Doxorubicin inhibits E. coli division by interacting at a novel site in FtsZ.
The increase in antibiotic resistance has become a major health concern in recent times. It is therefore essential to identify novel antibacterial targets as well as discover and develop new antibacterial agents. FtsZ, a highly conserved bacterial protein, is responsible for the initiation of cell division in bacteria. The functions of FtsZ inside cells are tightly regulated and any perturbation in its functions leads to inhibition of bacterial division. Recent reports indicate that small molecules targeting the functions of FtsZ may be used as leads to develop new antibacterial agents. To identify small molecules targeting FtsZ and inhibiting bacterial division, we screened a U.S. FDA (Food and Drug Administration)-approved drug library of 800 molecules using an independent computational, biochemical and microbial approach. From this screen, we identified doxorubicin, an anthracycline molecule that inhibits Escherichia coli division and forms filamentous cells. A fluorescence-binding assay shows that doxorubicin interacts strongly with FtsZ. A detailed biochemical analysis demonstrated that doxorubicin inhibits FtsZ assembly and its GTPase activity through binding to a site other than the GTP-binding site. Furthermore, using molecular docking, we identified a probable doxorubicin-binding site in FtsZ. A number of single amino acid mutations at the identified binding site in FtsZ resulted in a severalfold decrease in the affinity of FtsZ for doxorubicin, indicating the importance of this site for doxorubicin interaction. The present study suggests the presence of a novel binding site in FtsZ that interacts with the small molecules and can be targeted for the screening and development of new antibacterial agents.
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India.
Pragnya
P
Panda
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India Manipal University, Manipal, Karnataka 576104, India.
Ashoka Chary
AC
Taviti
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India.
Suresh
S
Satpati
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India.
Mitali Madhusmita
MM
Kar
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India anshumandixit@gmail.com tkbeuria@gmail.com.
Anshuman
A
Dixit
Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha 751023, India anshumandixit@gmail.com tkbeuria@gmail.com.
Tushar Kant
TK
Beuria
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002455:Cell Division / Q000187:drug effects*; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004317:Doxorubicin / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D006801:Humans; D062105:Molecular Docking Simulation; D009154:Mutation; D054852:Small Molecule Libraries / Q000494:pharmacology
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D054852:Small Molecule Libraries; D004317:Doxorubicin
FtsZ; Z-ring; antibacterial target; cell division; doxorubicin; small-molecule inhibitors