scholarly journals Characterization of DNA Binding by the Isolated N-Terminal Domain of Vaccinia Virus DNA Topoisomerase IB

Biochemistry ◽  
2017 ◽  
Vol 56 (26) ◽  
pp. 3307-3317 ◽  
Author(s):  
Benjamin Reed ◽  
Lyudmila Yakovleva ◽  
Stewart Shuman ◽  
Ranajeet Ghose
Keyword(s):  
Dna Binding ◽  
Vaccinia Virus ◽  
Dna Topoisomerase ◽  
Terminal Domain ◽  
Topoisomerase Ib

scholarly journals Characterization of the ATPase activity of topoisomerase II from Leishmania donovani and identification of residues conferring resistance to etoposide

2005 ◽  
Vol 390 (2) ◽  
pp. 419-426 ◽  
Author(s):  
Tanushri Sengupta ◽  
Mandira Mukherjee ◽  
Aditi Das ◽  
Chhabinath Mandal ◽  
Rakhee Das ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Topoisomerase Ii ◽  
Leishmania Donovani ◽  
Binding Pocket ◽  
Dna Topoisomerase ◽  
Terminal Domain ◽  
Specific Selectivity ◽  
Eukaryotic Dna ◽  
First Time

We have cloned and expressed the 43 kDa N-terminal domain of Leishmania donovani topoisomerase II. This protein has an intrinsic ATPase activity and obeys Michaelis–Menten kinetics. Cross-linking studies indicate that the N-terminal domain exists as a dimer both in the presence and absence of nucleotides. Etoposide, an effective antitumour drug, traps eukaryotic DNA topoisomerase II in a covalent complex with DNA. In the present study, we report for the first time that etoposide inhibits the ATPase activity of the recombinant N-terminal domain of L. donovani topoisomerase II. We have modelled the structure of this 43 kDa protein and performed molecular docking analysis with the drug. Mutagenesis of critical amino acids in the vicinity of the ligand-binding pocket reveals less efficient inhibition of the ATPase activity of the enzyme by etoposide. Taken together, these results provide an insight for the development of newer therapeutic agents with specific selectivity.

scholarly journals Single stranded DNA annealing is a conserved activity of telomere resolvases

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246212
Author(s):  
Siobhan L. McGrath ◽  
Shu Hui Huang ◽  
Kerri Kobryn
Keyword(s):  
Dna Binding ◽  
Dna Cleavage ◽  
Bacterial Species ◽  
Dna Binding Protein ◽  
Tyrosine Recombinase ◽  
Single Stranded Dna ◽  
Terminal Domain ◽  
Topoisomerase Ib ◽  
Replication Intermediates

Bacterial species of the genera Agrobacterium and Borrelia possess chromosomes terminated by hairpin telomeres. Replication produces dimeric replication intermediates fused via replicated telomere junctions. A specialized class of enzymes, referred to as telomere resolvases, promotes the resolution of the replicated intermediate into linear monomers terminated by hairpin telomeres. Telomere resolution is catalyzed via DNA cleavage and rejoining events mechanistically similar to those promoted by topoisomerase-IB and tyrosine recombinase enzymes. Examination of the borrelial telomere resolvase, ResT, revealed unanticipated multifunctionality; aside from its expected telomere resolution activity ResT possessed a singled-stranded DNA (ssDNA) annealing activity that extended to both naked ssDNA and ssDNA complexed with its cognate single-stranded DNA binding protein (SSB). At present, the role this DNA annealing activity plays in vivo remains unknown. We have demonstrated here that single-stranded DNA annealing is also a conserved property of the agrobacterial telomere resolvase, TelA. This activity in TelA similarly extends to both naked ssDNA and ssDNA bound by its cognate SSB. TelA’s annealing activity was shown to stem from the N-terminal domain; removal of this domain abolished annealing without affecting telomere resolution. Further, independent expression of the N-terminal domain of TelA produced a functional annealing protein. We suggest that the apparent conservation of annealing activity in two telomere resolvases, from distantly related bacterial species, implies a role for this activity in hairpin telomere metabolism. Our demonstration of the separation of the telomere resolution and annealing activities of TelA provides a platform for future experiments aimed at identifying the role DNA annealing performs in vivo.

scholarly journals A single mutation in the 729 residue modulates human DNA topoisomerase IB DNA binding and drug resistance

2008 ◽  
Vol 36 (17) ◽  
pp. 5635-5644 ◽  
Author(s):  
Carmen Losasso ◽  
Erica Cretaio ◽  
Paola Fiorani ◽  
Ilda D’Annessa ◽  
Giovanni Chillemi ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Dna Binding ◽  
Single Mutation ◽  
Dna Topoisomerase ◽  
Human Dna ◽  
Topoisomerase Ib

scholarly journals Identification and Characterization of the Regions Involved in the Nuclear Translocation of the Heterodimeric Leishmanial DNA Topoisomerase IB

PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e73565 ◽  
Author(s):  
Christopher F. Prada ◽  
Raquel Álvarez-Velilla ◽  
Rosario Díaz-Gozález ◽  
Yolanda Pérez-Pertejo ◽  
Rafael Balaña-Fouce ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Dna Topoisomerase ◽  
Topoisomerase Ib ◽  
Identification And Characterization

scholarly journals Characterization of the Single-Stranded DNA Binding Protein Encoded by the Vaccinia Virus I3 Gene

1998 ◽  
Vol 72 (4) ◽  
pp. 2917-2926 ◽  
Author(s):  
S. Craig Rochester ◽  
Paula Traktman
Keyword(s):  
Dna Binding ◽  
Vaccinia Virus ◽  
Dna Binding Protein ◽  
Mobility Shift ◽  
Single Stranded Dna ◽  
Charged Amino Acids ◽  
Double Stranded Dna ◽  
Infected Cells ◽  
Electrophoretic Mobility Shift Assays

ABSTRACT The 34-kDa protein encoded by the I3 gene of vaccinia virus is expressed at early and intermediate times postinfection and is phosphorylated on serine residues. Recombinant I3 has been expressed inEscherichia coli and purified to near homogeneity, as has the protein from infected cells. Both recombinant and endogenous I3 protein demonstrate a striking affinity for single-stranded, but not for double-stranded, DNA. The interaction with DNA is resistant to salt, exhibits low cooperativity, and appears to involve a binding site of approximately 10 nucleotides. Electrophoretic mobility shift assays indicate that numerous I3 molecules can bind to a template, reflecting the stoichiometric interaction of I3 with DNA. Sequence analysis reveals that a pattern of aromatic and charged amino acids common to many replicative single-stranded DNA binding proteins (SSBs) is conserved in I3. The inability to isolate viable virus containing an interrupted I3 allele provides strong evidence that the I3 protein plays an essential role in the viral life cycle. A likely role for I3 as an SSB involved in DNA replication and/or repair is discussed.

Characterization of a DNA-binding phosphoprotein from vaccinia virus replication complex

Virology ◽  
1978 ◽  
Vol 86 (1) ◽  
pp. 217-225 ◽  
Author(s):  
Maja Nowakowski ◽  
William Bauer ◽  
Joseph Kates
Keyword(s):  
Dna Binding ◽  
Vaccinia Virus ◽  
Virus Replication ◽  
Replication Complex
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