Take our Survey

Reference: Roca J (2004) The path of the DNA along the dimer interface of topoisomerase II. J Biol Chem 279(24):25783-8

Reference Help

Abstract

The eukaryotic DNA topoisomerase II is a dyadic enzyme that, upon ATP binding, transports one duplex DNA (T-segment) through a transient double-stranded break in another (G-segment). The path of the T-segment involves the sequential crossing of three gates along the dimer interface: the entrance or N-gate, the DNA gate, and the exit or C-gate. Coordination among these gates is critical for dimer stability and the prevention of chromosome damage. This study examines DNA transactions by yeast topoisomerase II derivatives defective in gate function. The results indicate that, although the N-gate is not required for G-segment cleavage, the DNA gate per se is not able to widen unless ATP binds to the N-gate. Next, a captured T-segment cannot be held in the interdomainal region between the N-gate and the DNA gate. Finally, the G-segment can be religated while a T-segment is held in the central cavity of the enzyme between the DNA gate and the C-gate. These quaternary couplings for gate opening and closing suggest that topoisomerase II ensures a transient DNA gating state, during which dimer interface contacts are maximized and backtracking of the transported DNA is minimized.

Reference Type
Journal Article | Research Support, Non-U.S. Gov't
Authors
Roca J
Primary Lit For
Additional Lit For
Review For

Interaction Annotations

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations

Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference