A human topoisomerase IIα heterodimer with only one ATP binding site can go through successive catalytic cycles
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A human topoisomerase IIα heterodimer with only one ATP binding site can go through successive catalytic cycles. / Skouboe, Camilla; Bjergbaek, Lotte; Oestergaard, Vibe H.; Larsen, Morten K.; Knudsen, Birgitta R.; Andersen, Anni H.
I: Journal of Biological Chemistry, Bind 278, Nr. 8, 21.02.2003, s. 5768-5774.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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T1 - A human topoisomerase IIα heterodimer with only one ATP binding site can go through successive catalytic cycles
AU - Skouboe, Camilla
AU - Bjergbaek, Lotte
AU - Oestergaard, Vibe H.
AU - Larsen, Morten K.
AU - Knudsen, Birgitta R.
AU - Andersen, Anni H.
PY - 2003/2/21
Y1 - 2003/2/21
N2 - Eukaryotic DNA topoisomerase II is a dimeric nuclear enzyme essential for DNA metabolism and chromosome dynamics. It changes the topology of DNA by coupling binding and hydrolysis of two ATP molecules to the transport of one DNA duplex through a temporary break introduced in another. During this process the structurally and functionally complex enzyme passes through a cascade of conformational changes, which requires intra- and intersubunit communication. To study the importance of ATP binding and hydrolysis in relation to DNA strand transfer, we have purified and characterized a human topoisomerase IIα heterodimer with only one ATP binding site. The heterodimer was able to relax supercoiled DNA, although less efficiently than the wild type enzyme. It furthermore possessed a functional N-terminal clamp and was sensitive to ICRF-187. This demonstrates that human topoisomerase IIα can pass through all the conformations required for DNA strand passage and enzyme resetting with binding and hydrolysis of only one ATP. However, the heterodimer lacked the normal stimulatory effect of DNA on ATP binding and hydrolysis as well as the stimulatory effect of ATP on DNA cleavage. The results can be explained in a model, where efficient catalysis requires an extensive communication between the second ATP and the DNA segment to be cleaved.
AB - Eukaryotic DNA topoisomerase II is a dimeric nuclear enzyme essential for DNA metabolism and chromosome dynamics. It changes the topology of DNA by coupling binding and hydrolysis of two ATP molecules to the transport of one DNA duplex through a temporary break introduced in another. During this process the structurally and functionally complex enzyme passes through a cascade of conformational changes, which requires intra- and intersubunit communication. To study the importance of ATP binding and hydrolysis in relation to DNA strand transfer, we have purified and characterized a human topoisomerase IIα heterodimer with only one ATP binding site. The heterodimer was able to relax supercoiled DNA, although less efficiently than the wild type enzyme. It furthermore possessed a functional N-terminal clamp and was sensitive to ICRF-187. This demonstrates that human topoisomerase IIα can pass through all the conformations required for DNA strand passage and enzyme resetting with binding and hydrolysis of only one ATP. However, the heterodimer lacked the normal stimulatory effect of DNA on ATP binding and hydrolysis as well as the stimulatory effect of ATP on DNA cleavage. The results can be explained in a model, where efficient catalysis requires an extensive communication between the second ATP and the DNA segment to be cleaved.
UR - http://www.scopus.com/inward/record.url?scp=0037458744&partnerID=8YFLogxK
U2 - 10.1074/jbc.M210332200
DO - 10.1074/jbc.M210332200
M3 - Journal article
C2 - 12480934
AN - SCOPUS:0037458744
VL - 278
SP - 5768
EP - 5774
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 8
ER -
ID: 238744593