrates the implications for the identification and development of conformation-sensitive and allosteric inhibitors.
Collapse
|
11
|
Gupta D, Tiwari P, Haque MA, Sachdeva E, Hassan MI, Ethayathulla AS, Kaur P. Structural insights into the transient closed conformation and pH dependent ATPase activity of S.Typhi GyraseB N- terminal domain. Arch Biochem Biophys 2021; 701:108786. [PMID: 33548211 DOI: 10.1016/j.abb.2021.108786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/06/2021] [Accepted: 01/29/2021] [Indexed: 11/28/2022]
Abstract
DNA Gyrase is a type II topoisomerase that utilizes the energy of ATP hydrolysis for introducing negative supercoils in DNA. The protein comprises two subunits GyrA and GyrB that form a GyrA2GyrB2 heterotetramer. GyrB subunit contains the N-terminal domain (GBNTD) for ATPase activity and the C-terminal domain (GBCTD) for interaction with GyrA and DNA. Earlier structural studies have revealed three different conformational states for GBNTD during ATP hydrolysis defined as open, semi-open, and closed. Here we report, the three-dimensional structure of a new transient closed conformation of GBNTD from Salmonella Typhi (StGBNTD) at 1.94 Å resolution. Based on the structural analysis of this transient closed conformation, we propose the role of protein in the mechanism of ATP hydrolysis. We further explored the effect of pH on ATPase activity and structural stability of the GBNTD using CD and fluorescence spectroscopy at varying pH environment. Kinetic parameters obtained from the ATPase assay were correlated with its secondary and tertiary structure at their respective pH environment. The protein possessed maximum ATPase activity and structural stability at optimum pH 8. At acidic pH, a remarkable decrease in both enzymatic activity and structural stability was observed whereas at alkaline pH there was no significant change. The structural analysis of StGBNTD reveals the role of polar interactions in stabilizing the overall dimeric conformation of the protein.
Collapse
Affiliation(s)
- Deepali Gupta
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Pragya Tiwari
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Md Anzarul Haque
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Ekta Sachdeva
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 10025, India
| | - Abdul S Ethayathulla
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
| |
Collapse
|
12
|
Structure-Based Drug Design for Tuberculosis: Challenges Still Ahead. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10124248] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Structure-based and computer-aided drug design approaches are commonly considered to have been successful in the fields of cancer and antiviral drug discovery but not as much for antibacterial drug development. The search for novel anti-tuberculosis agents is indeed an emblematic example of this trend. Although huge efforts, by consortiums and groups worldwide, dramatically increased the structural coverage of the Mycobacterium tuberculosis proteome, the vast majority of candidate drugs included in clinical trials during the last decade were issued from phenotypic screenings on whole mycobacterial cells. We developed here three selected case studies, i.e., the serine/threonine (Ser/Thr) kinases—protein kinase (Pkn) B and PknG, considered as very promising targets for a long time, and the DNA gyrase of M. tuberculosis, a well-known, pharmacologically validated target. We illustrated some of the challenges that rational, target-based drug discovery programs in tuberculosis (TB) still have to face, and, finally, discussed the perspectives opened by the recent, methodological developments in structural biology and integrative techniques.
Collapse
|
13
|
Sachdeva E, Kaur G, Tiwari P, Gupta D, Singh TP, Ethayathulla AS, Kaur P. The pivot point arginines identified in the β-pinwheel structure of C-terminal domain from Salmonella Typhi DNA Gyrase A subunit. Sci Rep 2020; 10:7817. [PMID: 32385379 PMCID: PMC7210945 DOI: 10.1038/s41598-020-64792-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/13/2020] [Indexed: 11/17/2022] Open
Abstract
The essentiality of DNA Gyrase in basic cellular processes in bacterial pathogens makes it an ideal drug target. Though the Gyrase has a conserved mechanism of action, the complete DNA wrapping and binding process is still unknown. In this study, we have identified six arginine residues R556, R612, R667, R716, R766, and R817 in the DNA GyraseA – C-terminal domain from Salmonella enterica serovar Typhi (StGyrA-CTD) to be essential for DNA wrapping and sliding by a sequence and structure analysis. Through site-directed mutagenesis and EMSA studies, we observed that the substitution of R667 (blade 3) and R716 (blade 4) in StGyrA-CTD led to loss of DNA binding. Whereas, upon mutation of residue R612 (blade2), R766 (blade5) and R817 (blade6) along with supporting residue R712 (blade 4) a decrease in binding affinity was seen. Our results indicate that R667 and R716 act as a pivot point in DNA wrapping and sliding during gyrase catalytic activity. In this study, we propose that the DNA wrapping mechanism commences with DNA binding at blade3 and blade4 followed by other blades to facilitate the DNA sliding during supercoiling activity. This study provides a better understanding of the DNA binding and wrapping mechanism of GyrA-CTD in DNA Gyrase.
Collapse
Affiliation(s)
- Ekta Sachdeva
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Gurpreet Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Pragya Tiwari
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Deepali Gupta
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Tej P Singh
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Abdul S Ethayathulla
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| |
Collapse
|
14
|
Weidlich D, Klostermeier D. Functional interactions between gyrase subunits are optimized in a species-specific manner. J Biol Chem 2020; 295:2299-2312. [PMID: 31953321 DOI: 10.1074/jbc.ra119.010245] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/03/2020] [Indexed: 11/06/2022] Open
Abstract
DNA gyrase is a bacterial DNA topoisomerase that catalyzes ATP-dependent negative DNA supercoiling and DNA decatenation. The enzyme is a heterotetramer comprising two GyrA and two GyrB subunits. Its overall architecture is conserved, but species-specific elements in the two subunits are thought to optimize subunit interaction and enzyme function. Toward understanding the roles of these different elements, we compared the activities of Bacillus subtilis, Escherichia coli, and Mycobacterium tuberculosis gyrases and of heterologous enzymes reconstituted from subunits of two different species. We show that B. subtilis and E. coli gyrases are proficient DNA-stimulated ATPases and efficiently supercoil and decatenate DNA. In contrast, M. tuberculosis gyrase hydrolyzes ATP only slowly and is a poor supercoiling enzyme and decatenase. The heterologous enzymes are generally less active than their homologous counterparts. The only exception is a gyrase reconstituted from mycobacterial GyrA and B. subtilis GyrB, which exceeds the activity of M. tuberculosis gyrase and reaches the activity of the B. subtilis gyrase, indicating that the activities of enzymes containing mycobacterial GyrB are limited by ATP hydrolysis. The activity pattern of heterologous gyrases is in agreement with structural features present: B. subtilis gyrase is a minimal enzyme, and its subunits can functionally interact with subunits from other bacteria. In contrast, the specific insertions in E. coli and mycobacterial gyrase subunits appear to prevent efficient functional interactions with heterologous subunits. Understanding the molecular details of gyrase adaptations to the specific physiological requirements of the respective organism might aid in the development of species-specific gyrase inhibitors.
Collapse
Affiliation(s)
- Daniela Weidlich
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany.
| |
Collapse
|
15
|
Design, Synthesis and Biological Evaluation of New Piperazin-4-yl-(acetyl-thiazolidine-2,4-dione) Norfloxacin Analogues as Antimicrobial Agents. Molecules 2019; 24:molecules24213959. [PMID: 31683749 PMCID: PMC6864599 DOI: 10.3390/molecules24213959] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 01/12/2023] Open
Abstract
In an effort to improve the antimicrobial activity of norfloxacin, a series of hybrid norfloxacin–thiazolidinedione molecules were synthesized and screened for their direct antimicrobial activity and their anti-biofilm properties. The new hybrids were intended to have a new binding mode to DNA gyrase, that will allow for a more potent antibacterial effect, and for activity against current quinolone-resistant bacterial strains. Moreover, the thiazolidinedione moiety aimed to include additional anti-pathogenicity by preventing biofilm formation. The resulting compounds showed promising direct activity against Gram-negative strains, and anti-biofilm activity against Gram-positive strains. Docking studies and ADMET were also used in order to explain the biological properties and revealed some potential advantages over the parent molecule norfloxacin.
Collapse
|
16
|
DNA gyrase could be a crucial regulatory factor for growth and survival of Mycobacterium leprae. Sci Rep 2019; 9:10815. [PMID: 31346236 PMCID: PMC6658535 DOI: 10.1038/s41598-019-47364-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 07/12/2019] [Indexed: 12/01/2022] Open
Abstract
Leprosy, an important infectious disease in humans caused by Mycobacterium leprae (Mle), remains endemic in many countries. Notably, the pathogen cannot be cultured in vitro, except in mouse footpads in vivo. The molecular basis of these characteristics and the mechanisms remain unknown. Consequently, analysis of Mle growth and survival is urgently needed to develop novel therapies against leprosy, including rapid, simple, and specific methods to detect infection. Here, we demonstrated the functional role and contribution of Mle-DNA gyrase, which regulates DNA topology, DNA replication, and chromosome segregation to promote bacterial growth and survival, in Mle growth and survival in vitro and in vivo. The optimum temperature for Mle-DNA gyrase activity was 30 °C. When the DNA gyrB-gyrA genes in Mycobacterium smegmatis were replaced with the Mle gyrase genes by allelic exchange, the recombinants could not grow at 37 °C. Moreover, using radiorespirometry analysis for viability of Mle bacilli, we found that Mle growth was more vigorous at 25–30 °C than at 37 °C, but was inhibited above 40 °C. These results propose that DNA gyrase is a crucial factor for Mle growth and survival and its sensitivity to temperature may be exploited in heat-based treatment of leprosy.
Collapse
|
17
|
Petrella S, Capton E, Raynal B, Giffard C, Thureau A, Bonneté F, Alzari PM, Aubry A, Mayer C. Overall Structures of Mycobacterium tuberculosis DNA Gyrase Reveal the Role of a Corynebacteriales GyrB-Specific Insert in ATPase Activity. Structure 2019; 27:579-589.e5. [PMID: 30744994 DOI: 10.1016/j.str.2019.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/13/2018] [Accepted: 01/14/2019] [Indexed: 01/03/2023]
Abstract
Despite sharing common features, previous studies have shown that gyrases from different species have been modified throughout evolution to modulate their properties. Here, we report two crystal structures of Mycobacterium tuberculosis DNA gyrase, an apo and AMPPNP-bound form at 2.6-Å and 3.3-Å resolution, respectively. These structures provide high-resolution structural data on the quaternary organization and interdomain connections of a gyrase (full-length GyrB-GyrA57)2 thus providing crucial inputs on this essential drug target. Together with small-angle X-ray scattering studies, they revealed an "extremely open" N-gate state, which persists even in the DNA-free gyrase-AMPPNP complex and an unexpected connection between the ATPase and cleavage core domains mediated by two Corynebacteriales-specific motifs, respectively the C-loop and DEEE-loop. We show that the C-loop participates in the stabilization of this open conformation, explaining why this gyrase has a lower ATPase activity. Our results image a conformational state which might be targeted for drug discovery.
Collapse
Affiliation(s)
- Stéphanie Petrella
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France; Université Paris Diderot, Sorbonne Paris Cité, 75724 Paris Cedex 15, France.
| | - Estelle Capton
- Sorbonne Université, Centre d'Immunologie et des Maladies Infectieuses-Paris, Cimi-Paris, INSERM U1135, National Reference Center for Mycobacteria, Laboratoire de Bactériologie-Hygiène, AP-HP, Hôpitaux Universitaires Pitié-Salpêtrière - Charles Foix, 75013 Paris, France
| | - Bertrand Raynal
- Plateforme de Biophysique Moléculaire, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Clément Giffard
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France; Université Paris Diderot, Sorbonne Paris Cité, 75724 Paris Cedex 15, France
| | - Aurélien Thureau
- Synchrotron SOLEIL, l'Orme des Merisiers, 91410 Saint Aubin, France
| | - Françoise Bonneté
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Institut de Biologie Physico-Chimique, CNRS UMR7099 and Université Paris Didérot, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Pedro M Alzari
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France; Université Paris Diderot, Sorbonne Paris Cité, 75724 Paris Cedex 15, France
| | - Alexandra Aubry
- Sorbonne Université, Centre d'Immunologie et des Maladies Infectieuses-Paris, Cimi-Paris, INSERM U1135, National Reference Center for Mycobacteria, Laboratoire de Bactériologie-Hygiène, AP-HP, Hôpitaux Universitaires Pitié-Salpêtrière - Charles Foix, 75013 Paris, France.
| | - Claudine Mayer
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France; Université Paris Diderot, Sorbonne Paris Cité, 75724 Paris Cedex 15, France
| |
Collapse
|
18
|
Soczek KM, Grant T, Rosenthal PB, Mondragón A. CryoEM structures of open dimers of gyrase A in complex with DNA illuminate mechanism of strand passage. eLife 2018; 7:41215. [PMID: 30457554 PMCID: PMC6286129 DOI: 10.7554/elife.41215] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/09/2018] [Indexed: 11/13/2022] Open
Abstract
Gyrase is a unique type IIA topoisomerase that uses ATP hydrolysis to maintain the negatively supercoiled state of bacterial DNA. In order to perform its function, gyrase undergoes a sequence of conformational changes that consist of concerted gate openings, DNA cleavage, and DNA strand passage events. Structures where the transported DNA molecule (T-segment) is trapped by the A subunit have not been observed. Here we present the cryoEM structures of two oligomeric complexes of open gyrase A dimers and DNA. The protein subunits in these complexes were solved to 4 Å and 5.2 Å resolution. One of the complexes traps a linear DNA molecule, a putative T-segment, which interacts with the open gyrase A dimers in two states, representing steps either prior to or after passage through the DNA-gate. The structures locate the T-segment in important intermediate conformations of the catalytic cycle and provide insights into gyrase-DNA interactions and mechanism.
Collapse
Affiliation(s)
- Katarzyna M Soczek
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Tim Grant
- Division of Physical Biochemistry, MRC National Institute for Medical Research, London, United Kingdom
| | - Peter B Rosenthal
- Division of Physical Biochemistry, MRC National Institute for Medical Research, London, United Kingdom.,Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| |
Collapse
|
19
|
A Novel Oligonucleotide Pair for Genotyping Members of the Pseudomonas Genus by Single-Round PCR Amplification of the gyrB Gene. Methods Protoc 2018. [PMCID: PMC6481054 DOI: 10.3390/mps1030024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pseudomonas is a phylogenetically diverse bacterial genus which is broadly distributed in different ecological niches, and whose taxonomy is continuously under revision. For that purpose, gyrB is one of the housekeeping genes routinely used for multilocus sequence analysis (MLSA). As we noticed that there was not a single primer pair available in the literature suitable for direct sequencing of this gene, we decided to design a unique oligonucleotide pair and to set up a polymerase chain reaction (PCR) protocol to obtain a single amplicon for the entire Pseudomonas genus. Based on the available gyrB sequence from 148 Pseudomonas species, we identified highly conserved regions to design oligonucleotides without fully degenerate positions. We then set up cycling conditions for achieving high specificity and yield of the PCR protocol. Then, we showed that the amplicons produced with this procedure were appropriate for direct sequencing with both primers, obtaining more than 95% of amplicons coverage. Finally, we demonstrated that a PCR-RFLP (restriction fragment length polymorphism) approach served to differentiate among Pseudomonas species, and even between members of the same species.
Collapse
|
20
|
Hartmann S, Gubaev A, Klostermeier D. Binding and Hydrolysis of a Single ATP Is Sufficient for N-Gate Closure and DNA Supercoiling by Gyrase. J Mol Biol 2017; 429:3717-3729. [PMID: 29032205 DOI: 10.1016/j.jmb.2017.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 11/19/2022]
Abstract
Topoisomerases catalyze the relaxation, supercoiling, catenation, and decatenation of DNA. Gyrase is a bacterial topoisomerase that introduces negative supercoils into DNA in an ATP-dependent reaction. The enzyme consists of two GyrB subunits, containing the ATPase domains, and two GyrA subunits. Nucleotide binding to gyrase B GyrB causes closing of the N-gate in gyrase, which orients bound DNA for supercoiling. N-gate re-opening after ATP hydrolysis, at the end of the supercoiling reaction, resets the enzyme for subsequent catalytic cycles. Gyrase binds and hydrolyzes two ATP molecules per catalytic cycle. Here, we dissect the role of these two binding and hydrolysis events using gyrase with one ATP-binding- and hydrolysis-deficient subunit, or with one binding-competent, but hydrolysis-deficient ATPase domain. We show that binding of a single ATP molecule induces N-gate closure. Gyrase that can only bind and hydrolyze a single ATP undergoes opening and closing of the N-gate in synchrony with ATP hydrolysis, and promotes DNA supercoiling under catalytic conditions. In contrast, gyrase that can bind two ATP molecules, but hydrolyzes only one, only supercoils DNA under stoichiometric conditions. Here, ATP bound to the hydrolysis-deficient subunit keeps the N-gate closed after hydrolysis of the other ATP and prevents further turnovers. Gyrase with only one functional ATPase domain hydrolyzes ATP with a similar rate to wild-type, but its supercoiling efficiency is reduced. Binding and hydrolysis of the second ATP may thus ensure efficient coupling of the nucleotide cycle with the supercoiling reaction by stabilizing the closed N-gate and by acting as a timer for N-gate re-opening.
Collapse
Affiliation(s)
- Simon Hartmann
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, 48149 Muenster, Germany
| | - Airat Gubaev
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, 48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, 48149 Muenster, Germany.
| |
Collapse
|
21
|
DNA topoisomerase I and DNA gyrase as targets for TB therapy. Drug Discov Today 2017; 22:510-518. [DOI: 10.1016/j.drudis.2016.11.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 11/20/2022]
|
22
|
Gubaev A, Weidlich D, Klostermeier D. DNA gyrase with a single catalytic tyrosine can catalyze DNA supercoiling by a nicking-closing mechanism. Nucleic Acids Res 2016; 44:10354-10366. [PMID: 27557712 PMCID: PMC5137430 DOI: 10.1093/nar/gkw740] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 07/20/2016] [Accepted: 08/12/2016] [Indexed: 01/10/2023] Open
Abstract
The topological state of DNA is important for replication, recombination and transcription, and is regulated in vivo by DNA topoisomerases. Gyrase introduces negative supercoils into DNA at the expense of ATP hydrolysis. It is the accepted view that gyrase achieves supercoiling by a strand passage mechanism, in which double-stranded DNA is cleaved, and a second double-stranded segment is passed through the gap, converting a positive DNA node into a negative node. We show here that gyrase with only one catalytic tyrosine that cleaves a single strand of its DNA substrate can catalyze DNA supercoiling without strand passage. We propose an alternative mechanism for DNA supercoiling via nicking and closing of DNA that involves trapping, segregation and relaxation of two positive supercoils. In contrast to DNA supercoiling, ATP-dependent relaxation and decatenation of DNA by gyrase lacking the C-terminal domains require both tyrosines and strand passage. Our results point towards mechanistic plasticity of gyrase and might pave the way for finding novel and specific mechanism-based gyrase inhibitors.
Collapse
Affiliation(s)
- Airat Gubaev
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Daniela Weidlich
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
| |
Collapse
|
23
|
Li Y, Wong YL, Lee MY, Ng HQ, Kang C. Backbone assignment of the N-terminal 24-kDa fragment of Escherichia coli topoisomerase IV ParE subunit. BIOMOLECULAR NMR ASSIGNMENTS 2016; 10:135-138. [PMID: 26482923 DOI: 10.1007/s12104-015-9652-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/16/2015] [Indexed: 06/05/2023]
Abstract
Bacterial DNA topoisomerases are important drug targets due to their importance in DNA replication and low homology to human topoisomerases. The N-terminal 24 kDa region of E. coli topoisomerase IV E subunit (eParE) contains the ATP binding pocket. Structure-based drug discovery has been proven to be an efficient way to develop potent ATP competitive inhibitors against ParEs. NMR spectroscopy is a powerful tool to understand protein and inhibitor interactions in solution. In this study, we report the backbone assignment for the N-terminal domain of E. coli ParE. The secondary structural information and the assignment will aid in structure-based antibacterial agents development targeting eParE.
Collapse
Affiliation(s)
- Yan Li
- Experimental Therapeutics Centre, Agency for Science, Technology and Research, 31 Biopolis Way Nanos, #03-01, Singapore, 138669, Singapore
| | - Ying Lei Wong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research, 31 Biopolis Way Nanos, #03-01, Singapore, 138669, Singapore
| | - Michelle Yueqi Lee
- Experimental Therapeutics Centre, Agency for Science, Technology and Research, 31 Biopolis Way Nanos, #03-01, Singapore, 138669, Singapore
| | - Hui Qi Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research, 31 Biopolis Way Nanos, #03-01, Singapore, 138669, Singapore
| | - CongBao Kang
- Experimental Therapeutics Centre, Agency for Science, Technology and Research, 31 Biopolis Way Nanos, #03-01, Singapore, 138669, Singapore.
| |
Collapse
|
24
|
Li Y, Wong YL, Ng FM, Liu B, Wong YX, Poh ZY, Then SW, Lee MY, Ng HQ, Hung AW, Cherian J, Hill J, Keller TH, Kang C. Characterization of the interaction between Escherichia coli topoisomerase IV E subunit and an ATP competitive inhibitor. Biochem Biophys Res Commun 2015; 467:961-6. [PMID: 26471301 DOI: 10.1016/j.bbrc.2015.10.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 10/07/2015] [Indexed: 10/22/2022]
Abstract
Bacterial topoisomerase IV (ParE) is essential for DNA replication and serves as an attractive target for antibacterial drug development. The X-ray structure of the N-terminal 24 kDa ParE, responsible for ATP binding has been solved. Due to the accessibility of structural information of ParE, many potent ParE inhibitors have been discovered. In this study, a pyridylurea lead molecule against ParE of Escherichia coli (eParE) was characterized with a series of biochemical and biophysical techniques. More importantly, solution NMR analysis of compound binding to eParE provides better understanding of the molecular interactions between the inhibitor and eParE.
Collapse
Affiliation(s)
- Yan Li
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Ying Lei Wong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Fui Mee Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Boping Liu
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Yun Xuan Wong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Zhi Ying Poh
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Siew Wen Then
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Michelle Yueqi Lee
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Hui Qi Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Alvin W Hung
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Joseph Cherian
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Jeffrey Hill
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - Thomas H Keller
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore
| | - CongBao Kang
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos, #03-01, 138669, Singapore.
| |
Collapse
|
25
|
Minovski N, Novic M, Solmajer T. The impact of Mycobacterium tuberculosis gyrB point mutations on 6-fluoroquinolones resistance profile: in silico mutagenesis and structure-based assessment. RSC Adv 2015. [DOI: 10.1039/c4ra16031b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The latest confirmedM. tuberculosis gyrBpoint mutations assembling thegyrBhot spot region strongly involved in 6-fluoroquinolones resistance for the first time enabled thein silicoconstruction and structure-based assays ongyrBmutant models.
Collapse
Affiliation(s)
- Nikola Minovski
- Laboratory for Chemometrics
- National Institute of Chemistry
- 1001 Ljubljana
- Slovenia
| | - Marjana Novic
- Laboratory for Chemometrics
- National Institute of Chemistry
- 1001 Ljubljana
- Slovenia
| | - Tom Solmajer
- Laboratory for Molecular Modeling
- National Institute of Chemistry
- 1001 Ljubljana
- Slovenia
| |
Collapse
|
26
|
Abstract
DNA topoisomerases are enzymes that control the topology of DNA in all cells. There are two types, I and II, classified according to whether they make transient single- or double-stranded breaks in DNA. Their reactions generally involve the passage of a single- or double-strand segment of DNA through this transient break, stabilized by DNA-protein covalent bonds. All topoisomerases can relax DNA, but DNA gyrase, present in all bacteria, can also introduce supercoils into DNA. Because of their essentiality in all cells and the fact that their reactions proceed via DNA breaks, topoisomerases have become important drug targets; the bacterial enzymes are key targets for antibacterial agents. This article discusses the structure and mechanism of topoisomerases and their roles in the bacterial cell. Targeting of the bacterial topoisomerases by inhibitors, including antibiotics in clinical use, is also discussed.
Collapse
|
27
|
Vos SM, Lyubimov AY, Hershey DM, Schoeffler AJ, Sengupta S, Nagaraja V, Berger JM. Direct control of type IIA topoisomerase activity by a chromosomally encoded regulatory protein. Genes Dev 2014; 28:1485-97. [PMID: 24990966 PMCID: PMC4083091 DOI: 10.1101/gad.241984.114] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Topoisomerases are central regulators of DNA supercoiling; how these enzymes are regulated to suit specific cellular needs is poorly understood. Vos et al. now report the structure of E. coli gyrase, a type IIA topoisomerase bound to an inhibitor, YacG. YacG represses gyrase through steric occlusion of its DNA-binding site. Further studies show that YacG engages two spatially segregated regions associated with small-molecule inhibitor interactions—fluoroquinolone antibiotics and a gyrase agonist. This study thus defines a new mechanism for the protein-based control of topoisomerases. Precise control of supercoiling homeostasis is critical to DNA-dependent processes such as gene expression, replication, and damage response. Topoisomerases are central regulators of DNA supercoiling commonly thought to act independently in the recognition and modulation of chromosome superstructure; however, recent evidence has indicated that cells tightly regulate topoisomerase activity to support chromosome dynamics, transcriptional response, and replicative events. How topoisomerase control is executed and linked to the internal status of a cell is poorly understood. To investigate these connections, we determined the structure of Escherichia coli gyrase, a type IIA topoisomerase bound to YacG, a recently identified chromosomally encoded inhibitor protein. Phylogenetic analyses indicate that YacG is frequently associated with coenzyme A (CoA) production enzymes, linking the protein to metabolism and stress. The structure, along with supporting solution studies, shows that YacG represses gyrase by sterically occluding the principal DNA-binding site of the enzyme. Unexpectedly, YacG acts by both engaging two spatially segregated regions associated with small-molecule inhibitor interactions (fluoroquinolone antibiotics and the newly reported antagonist GSK299423) and remodeling the gyrase holoenzyme into an inactive, ATP-trapped configuration. This study establishes a new mechanism for the protein-based control of topoisomerases, an approach that may be used to alter supercoiling levels for responding to changes in cellular state.
Collapse
Affiliation(s)
| | | | - David M Hershey
- Deparment of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | | | - Sugopa Sengupta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India
| | | |
Collapse
|
28
|
Gubaev A, Klostermeier D. Reprint of "The mechanism of negative DNA supercoiling: a cascade of DNA-induced conformational changes prepares gyrase for strand passage". DNA Repair (Amst) 2014; 20:130-141. [PMID: 24974097 DOI: 10.1016/j.dnarep.2014.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/03/2014] [Accepted: 01/13/2014] [Indexed: 01/04/2023]
Abstract
DNA topoisomerases inter-convert different DNA topoisomers in the cell. They catalyze the introduction or relaxation of DNA supercoils, as well as catenation and decatenation. Members of the type I topoisomerase family cleave a single strand of their double-stranded DNA substrate, whereas enzymes of the type II family cleave both DNA strands. Bacterial DNA gyrase, a type II topoisomerase, catalyzes the introduction of negative supercoils into DNA in an ATP-dependent reaction. Gyrase is not present in humans, and constitutes an attractive drug target for the treatment of bacterial and parasite infections. DNA supercoiling by gyrase is believed to occur by a strand passage mechanism, in which one segment of the double-stranded DNA substrate is passed through a (transient) break in a second segment. This mechanism requires the coordinated opening and closing of three protein interfaces, so-called gates, to ensure the directionality of strand passage toward negative supercoiling. Single molecule fluorescence resonance energy transfer experiments are ideally suited to investigate conformational changes during the catalytic cycle of DNA topoisomerases. In this review, we summarize the current knowledge on the cascade of DNA- and nucleotide-induced conformational changes in gyrase that lead to strand passage and negative supercoiling of DNA. We discuss how these conformational changes couple ATP hydrolysis to DNA supercoiling in gyrase, and how the common mechanistic principle of coordinated gate opening and closing is modulated to allow for the catalysis of different reactions by different type II topoisomerases.
Collapse
Affiliation(s)
- Airat Gubaev
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany.
| |
Collapse
|
29
|
Gubaev A, Klostermeier D. The mechanism of negative DNA supercoiling: a cascade of DNA-induced conformational changes prepares gyrase for strand passage. DNA Repair (Amst) 2014; 16:23-34. [PMID: 24674625 DOI: 10.1016/j.dnarep.2014.01.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/03/2014] [Accepted: 01/13/2014] [Indexed: 11/29/2022]
Abstract
DNA topoisomerases inter-convert different DNA topoisomers in the cell. They catalyze the introduction or relaxation of DNA supercoils, as well as catenation and decatenation. Members of the type I topoisomerase family cleave a single strand of their double-stranded DNA substrate, whereas enzymes of the type II family cleave both DNA strands. Bacterial DNA gyrase, a type II topoisomerase, catalyzes the introduction of negative supercoils into DNA in an ATP-dependent reaction. Gyrase is not present in humans, and constitutes an attractive drug target for the treatment of bacterial and parasite infections. DNA supercoiling by gyrase is believed to occur by a strand passage mechanism, in which one segment of the double-stranded DNA substrate is passed through a (transient) break in a second segment. This mechanism requires the coordinated opening and closing of three protein interfaces, so-called gates, to ensure the directionality of strand passage toward negative supercoiling. Single molecule fluorescence resonance energy transfer experiments are ideally suited to investigate conformational changes during the catalytic cycle of DNA topoisomerases. In this review, we summarize the current knowledge on the cascade of DNA- and nucleotide-induced conformational changes in gyrase that lead to strand passage and negative supercoiling of DNA. We discuss how these conformational changes couple ATP hydrolysis to DNA supercoiling in gyrase, and how the common mechanistic principle of coordinated gate opening and closing is modulated to allow for the catalysis of different reactions by different type II topoisomerases.
Collapse
Affiliation(s)
- Airat Gubaev
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany.
| |
Collapse
|
30
|
Tao J, Han J, Wu H, Hu X, Deng J, Fleming J, Maxwell A, Bi L, Mi K. Mycobacterium fluoroquinolone resistance protein B, a novel small GTPase, is involved in the regulation of DNA gyrase and drug resistance. Nucleic Acids Res 2012; 41:2370-81. [PMID: 23275532 PMCID: PMC3575795 DOI: 10.1093/nar/gks1351] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
DNA gyrase plays a vital role in resolving DNA topological problems and is the target of antibiotics such as fluoroquinolones. Mycobacterium fluoroquinolone resistance protein A (MfpA) from Mycobacterium smegmatis is a newly identified DNA gyrase inhibitor that is believed to confer intrinsic resistance to fluoroquinolones. However, MfpA does not prevent drug-induced inhibition of DNA gyrase in vitro, implying the involvement of other as yet unknown factors. Here, we have identified a new factor, named Mycobacterium fluoroquinolone resistance protein B (MfpB), which is involved in the protection of DNA gyrase against drugs both in vivo and in vitro. Genetic results suggest that MfpB is necessary for MfpA protection of DNA gyrase against drugs in vivo; an mfpB knockout mutant showed greater susceptibility to ciprofloxacin than the wild-type, whereas a strain overexpressing MfpA and MfpB showed higher loss of susceptibility. Further biochemical characterization indicated that MfpB is a small GTPase and its GTP bound form interacts directly with MfpA and influences its interaction with DNA gyrase. Mutations in MfpB that decrease its GTPase activity disrupt its protective efficacy. Our studies suggest that MfpB, a small GTPase, is required for MfpA-conferred protection of DNA gyrase.
Collapse
Affiliation(s)
- Jun Tao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, CAS, Beijing, 100101, China
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Karkare S, Chung TTH, Collin F, Mitchenall LA, McKay AR, Greive SJ, Meyer JJM, Lall N, Maxwell A. The naphthoquinone diospyrin is an inhibitor of DNA gyrase with a novel mechanism of action. J Biol Chem 2012; 288:5149-56. [PMID: 23275348 PMCID: PMC3576119 DOI: 10.1074/jbc.m112.419069] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Tuberculosis and other bacterial diseases represent a significant threat to human health. The DNA topoisomerases are excellent targets for chemotherapy, and DNA gyrase in particular is a well-validated target for antibacterial agents. Naphthoquinones (e.g. diospyrin and 7-methyljuglone) have been shown to have therapeutic potential, particularly against Mycobacterium tuberculosis. We have found that these compounds are inhibitors of the supercoiling reaction catalyzed by M. tuberculosis gyrase and other gyrases. Our evidence strongly suggests that the compounds bind to the N-terminal domain of GyrB, which contains the ATPase active site, but are not competitive inhibitors of the ATPase reaction. We propose that naphthoquinones bind to GyrB at a novel site close to the ATPase site. This novel mode of action could be exploited to develop new antibacterial agents.
Collapse
Affiliation(s)
- Shantanu Karkare
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Chim N, Owens CP, Contreras H, Goulding CW. Withdrawn. Infect Disord Drug Targets 2012:CDTID-EPUB-20121116-2. [PMID: 23167715 PMCID: PMC3695056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Withdrawn by the publisher.
Collapse
Affiliation(s)
- Nicholas Chim
- Department of Molecular Biology and Biochemistry, University of California, Irvine CA 92697, USA
| | - Cedric P. Owens
- Department of Molecular Biology and Biochemistry, University of California, Irvine CA 92697, USA
| | - Heidi Contreras
- Department of Molecular Biology and Biochemistry, University of California, Irvine CA 92697, USA
| | - Celia W. Goulding
- Department of Molecular Biology and Biochemistry, University of California, Irvine CA 92697, USA
- Department of Pharmaceutical Sciences, University of California, Irvine CA 92697, USA
| |
Collapse
|
33
|
Lanz MA, Klostermeier D. The GyrA-box determines the geometry of DNA bound to gyrase and couples DNA binding to the nucleotide cycle. Nucleic Acids Res 2012; 40:10893-903. [PMID: 22977179 PMCID: PMC3510516 DOI: 10.1093/nar/gks852] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
DNA gyrase catalyses the adenosine triphosphate-dependent introduction of negative
supercoils into DNA. The enzyme binds a DNA-segment at the so-called DNA-gate and cleaves
both DNA strands. DNA extending from the DNA-gate is bound at the perimeter of the
cylindrical C-terminal domains (CTDs) of the GyrA subunit. The CTDs are believed to
contribute to the wrapping of DNA around gyrase in a positive node as a prerequisite for
strand passage towards negative supercoiling. A conserved seven amino acid sequence motif
in the CTD, the so-called GyrA-box, has been identified as a hallmark feature of gyrases.
Mutations of the GyrA-box abolish supercoiling. We show here that the GyrA-box marginally
stabilizes the CTDs. Although it does not contribute to DNA binding, it is required for
DNA bending and wrapping, and it determines the geometry of the bound DNA. Mutations of
the GyrA-box abrogate a DNA-induced conformational change of the gyrase N-gate and
uncouple DNA binding and adenosine triphosphate hydrolysis. Our results implicate the
GyrA-box in coordinating DNA binding and the nucleotide cycle.
Collapse
Affiliation(s)
- Martin A Lanz
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | | |
Collapse
|
34
|
Karkare S, Yousafzai F, Mitchenall LA, Maxwell A. The role of Ca²⁺ in the activity of Mycobacterium tuberculosis DNA gyrase. Nucleic Acids Res 2012; 40:9774-87. [PMID: 22844097 PMCID: PMC3479174 DOI: 10.1093/nar/gks704] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
DNA gyrase is the only type II topoisomerase in Mycobacterium tuberculosis and needs to catalyse DNA supercoiling, relaxation and decatenation reactions in order to fulfil the functions normally carried out by gyrase and DNA topoisomerase IV in other bacteria. We have obtained evidence for the existence of a Ca2+-binding site in the GyrA subunit of M. tuberculosis gyrase. Ca2+ cannot support topoisomerase reactions in the absence of Mg2+, but partial removal of Ca2+ from GyrA by dialysis against EGTA leads to a modest loss in relaxation activity that can be restored by adding back Ca2+. More extensive removal of Ca2+ by denaturation of GyrA and dialysis against EGTA results in an enzyme with greatly reduced enzyme activities. Mutation of the proposed Ca2+-binding residues also leads to loss of activity. We propose that Ca2+ has a regulatory role in M. tuberculosis gyrase and suggest a model for the modulation of gyrase activity by Ca2+ binding.
Collapse
Affiliation(s)
- Shantanu Karkare
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | | | | |
Collapse
|
35
|
Gubaev A, Klostermeier D. Potassium ions are required for nucleotide-induced closure of gyrase N-gate. J Biol Chem 2012; 287:10916-21. [PMID: 22343632 DOI: 10.1074/jbc.m111.308247] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DNA gyrase catalyzes ATP-dependent negative supercoiling of DNA by a strand passage mechanism that requires coordinated opening and closing of three protein interfaces, the N-, DNA-, and C-gates. ATP binding to the GyrB subunits of gyrase causes dimerization and N-gate closure. The closure of the N-gate is a key step in the gyrase catalytic cycle, as it captures the DNA segment to be transported and poises gyrase toward strand passage. We show here that K(+) ions are required for DNA supercoiling but are dispensable for ATP-independent DNA relaxation. Although DNA binding, distortion, wrapping, and DNA-induced narrowing of the N-gate occur in the absence of K(+), nucleotide-induced N-gate closure depends on their presence. Our results provide evidence that K(+) ions relay small conformational changes in the nucleotide-binding pocket to the formation of a tight dimer interface at the N-gate by connecting regions from both GyrB monomers and suggest an important role for K(+) in synchronization of N-gate closure and DNA-gate opening.
Collapse
Affiliation(s)
- Airat Gubaev
- Institute for Physical Chemistry, University of Münster, D-48149 Münster, Germany.
| | | |
Collapse
|
36
|
Collin F, Karkare S, Maxwell A. Exploiting bacterial DNA gyrase as a drug target: current state and perspectives. Appl Microbiol Biotechnol 2011; 92:479-97. [PMID: 21904817 PMCID: PMC3189412 DOI: 10.1007/s00253-011-3557-z] [Citation(s) in RCA: 364] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/08/2011] [Accepted: 08/18/2011] [Indexed: 12/17/2022]
Abstract
DNA gyrase is a type II topoisomerase that can introduce negative supercoils into DNA at the expense of ATP hydrolysis. It is essential in all bacteria but absent from higher eukaryotes, making it an attractive target for antibacterials. The fluoroquinolones are examples of very successful gyrase-targeted drugs, but the rise in bacterial resistance to these agents means that we not only need to seek new compounds, but also new modes of inhibition of this enzyme. We review known gyrase-specific drugs and toxins and assess the prospects for developing new antibacterials targeted to this enzyme.
Collapse
Affiliation(s)
- Frédéric Collin
- Department Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | | | | |
Collapse
|
37
|
Combinatorially-generated library of 6-fluoroquinolone analogs as potential novel antitubercular agents: a chemometric and molecular modeling assessment. J Mol Model 2011; 18:1735-53. [DOI: 10.1007/s00894-011-1179-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 07/04/2011] [Indexed: 01/15/2023]
|
38
|
Bates AD, Berger JM, Maxwell A. The ancestral role of ATP hydrolysis in type II topoisomerases: prevention of DNA double-strand breaks. Nucleic Acids Res 2011; 39:6327-39. [PMID: 21525132 PMCID: PMC3159449 DOI: 10.1093/nar/gkr258] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/04/2011] [Accepted: 04/06/2011] [Indexed: 12/27/2022] Open
Abstract
Type II DNA topoisomerases (topos) catalyse changes in DNA topology by passing one double-stranded DNA segment through another. This reaction is essential to processes such as replication and transcription, but carries with it the inherent danger of permanent double-strand break (DSB) formation. All type II topos hydrolyse ATP during their reactions; however, only DNA gyrase is able to harness the free energy of hydrolysis to drive DNA supercoiling, an energetically unfavourable process. A long-standing puzzle has been to understand why the majority of type II enzymes consume ATP to support reactions that do not require a net energy input. While certain type II topos are known to 'simplify' distributions of DNA topoisomers below thermodynamic equilibrium levels, the energy required for this process is very low, suggesting that this behaviour is not the principal reason for ATP hydrolysis. Instead, we propose that the energy of ATP hydrolysis is needed to control the separation of protein-protein interfaces and prevent the accidental formation of potentially mutagenic or cytotoxic DSBs. This interpretation has parallels with the actions of a variety of molecular machines that catalyse the conformational rearrangement of biological macromolecules.
Collapse
Affiliation(s)
- Andrew D Bates
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
| | | | | |
Collapse
|
39
|
Wu J, Zhang Z, Mitchenall LA, Maxwell A, Deng J, Zhang H, Zhou Y, Chen YY, Wang DC, Zhang XE, Bi L. The dimer state of GyrB is an active form: implications for the initial complex assembly and processive strand passage. Nucleic Acids Res 2011; 39:8488-502. [PMID: 21745817 PMCID: PMC3201873 DOI: 10.1093/nar/gkr553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In a previous study, we presented the dimer structure of DNA gyrase B′ domain (GyrB C-terminal domain) from Mycobacterium tuberculosis and proposed a ‘sluice-like’ model for T-segment transport. However, the role of the dimer structure is still not well understood. Cross-linking and analytical ultracentrifugation experiments showed that the dimer structure exists both in the B′ protein and in the full-length GyrB in solution. The cross-linked dimer of GyrB bound GyrA very weakly, but bound dsDNA with a much higher affinity than that of the monomer state. Using cross-linking and far-western analyses, the dimer state of GyrB was found to be involved in the ternary GyrA–GyrB–DNA complex. The results of mutational studies reveal that the dimer structure represents a state before DNA cleavage. Additionally, these results suggest that the dimer might also be present between the cleavage and reunion steps during processive transport.
Collapse
Affiliation(s)
- Jinjun Wu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Impact of the E540V amino acid substitution in GyrB of Mycobacterium tuberculosis on quinolone resistance. Antimicrob Agents Chemother 2011; 55:3661-7. [PMID: 21646485 DOI: 10.1128/aac.00042-11] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amino acid substitutions conferring resistance to quinolones in Mycobacterium tuberculosis have generally been found within the quinolone resistance-determining regions (QRDRs) in the A subunit of DNA gyrase (GyrA) rather than the B subunit of DNA gyrase (GyrB). To clarify the contribution of an amino acid substitution, E540V, in GyrB to quinolone resistance in M. tuberculosis, we expressed recombinant DNA gyrases in Escherichia coli and characterized them in vitro. Wild-type and GyrB-E540V DNA gyrases were reconstituted in vitro by mixing recombinant GyrA and GyrB. Correlation between the amino acid substitution and quinolone resistance was assessed by the ATP-dependent DNA supercoiling assay, quinolone-inhibited supercoiling assay, and DNA cleavage assay. The 50% inhibitory concentrations of eight quinolones against DNA gyrases bearing the E540V amino acid substitution in GyrB were 2.5- to 36-fold higher than those against the wild-type enzyme. Similarly, the 25% maximum DNA cleavage concentrations were 1.5- to 14-fold higher for the E540V gyrase than for the wild-type enzyme. We further demonstrated that the E540V amino acid substitution influenced the interaction between DNA gyrase and the substituent(s) at R-7, R-8, or both in quinolone structures. This is the first detailed study of the contribution of the E540V amino acid substitution in GyrB to quinolone resistance in M. tuberculosis.
Collapse
|
41
|
Baker NM, Weigand S, Maar-Mathias S, Mondragón A. Solution structures of DNA-bound gyrase. Nucleic Acids Res 2011; 39:755-66. [PMID: 20870749 PMCID: PMC3025574 DOI: 10.1093/nar/gkq799] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/20/2010] [Accepted: 08/24/2010] [Indexed: 12/02/2022] Open
Abstract
The DNA gyrase negative supercoiling mechanism involves the assembly of a large gyrase/DNA complex and conformational rearrangements coupled to ATP hydrolysis. To establish the complex arrangement that directs the reaction towards negative supercoiling, bacterial gyrase complexes bound to 137- or 217-bp DNA fragments representing the starting conformational state of the catalytic cycle were characterized by sedimentation velocity and small-angle X-ray scattering (SAXS) experiments. The experiments revealed elongated complexes with hydrodynamic radii of 70-80 Å. Molecular envelopes calculated from these SAXS data show 2-fold symmetric molecules with the C-terminal domain (CTD) of the A subunit and the ATPase domain of the B subunit at opposite ends of the complexes. The proposed gyrase model, with the DNA binding along the sides of the molecule and wrapping around the CTDs located near the exit gate of the protein, adds new information on the mechanism of DNA negative supercoiling.
Collapse
Affiliation(s)
- Nicole M. Baker
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Dr, Evanston, IL 60208, USA and DND-CAT Synchrotron Research Center, APS/ANL Building 432A, 9700 S. Cass Ave., Argonne, IL 60439, USA
| | - Steven Weigand
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Dr, Evanston, IL 60208, USA and DND-CAT Synchrotron Research Center, APS/ANL Building 432A, 9700 S. Cass Ave., Argonne, IL 60439, USA
| | - Sarah Maar-Mathias
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Dr, Evanston, IL 60208, USA and DND-CAT Synchrotron Research Center, APS/ANL Building 432A, 9700 S. Cass Ave., Argonne, IL 60439, USA
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Dr, Evanston, IL 60208, USA and DND-CAT Synchrotron Research Center, APS/ANL Building 432A, 9700 S. Cass Ave., Argonne, IL 60439, USA
| |
Collapse
|
42
|
Schoeffler AJ, May AP, Berger JM. A domain insertion in Escherichia coli GyrB adopts a novel fold that plays a critical role in gyrase function. Nucleic Acids Res 2010; 38:7830-44. [PMID: 20675723 PMCID: PMC2995079 DOI: 10.1093/nar/gkq665] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
DNA topoisomerases manage chromosome supercoiling and organization in all forms of life. Gyrase, a prokaryotic heterotetrameric type IIA topo, introduces negative supercoils into DNA by an ATP-dependent strand passage mechanism. All gyrase orthologs rely on a homologous set of catalytic domains for function; however, these enzymes also can possess species-specific auxiliary regions. The gyrases of many gram-negative bacteria harbor a 170-amino acid insertion of unknown architecture and function in the metal- and DNA-binding TOPRIM domain of the GyrB subunit. We have determined the structure of the 212 kDa Escherichia coli gyrase DNA binding and cleavage core containing this insert to 3.1 Å resolution. We find that the insert adopts a novel, extended fold that braces the GyrB TOPRIM domain against the coiled-coil arms of its partner GyrA subunit. Structure-guided deletion of the insert greatly reduces the DNA binding, supercoiling and DNA-stimulated ATPase activities of gyrase. Mutation of a single amino acid at the contact point between the insert and GyrA more modestly impairs supercoiling and ATP turnover, and does not affect DNA binding. Our data indicate that the insert has two functions, acting as a steric buttress to pre-configure the primary DNA-binding site, and serving as a relay that may help coordinate communication between different functional domains.
Collapse
Affiliation(s)
- Allyn J. Schoeffler
- Department of Molecular and Cell Biology, California Institute for Quantitative Biosciences, University of California, Berkeley and Fluidigm Corporation, South San Francisco, CA 94080, USA,*To whom correspondence should be addressed. Tel: 505 643 9483; Fax: 505 666 2768;
| | - Andrew P. May
- Department of Molecular and Cell Biology, California Institute for Quantitative Biosciences, University of California, Berkeley and Fluidigm Corporation, South San Francisco, CA 94080, USA
| | - James M. Berger
- Department of Molecular and Cell Biology, California Institute for Quantitative Biosciences, University of California, Berkeley and Fluidigm Corporation, South San Francisco, CA 94080, USA,*To whom correspondence should be addressed. Tel: 505 643 9483; Fax: 505 666 2768;
| |
Collapse
|
43
|
Piton J, Petrella S, Delarue M, André-Leroux G, Jarlier V, Aubry A, Mayer C. Structural insights into the quinolone resistance mechanism of Mycobacterium tuberculosis DNA gyrase. PLoS One 2010; 5:e12245. [PMID: 20805881 PMCID: PMC2923608 DOI: 10.1371/journal.pone.0012245] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/21/2010] [Indexed: 12/04/2022] Open
Abstract
Mycobacterium tuberculosis DNA gyrase, an indispensable nanomachine involved in the regulation of DNA topology, is the only type II topoisomerase present in this organism and is hence the sole target for quinolone action, a crucial drug active against multidrug-resistant tuberculosis. To understand at an atomic level the quinolone resistance mechanism, which emerges in extensively drug resistant tuberculosis, we performed combined functional, biophysical and structural studies of the two individual domains constituting the catalytic DNA gyrase reaction core, namely the Toprim and the breakage-reunion domains. This allowed us to produce a model of the catalytic reaction core in complex with DNA and a quinolone molecule, identifying original mechanistic properties of quinolone binding and clarifying the relationships between amino acid mutations and resistance phenotype of M. tuberculosis DNA gyrase. These results are compatible with our previous studies on quinolone resistance. Interestingly, the structure of the entire breakage-reunion domain revealed a new interaction, in which the Quinolone-Binding Pocket (QBP) is blocked by the N-terminal helix of a symmetry-related molecule. This interaction provides useful starting points for designing peptide based inhibitors that target DNA gyrase to prevent its binding to DNA.
Collapse
Affiliation(s)
- Jérémie Piton
- Unité de Dynamique Structurale des Macromolécules, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
- URA 2185, CNRS, Paris, France
- UPMC Univ Paris 06, Paris, France
| | | | - Marc Delarue
- Unité de Dynamique Structurale des Macromolécules, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
- URA 2185, CNRS, Paris, France
| | - Gwénaëlle André-Leroux
- URA 2185, CNRS, Paris, France
- Unité de Biochimie Structurale, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
| | - Vincent Jarlier
- UPMC Univ Paris 06, EA1541, Bactériologie-Hygiène, Paris, France
| | - Alexandra Aubry
- UPMC Univ Paris 06, EA1541, Bactériologie-Hygiène, Paris, France
| | - Claudine Mayer
- Unité de Dynamique Structurale des Macromolécules, Département de Biologie Structurale et Chimie, Institut Pasteur, Paris, France
- URA 2185, CNRS, Paris, France
- Université Paris Diderot Paris 7, Paris, France
- * E-mail:
| |
Collapse
|
44
|
Type IIA topoisomerase inhibition by a new class of antibacterial agents. Nature 2010; 466:935-40. [DOI: 10.1038/nature09197] [Citation(s) in RCA: 514] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Accepted: 05/20/2010] [Indexed: 11/08/2022]
|
45
|
Sissi C, Palumbo M. In front of and behind the replication fork: bacterial type IIA topoisomerases. Cell Mol Life Sci 2010; 67:2001-24. [PMID: 20165898 PMCID: PMC11115839 DOI: 10.1007/s00018-010-0299-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 01/26/2010] [Accepted: 02/01/2010] [Indexed: 01/03/2023]
Abstract
Topoisomerases are vital enzymes specialized in controlling DNA topology, in particular supercoiling and decatenation, to properly handle nucleic acid packing and cell dynamics. The type IIA enzymes act by cleaving both strands of a double helix and having another strand from the same or another molecule cross the DNA gate before a re-sealing event completes the catalytic cycle. Here, we will consider the two types of IIA prokaryotic topoisomerases, DNA Gyrase and Topoisomerase IV, as crucial regulators of bacterial cell cycle progression. Their synergistic action allows control of chromosome packing and grants occurrence of functional transcription and replication processes. In addition to displaying a fascinating molecular mechanism of action, which transduces chemical energy into mechanical energy by means of large conformational changes, these enzymes represent attractive pharmacological targets for antibacterial chemotherapy.
Collapse
Affiliation(s)
- Claudia Sissi
- Department of Pharmaceutical Sciences, University of Padova, Via Marzolo 5, 35131, Padua, Italy.
| | | |
Collapse
|