Binding characteristics of Ustilago maydis topoisomerase I to DNA containing secondary structures.
Publication/Presentation Date
7-15-1998
Abstract
The binding affinity of purified native Ustilago maydis topoisomerase I enzyme for radiolabeled DNA substrates with various secondary structures was determined by gel shift and equilibrium binding analysis. Topoisomerase I exhibited cooperativity in binding to DNA regardless of the substrate structure. Further analysis demonstrated that cruciform DNA has two populations of binding sites for topoisomerase I while the other substrates (single-stranded DNA, DNA molecules containing six or one mismatched base pairs, hairpin, and fully homologous duplex DNA) have a single population of binding sites. The affinity of topoisomerase I for cruciform was found to be an order of magnitude higher affinity than for any of the other substrates. The high affinity of topoisomerase I for cruciform and specificity of topoisomerase I-cruciform structure interaction were confirmed by competition experiments. These studies demonstrate the high affinity of topoisomerase I for cruciform structure.
Volume
255
Issue
2
First Page
347
Last Page
355
ISSN
0014-2956
Published In/Presented At
Thiyagarajan, M. M., Waldman, S. A., Noè, M., & Kmiec, E. B. (1998). Binding characteristics of Ustilago maydis topoisomerase I to DNA containing secondary structures. European journal of biochemistry, 255(2), 347–355. https://doi.org/10.1046/j.1432-1327.1998.2550347.x
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
9716375
Department(s)
Administration and Leadership
Document Type
Article