Deciphering the Distinct Role for the Metal Coordination Motif in the Catalytic Activity of Mycobacterium smegmatis Topoisomerase I

Antibiotic resistance is a growing problem and may become the next major global health crisis if no timely actions are taken. Mycobacterial infections are widespread and, due to antibiotic resistance, also hard to treat and a major cause of mortality. Natural compounds have the potential to increase antibiotic effectiveness due to their resistance modulatory and antimicrobial effects. In this study, Peucedanum ostruthium extracts, fractions, and isolated compounds were investigated regarding their antimicrobial and resistance-modulatory effects as well as efflux pump inhibition in Mycobacterium smegmatis. P. ostruthium extracts were found to have anti-mycobacterial potential and resistance modulating effects on ethidium bromide activity. The major antibacterial effect was attributed to ostruthin, and we found that the more lipophilic the substrate, the greater the antimicrobial effect. Imperatorin caused potent modulatory effects by interfering with the action of the major LfrA efflux pump in M. smegmatis. The plant P. ostruthuim has a complex effect on M. smegmatis, including antibacterial, efflux pump inhibition, resistance modulation, and membrane permeabilization, and its major constituents, ostruthin and imperatorin, have a distinct role in these effects. This makes P. ostruthium and its coumarins promising therapeutics to consider in the fight against drug-resistant mycobacteria.

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Dihydroxylated 2,6-diphenyl-4-chlorophenylpyridines: Topoisomerase I and IIα dual inhibitors with DNA non-intercalative catalytic activity

European Journal of Medicinal Chemistry ◽

10.1016/j.ejmech.2017.03.048 ◽

2017 ◽

Vol 133 ◽

pp. 69-84 ◽

Cited By ~ 13

Author(s):

Ganesh Bist ◽

Seojeong Park ◽

Chanju Song ◽

Til Bahadur Thapa Magar ◽

Aarajana Shrestha ◽

...

Keyword(s):

Catalytic Activity ◽

Topoisomerase I ◽

Dual Inhibitors

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Mechanistic insights from structure of Mycobacterium smegmatis topoisomerase I with ssDNA bound to both N- and C-terminal domains

Nucleic Acids Research ◽

10.1093/nar/gkaa201 ◽

2020 ◽

Vol 48 (8) ◽

pp. 4448-4462 ◽

Cited By ~ 2

Author(s):

Nan Cao ◽

Kemin Tan ◽

Xiaobing Zuo ◽

Thirunavukkarasu Annamalai ◽

Yuk-Ching Tse-Dinh

Keyword(s):

Mycobacterium Smegmatis ◽

Topoisomerase I ◽

Physiological Role ◽

Opposite Polarity ◽

Ssdna Binding ◽

Binding Domains ◽

Type Ia ◽

Opposite Strand ◽

Negative Supercoiling ◽

Terminal Domains

Abstract Type IA topoisomerases interact with G-strand and T-strand ssDNA to regulate DNA topology. However, simultaneous binding of two ssDNA segments to a type IA topoisomerase has not been observed previously. We report here the crystal structure of a type IA topoisomerase with ssDNA segments bound in opposite polarity to the N- and C-terminal domains. Titration of small ssDNA oligonucleotides to Mycobacterium smegmatis topoisomerase I with progressive C-terminal deletions showed that the C-terminal region has higher affinity for ssDNA than the N-terminal active site. This allows the C-terminal domains to capture one strand of underwound negatively supercoiled DNA substrate first and position the N-terminal domains to bind and cleave the opposite strand in the relaxation reaction. Efficiency of negative supercoiling relaxation increases with the number of domains that bind ssDNA primarily with conserved aromatic residues and possibly with assistance from polar/basic residues. A comparison of bacterial topoisomerase I structures showed that a conserved transesterification unit (N-terminal toroid structure) for cutting and rejoining of a ssDNA strand can be combined with two different types of C-terminal ssDNA binding domains to form diverse bacterial topoisomerase I enzymes that are highly efficient in their physiological role of preventing excess negative supercoiling in the genome.

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HTLV-1 Tax Oncoprotein Binds to DNA Topoisomerase I and Inhibits Its Catalytic Activity

Virology ◽

10.1006/viro.2000.0266 ◽

2000 ◽

Vol 270 (2) ◽

pp. 291-298 ◽

Cited By ~ 17

Author(s):

Takeshi Suzuki ◽

Masami Uchida-Toita ◽

Toshiwo Andoh ◽

Mitsuaki Yoshida

Keyword(s):

Catalytic Activity ◽

Topoisomerase I ◽

Dna Topoisomerase I ◽

Dna Topoisomerase

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Fatty acid synthase inhibitor cerulenin inhibits topoisomerase I catalytic activity and augments SN-38-induced apoptosis

APOPTOSIS ◽

10.1007/s10495-012-0776-4 ◽

2012 ◽

Vol 18 (2) ◽

pp. 226-237 ◽

Cited By ~ 4

Author(s):

Na Young Jeong ◽

Jee Suk Lee ◽

Ki Soo Yoo ◽

Soojung Oh ◽

Eunok Choe ◽

...

Keyword(s):

Catalytic Activity ◽

Fatty Acid ◽

Topoisomerase I ◽

Fatty Acid Synthase ◽

Induced Apoptosis ◽

Synthase Inhibitor

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Targeting Mycobacterium tuberculosis Topoisomerase I by Small-Molecule Inhibitors

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04516-14 ◽

2014 ◽

Vol 59 (3) ◽

pp. 1549-1557 ◽

Cited By ~ 30

Author(s):

Adwait Anand Godbole ◽

Wareed Ahmed ◽

Rajeshwari Subray Bhat ◽

Erin K. Bradley ◽

Sean Ekins ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Small Molecules ◽

Metal Binding ◽

Mycobacterium Smegmatis ◽

Topoisomerase I ◽

General Strategy ◽

Content Type ◽

Dna Relaxation ◽

The Individual ◽

Related Compounds

ABSTRACTWe describe inhibition ofMycobacterium tuberculosistopoisomerase I (MttopoI), an essential mycobacterial enzyme, by two related compounds, imipramine and norclomipramine, of which imipramine is clinically used as an antidepressant. These molecules showed growth inhibition of bothMycobacterium smegmatisandM. tuberculosiscells. The mechanism of action of these two molecules was investigated by analyzing the individual steps of the topoisomerase I (topoI) reaction cycle. The compounds stimulated cleavage, thereby perturbing the cleavage-religation equilibrium. Consequently, these molecules inhibited the growth of the cells overexpressing topoI at a low MIC. Docking of the molecules on the MttopoI model suggested that they bind near the metal binding site of the enzyme. The DNA relaxation activity of the metal binding mutants harboring mutations in the DxDxE motif was differentially affected by the molecules, suggesting that the metal coordinating residues contribute to the interaction of the enzyme with the drug. Taken together, the results highlight the potential of these small molecules, which poison theM. tuberculosisandM. smegmatistopoisomerase I, as leads for the development of improved molecules to combat mycobacterial infections. Moreover, targeting metal coordination in topoisomerases might be a general strategy to develop new lead molecules.

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On the use of solid-state 45Sc NMR for structural investigations of molecular and silica-supported scandium amide catalysts

Dalton Transactions ◽

10.1039/c7dt02415k ◽

2017 ◽

Vol 46 (39) ◽

pp. 13176-13179 ◽

Cited By ~ 7

Author(s):

T. Vancompernolle ◽

X. Trivelli ◽

L. Delevoye ◽

F. Pourpoint ◽

R. M. Gauvin

Keyword(s):

Catalytic Activity ◽

Solid State ◽

Coordination Sphere ◽

Metal Coordination ◽

Structural Investigations

45Sc NMR of molecular and silica-grafted scandium amido derivatives provides information about the metal coordination sphere with links to catalytic activity.

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