TY - JOUR
T1 - Reversible decatenation of kinetoplast DNA by a DNA topoisomerase from trypanosomatids
AU - Shlomai, Joseph
AU - Zadok, Anat
PY - 1983/6/25
Y1 - 1983/6/25
N2 - DNA topoisomerase activity detected in cell extracts of the trypanosomatid Crithidia fasciculata interlocks kinetoplast DNA duplex minicircles into huge catenane forms resembling the natural kinetoplast DNA networks found in trypanosomes. Catenation of duplex DNA circles is reversible and equilibrium is affected by ionic strength, and by spermidine. The reaction requires magnesium, is ATP dependent and is inhibited by high concentrations of novobiocin. Extensive homology between duplex DNA rings was not required for catenane formation since DNA circles with unrelated sequences could be interlocked into mixed network forms. Covalently sealed catenated DNA circles are specifically used as substrates for decatenation. No such preference for covalently sealed duplex DNA rings was observed for catenane formation. Its catalytic properties and DNA substrate preference, suggest a potential role for this eukaryotic topoisomerase activity in the replication of kinetoplast DNA.
AB - DNA topoisomerase activity detected in cell extracts of the trypanosomatid Crithidia fasciculata interlocks kinetoplast DNA duplex minicircles into huge catenane forms resembling the natural kinetoplast DNA networks found in trypanosomes. Catenation of duplex DNA circles is reversible and equilibrium is affected by ionic strength, and by spermidine. The reaction requires magnesium, is ATP dependent and is inhibited by high concentrations of novobiocin. Extensive homology between duplex DNA rings was not required for catenane formation since DNA circles with unrelated sequences could be interlocked into mixed network forms. Covalently sealed catenated DNA circles are specifically used as substrates for decatenation. No such preference for covalently sealed duplex DNA rings was observed for catenane formation. Its catalytic properties and DNA substrate preference, suggest a potential role for this eukaryotic topoisomerase activity in the replication of kinetoplast DNA.
UR - http://www.scopus.com/inward/record.url?scp=0021112224&partnerID=8YFLogxK
U2 - 10.1093/nar/11.12.4019
DO - 10.1093/nar/11.12.4019
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C2 - 6306572
AN - SCOPUS:0021112224
SN - 0305-1048
VL - 11
SP - 4019
EP - 4034
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 12
ER -